Submitted by Dr. Mario on 2009, June 9 - 06:12
Термин атипическая гемангиома печени; используют в УЗИ диагностике, имеется ввиду такие гемангиомы, которые имеет не-классическую (гиперэхогенную),атипическую презентацию. Как правило они в разной степени гипоэхогенны, особенно в центральной части (могут быть гетерогенными) с гипрэхогенным ободком. Такая презентация объясняется последствиями центрального геморрагического некрозом, формированием рубцов или миксоматозными изменениями. Некоторые авторы заявляют, что процент таких атипичных гемангиом достигает 40% (!) (Moody and Wilson 1993).
В отношении КТ и МРТ; более распространён термин: гемангиомы с атипическим контрастированием; как правило такая атипия объясняется изменениями в окружающей печёночной ткани, например наличие фиброзных изменений за счёт активного вирусного гепатита С: посмотрите эту статью (можно скачать PDF):
http://www.springerlink.com/content/n11n762475112635/
Masakatsu Tsurusaki1, 3 Contact Information, Ryota Kawasaki1, Masato Yamaguchi1, Koji Sugimoto1, Takumi Fukumoto2, Yonson Ku2 and Kazuro Sugimura1
(1) Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunokicho, Chuo-ku, Kobe 650-0017, Japan
(2) Department of Hepato-Biliary and Pancreatic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
(3) Present address: Department of Diagnostic Radiology, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
Received: 29 September 2008 Accepted: 10 December 2008 Published online: 3 May 2009
Abstract We report a case of hemangioma with an atypical vascular enhancement pattern. The hemangioma showed peripheral rim enhancement at the arterial phase during dynamic magnetic resonance imaging, and the peripheral enhanced zone was still apparent during the delayed phase, as shown on double-phase computed tomography hepatic arteriography. The rim enhancement pattern of this case, mimicking that of hepatocellular carcinoma, may be due to the surrounding liver parenchymal fibrotic change caused by an active hepatitis C viral infection.
Другие разновидности гемангиом которые могут попадать под термин атипические; включают в себя:
1.Быстро накапливающие гемангиомы (как Вы написали "вспыхивающие").
2.Медленно накапливающие гемангиомы (до 24 часов!), их бывает очень сложно дифференцировать.
3.Кальцинированные гемангиомы: редко встречаются, кальцинация может быть как по периферии, так и в центре (по типу флеболитов), в диагностике таких гемангиом помогает МРТ, мы увидим гиперинтенсивное на Т2W образование с кальцинацией.
4.Гиалинизированная гемангиома: считается что гиалинизирование, это последняя стадия инволюции гемангиомы, патоморфологи описывают выраженные процессы фиброза с облитерацией сосудов. Такие гемангиомы практически невозможно диагностировать при помощи радиологических методов (Вы об этом как раз писали).
5.Кистозные и мультикистозные гемангиомы: очень редкий вариант, мультикистозная гемангиома была описана только единожды (Hihara et al. 1990), отличить от других вариантов кист печени практически невозможно.
6.Гемангиомы с уровнями жидкости: также очень редкий вариант, на УЗИ выглядят гипоэхогенными, уровни выявляются только на КТ и МРТ.
7.Гемангиомы с артерио-венозным шунтированием: хотя артерио-венозное шунтирование связывают с злокачественными образованиями, этот феномен описан и при таких доброкачественных образованиях, как гемангиомы. Данные феномен можно визуализировать на динамическом КТ с усилением или МРТ с контрастированием; наблюдается раннее паренхиматозное контрастирование с наполнением портальной вены. В литературе описано, что > 25% гемангиом могут наблюдаться с таким феноменом, чаще в гемангиомах с быстрым наполнением.
8.Гемангиомы с ретракцией капсулы: описаны при ассоциации гемангиомы с злокачественными опухолями (холангиокарцинома, гемангиоэндотелиома и метастазами); существует всего несколько наблюдений описанных в литературе.
Оригинальный английский текст; на основе которого был подготовлен данный обзор:
Focal Liver Lesions
Detection, Characterization,
Ablation
With Contributions by
A. Adam · T. Albrecht · V. Apell · R. S. Arellano · C. Bartolozzi · R Basilico · E. Batini
M. Bazzocchi · C. D. Becker · L. Bolondi · M. P. Bondioni · G. Brancatelli · L. Bonomo
F. Caseiro-Alves · M. Celestre · D. Cioni · M. Colombo · A. Conti · D. O. Cosgrove
L. Crocetti · C. Del Frate · C. Della Pina · A. D’Errico · F. Di Fabio · K. Eichler · J. Fasel
M. P. Federle · A. Ferreira · A. Filippone · D. A. Gervais · A. R. Gillams · J. A. Goode
L. Grazioli · R. M. Hammerstingl · T. K. Helmberger · M. Holtappels · K. M. Josten
C. Kulinna · R. Lagalla · A. Laghi · T. Lehnert · R. Lencioni · S. Leoni · J. Lera · K. H. Link
P. Loubeyre · M. Mack · P. Majno · D. Mathieu · G. Mentha · M. Midiri · M. Mörschel
S. Montagnani · P. Morel · K. Mortelè · P. R. Mueller · P. Paolantonio · R. Passariello
F. Piscaglia · R. Pozzi-Mucelli · E. Rocchi · G. Ronchi · T. Sabharwal · T. A. Sagban
I. Sansoni · W. Schima · W. V. Schwarz · L. Staib · R. Straub · S. Terraz · R. Thimm
K. Tischbirek · A. Venturi · V. Vilgrain · T. J. Vogl · T. F. Weigel · K. Zayed · C. Zuiani
Foreword by
A. L. Baert
Springer-Verlag Berlin Heidelberg 2005
8.7
Atypical Patterns:
8.7.1
Hemangioma with Echoic Border
An atypical but suggestive appearance of hemangiomas
at US is the following: the lesion has an echoic
border, which is seen as a thick echoic rind or a
thin echoic rim (Moody and Wilson 1993). Unlike
typical hemangiomas, this type of hemangioma has
an internal echo pattern that is at least partially hypoechoic.
The central low echogenicity is assumed
to correspond to previous hemorrhagic necrosis,
scarring, or myxomatous changes. Although, the real
percentage is unknown, some authors have reported
that 40% of all hemangiomas could have this atypia
(Moody and Wilson 1993).
8.7.2
Large, Heterogeneous Hemangioma
Large hemangiomas are often heterogeneous
(Yamashita et al. 1994). They are termed giant
hemangiomas when they exceed 4 cm in diameter
(Nelson and Chezmar 1990; Valls et al. 1996).
However, some authors defi ne giant hemangiomas
as lesions greater than 6 cm or 12 cm in diameter
(Choi et al. 1989; Danet et al. 2003). Large hemangiomas
may be responsible for liver enlargement and
abdominal discomfort.
At US, large hemangiomas often appear heterogeneous.
On non-enhanced CT scans, lesions appear
hypoattenuating and heterogeneous with marked
central areas of low attenuation. After intravenous
administration of contrast material, the typical
early, peripheral, globular enhancement is observed.
However, during the venous and delayed phases, the
progressive centripetal enhancement of the lesion,although present, does not lead to complete fi lling
(Fig. 8.6). At MR imaging, T1-weighted sequences
show a sharply marginated, hypointense mass with a
cleft-like area of lower intensity and sometimes with
hypointense internal septa. T2-weighted images show
a markedly hyperintense cleft-like area and some hypointense
internal septa within a hyperintense mass.
The enhancement is equivalent to that seen at CT, with
incomplete fi lling of the lesion; the cleft-like area remains
hypointense, as do the internal septa (Fig. 8.7)
(Choi et al. 1989). The MR imaging fi ndings of giant
hemangiomas are closely correlated with the macroscopic
appearance, which demonstrates changes such
as hemorrhage, thrombosis, extensive hyalinization,
liquefaction, and fi brosis. The central cleft-like area
may be due to cystic degeneration, liquefaction or
myxoid tissue (Choi et al. 1989; Danet et al. 2003).
Modifi cations of internal components such as
thrombosis and hemorrhage may induce compression
of biliary and vascular structures (Coumbaras
et al. 2002).
8.7.3
Rapidly Filling Hemangioma
Rapidly fi lling hemangiomas are not very frequent
(16% of all hemangiomas). However, rapid fi lling
seems to occur signifi cantly more often in small hemangiomas
(42% of hemangiomas <1 cm in diameter)
(Figs. 8.3, 8.5) (Hanafusa et al. 1995).
CT and MR imaging show a particular enhancement
pattern: immediate homogeneous enhancement
at arterial-phase CT or contrast-enhancement
T1-weighted MR imaging (Figs. 8.3, 8.5) (Semelka
and Sofka 1997). This feature makes differentiation
from other hypervascular tumors diffi cult. T2-
weighted images may be helpful, but hypervascular
tumors such as islet cell metastases are also hyperintense
on such images. Accurate diagnosis is made
with delayed-phase CT or MR imaging because hemangiomas
remain hyperattenuating or hyperintense,
whereas hypervascular metastases do not (Figs. 8.3,
8.5). Another important fi nding in diagnosis of hemangioma
is attenuation equivalent to that of the aorta
during all phases of CT (Figs. 8.3, 8.5) (Quinn and
Benjamin 1992). At Doppler US, unusual arterial
fl ow may be present.
Because histopathologic confi rmation is usually
not performed, the mechanism of the enhancement
is not clearly understood; however, the difference in
enhancement patterns may be due to a difference in
the size of the blood spaces. It is likely that the smallerthe lesion, the more rapid is the spread of contrast
material within it (Hanafusa et al. 1995). This theory
could explain the high proportion of small hemangiomas
with rapid and complete filling.
8.7.4
Very Slow Filling Hemangioma
They appear as hypoattenuating lesions on multiphasic
examination or they have tiny enhancing dots that
do not progress to the classic globular enhancement
(Fig. 8.8). Their incidence is estimated at between
8%–16% of cases. They are problematic in patients
with malignancy (Jang et al. 2003).
8.7.5
Calcified Hemangioma
Although hemangiomas in the soft tissue, gastrointestinal
tract, retroperitoneum, and mediastinum
may show calcifi cations (phleboliths, which are
pathognomonic for the tumor), hepatic hemangiomas
rarely demonstrate calcifi cations (Darlak et al.
1990; Scatarige et al. 1983). Calcifi ed hemangiomas
are mostly found incidentally.
Calcifications may occur in the marginal or central
portion of the lesion (Mitsudo et al. 1995). A particular
pattern consists of multiple spotty calcifi cations,
which correspond to phleboliths. However, large, organizedcalcifi cations are also possible. Some calcifi
ed hemangiomas may demonstrate poor enhancement,
especially at CT (Mitsudo et al. 1995).
The finding of a nonenhancing hepatic tumor with
calcifi cations should not preclude the diagnosis of
hemangioma. High signal intensity in non-calcifi ed
areas of the lesion on T2-weighted MR images can
help in diagnosis.
8.7.6
Hyalinized Hemangioma
Hyalinized hepatic hemangiomas are rare (Cheng et
al. 1995; Tung et al. 1994). Some authors have suggested
that hyalinized hemangiomas represent an end
stage of hemangioma involution. Such hemangiomas
do not demonstrate any particular symptoms.
Hyalinization of a hemangioma changes its radiological
features, thus making diagnosis before biopsy
virtually impossible. Hyalinized hemangiomas show
only slight high signal intensity on T2-weighted MR
images (Cheng et al. 1995). Moreover, there is lack of
early enhancement on dynamic contrast-enhanced
images. Slight peripheral enhancement may occur in
the late phase (Cheng et al. 1995). MR imaging does
not allow differentiation of hyalinized hemangiomas
from malignant hepatic tumors.
Pathologic examination reveals extensive fi brous
tissue and obliteration of vascular channels (Cheng
et al. 1995).
8.7.7
Cystic or Multilocular Hemangioma
Cavernous hemangiomas with a large central cavity
that contains fl uid are very rare. To our knowledge,
only one hemangioma with a multilocular cystic component
has been reported in the literature (Hihara
et al. 1990). This entity does not demonstrate any
particular symptoms.
Defi nite diagnosis of such hemangiomas with
imaging is diffi cult. This atypia may be due to cystic
degeneration caused by central thrombosis and hemorrhage.
8.7.8
Hemangioma with Fluid–Fluid Level
Fluid–fl uid levels within hemangiomas are very rare.
To our knowledge, only three articles on this entity
have been published (Azencot et al. 1993; Itai et
al. 1987; Soyer et al. 1998). The patient may present
with abdominal pain.
US shows a hyperechoic or hypoechoic pattern.
The fl uid–fl uid level is not seen at US (Azencot et
al. 1993; Soyer et al. 1998). CT and especially MR
imaging easily demonstrate this feature (Itai et al.
1987).
8.7.9
Pedunculated Hemangioma
Pedunculated hemangiomas are very rare. To our
knowledge, only two cases have been reported in the
literature (Ellis et al. 1985; Tran-Minh et al. 1991).
They can be asymptomatic or complicated by subacute
torsion and infarction.
At US, the origin of the lesion may be diffi cult
to recognize. The lesion can be attached to the liver
by a thin pedicle, which is nearly undetectable at
imaging. Multiplanar reconstruction of CT scans
and coronal or sagittal MR imaging can be helpful.
At CT and MR imaging, the diagnosis is made
by demonstrating the typical enhancement pattern
and the typical signal intensities on both T1- and
T2-weighted images.
Complicated pedunculated hemangiomas must be
resected.
8.7.10
Hemangioma with Arterial-Portal Venous Shunt
Arterial-portal venous shunts are mainly associated
with hepatic malignancy but can also be seen
in benign liver masses, in particular hemangiomas
(Winograd and Palubinskas 1977; Shimada et al.
1994). This entity is usually asymptomatic.
An arterial-portal venous shunt can be detected
with helical CT or dynamic contrast-enhanced MR
imaging. The fi ndings consist of early parenchymal
enhancement associated with early fi lling of the
portal vein (Hanafusa et al. 1995). Arterio-portal
shunts are found in 25% of hemangiomas. They are
not related to the lesion size but they are more frequently
seen in hemangiomas with rapid enhancement
(Fig. 8.3) (Kim et al. 2001b).
8.7.11
Hemangioma with Capsular Retraction
Capsular retraction is usually associated with malignant
tumors such as cholangiocarcinoma, epithelioid
hemangioendothelioma, or metastases. This fi nding
is very rare in benign liver tumors and has been
described in very few hemangiomas (Fig. 8.9) (Yang
et al. 2001).
8.8
Hemangioma Developing in Abnormal Liver
8.8.1
Hemangioma in Fatty Liver
Diffuse fatty infi ltration of the liver is a common
fi nding and may change the typical appearances of
lesions, making them more diffi cult to characterize
at imaging.
At US, a hemangioma may appear slightly hyperechoic,
isoechoic, or hypoechoic relative to a fatty
liver (Marsh et al. 1989). Posterior acoustic enhancement
is usually observed. At non-enhanced CT, the
lesion may be hyperattenuating relative to the liver
or may not seen (Fig. 8.10). Contrast-enhanced CT
shows peripheral enhancement and delayed fi lling,
an appearance similar to that of a hemangioma in a
normal liver (Freeny and Marks 1986). However, at
arterial-phase imaging, the hemangioma may be isoattenuating
relative to the liver. MR imaging is more
helpful than CT and allows reliable detection and
differentiation of hemangiomas from other hepatic
masses (Fig. 8.11) (Stark et al. 1985). Hemangiomas
may also be accompanied by a focal spared zone as
seen in malignant tumors in fatty liver (Jang et al.
2003).
8.8.2
Hemangioma in Liver Cirrhosis
With progressive cirrhosis, hemangiomas are likely
to decrease in size and become more fi brotic and
diffi cult to diagnose radiologically (Brancatelli et
al. 2001).
8.9
Association with Other Lesions
8.9.1
Multiple Hemangiomas
Hemangiomas are multiple in 10% of cases (Ishak
and Rabin 1975). Multiple hemangiomas generally
consist of a few scattered lesions (Yamashita et al.
1994). They often have typical imaging features.
8.9.2
Hemangiomatosis
Hemangiomas, even giant ones, are usually well defi
ned (Valls et al. 1996). In rare cases, the lesion may
be large and ill defi ned, replacing almost the whole
hepatic parenchyma. This entity is seen more oftenin infants than in adults and may be associated with
cardiac failure and high mortality. In adults, hemangiomatosis
can be asymptomatic.
Если Вы владеете английским, я представляю Вашему вниманию две статьи по теме, где наиболее полно раскрыта эта тема.
http://radiographics.rsnajnls.org/cgi/content/full/20/2/379
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(Radiographics. 2000;20:379-397.)
© RSNA, 2000
SCIENTIFIC EXHIBIT |
Imaging of Atypical Hemangiomas of the Liver with Pathologic Correlation1
Valérie Vilgrain, MD, Leila Boulos, MD , Marie-Pierre Vullierme, MD , Alban Denys, MD , Benoît Terris, MD and Yves Menu, MD
1 From the Departments of Radiology (V.V., L.B., M.P.V., A.D., Y.M.) and Pathology (B.T.), Hôpital Beaujon, 100 boulevard du Général Leclerc, 92118 Clichy, France. Presented as a scientific exhibit at the 1998 RSNA scientific assembly. Received June 9, 1999; revision requested July 9 and received August 9; accepted August 12. Address reprint requests to V.V. (e-mail: valerie.vilgrain@bjn.ap-hop-paris.fr).
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Top
Abstract
Introduction
Compared with the imaging features of typical hepatic hemangiomas, the imaging features of atypical hepatic hemangiomas have not been well studied or well described. Knowledge of the entire spectrum of atypical hepatic hemangiomas is important and can help one avoid most diagnostic errors. A frequent type of atypical hepatic hemangioma is a lesion with an echoic border at ultrasonography. Less frequent types are large, heterogeneous hemangiomas; rapidly filling hemangiomas; calcified hemangiomas; hyalinized hemangiomas; cystic or multilocular hemangiomas; hemangiomas with fluid-fluid levels; and pedunculated hemangiomas. Adjacent abnormalities consist of arterial–portal venous shunt, capsular retraction, and surrounding nodular hyperplasia; hemangiomas can also develop in cases of fatty liver infiltration. Associated lesions include multiple hemangiomas, hemangiomatosis, focal nodular hyperplasia, and angiosarcoma. Types of atypical evolution are hemangiomas enlarging over time and hemangiomas appearing during pregnancy. Complications consist of inflammation, Kasabach-Merritt syndrome, intratumoral hemorrhage, hemoperitoneum, volvulus, and compression of adjacent structures. In some cases, such as large heterogeneous hemangiomas, calcified hemangiomas, pedunculated hemangiomas, or hemangiomas developing in diffuse fatty liver, a specific diagnosis can be established with imaging, especially magnetic resonance imaging. However, in other atypical cases, the diagnosis will remain uncertain at imaging, and these cases will require histopathologic examination.
Index Terms: Angioma, gastrointestinal tract, 761.3194 • Liver neoplasms, CT, 761.12112 • Liver neoplasms, diagnosis, 761.3194 • Liver neoplasms, MR, 761.121411, 761.12143 • Liver neoplasms, US, 761.12983
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Hemangioma is the most common benign hepatic tumor. The prevalence of hemangioma in the general population ranges from 1%–2% (1) to 20% (2); the female-to-male ratio varies from 2:1 to 5:1. Because hepatic hemangiomas are frequent, are most often asymptomatic, and have a very low rate of complications, this lesion does not require surgical resection. Therefore, the role of imaging is to help diagnose the lesion. In cases of typical hemangioma, imaging modalities are highly reliable for diagnosis, especially magnetic resonance (MR) imaging, which has a sensitivity and specificity of greater than 90% (1).
Conversely, the presence of atypical features in cases of hepatic hemangioma may lead to misdiagnosis and confusion with other lesions. In this article, we review the atypical features of hepatic hemangiomas. Specific topics discussed are typical hemangiomas, a frequent atypical pattern (hemangioma with echoic border), less frequent atypical patterns, atypical adjacent abnormalities, hemangioma in fatty liver infiltration, association with other lesions, atypical evolution, complications, biopsy, and differential diagnosis.
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The classic hemangioma is an asymptomatic lesion that is discovered at routine examination or autopsy. At ultrasonography (US), the typical appearance is a homogeneous, hyperechoic mass with well-defined margins and posterior acoustic enhancement (Fig 1a) (3).
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The computed tomographic (CT) findings consist of a hypoattenuating
lesion on nonenhanced images (
). After intravenous administration
of contrast material, arterial-phase CT shows early, peripheral,
globular enhancement of the lesion (
). The attenuation
of the peripheral nodules is equal to that of the adjacent aorta
(
). Venous-phase CT shows centripetal enhancement that progresses
to uniform filling (
) (
,
). This enhancement persists
on delayed-phase images (
) (
).
At MR imaging, hemangiomas are characterized by well-defined margins and high signal intensity on T2-weighted images, which is identical to that of cerebrospinal fluid (6,7). Specificity is improved by using serial gadolinium-enhanced gradient-echo imaging (6). The gadolinium intake is similar to the intake of iodinated contrast material during enhanced CT. With T2-weighted spin-echo and dynamic gadolinium-enhanced T1-weighted gradient-echo sequences, the sensitivity and specificity of MR imaging are 98% and the accuracy is 99% (8).
Technetium-99m pertechnetate–labeled red blood cell scintigraphy is a relatively specific examination for diagnosis of hemangiomas. With this method, there is decreased activity on early dynamic images and increased activity on delayed blood pool images obtained over 30–50 minutes (3). Numerous studies have demonstrated that the sensitivity of single photon emission CT is superior to that of planar imaging; the former technique has a sensitivity of 78% and an accuracy of 80% (9). Therefore, radionuclide scintigraphy is a valuable tool when the diagnosis cannot be achieved with other imaging modalities. However, radionuclide scintigraphy for identification of hemangiomas is not performed routinely in all centers, especially outside the United States.
The imaging features of a hemangioma depend on its size; typical hemangiomas are mostly less than 3 cm in diameter (3).
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An atypical but suggestive appearance of hemangiomas at US is the following: The lesion has an echoic border, which is seen as a thick echoic rind or a thin echoic rim (1). Unlike typical hemangiomas, this type of hemangioma has an internal echo pattern that is at least partially hypoechoic (Fig 2). The central low echogenicity is assumed to correspond to previous hemorrhagic necrosis, scarring, or myxomatous changes. The corresponding CT and MR imaging appearances of hemangiomas with echoic borders are not precisely described in the literature; in most such cases, we have observed typical patterns at CT or MR imaging.
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Although the real percentage is unknown, some authors have reported
that 40% of all
hemangioma
s could have this atypia (
).
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Large, Heterogeneous Hemangioma
Large hemangiomas are often heterogeneous (10). They are termed giant hemangiomas when they exceed 4 cm in diameter (3,11). However, some authors define giant hemangiomas as lesions greater than 6 cm (12) or 12 cm (13) in diameter. Large hemangiomas may be responsible for liver enlargement and abdominal discomfort.
At US, large hemangiomas often appear heterogeneous (Fig 3a).
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On nonenhanced CT scans, lesions appear hypoattenuating and
heterogeneous with marked central areas of low attenuation (
).
After intravenous administration of contrast material,
the typical early, peripheral, globular enhancement is observed
(
). However, during the venous and delayed phases, the
progressive centripetal enhancement of the lesion, although
present, does not lead to complete filling (
).
At MR imaging, T1-weighted sequences show a sharply marginated, hypointense mass with a cleftlike area of lower intensity and sometimes with hypointense internal septa (Fig 3e). T2-weighted images show a markedly hyperintense cleftlike area and some hypointense internal septa within a hyperintense mass (Fig 3f) (7). The enhancement is equivalent to that seen at CT, with incomplete filling of the lesion; the cleftlike area remains hypointense, as do the internal septa (12).
The MR imaging findings of giant hemangiomas are closely correlated with the macroscopic appearance, which demonstrates changes such as hemorrhage, thrombosis, extensive hyalinization, liquefaction, and fibrosis. The central cleftlike area may be due to cystic degeneration or liquefaction (12). The internal septa may correspond to poorly cellular fibrous tissue (12).
Rapidly Filling Hemangioma
Rapidly filling hemangiomas are not very frequent (16% of all hemangiomas). However, rapid filling seems to occur significantly more often in small hemangiomas (42% of hemangiomas <1 cm in diameter) (14).
CT and MR imaging show a particular enhancement pattern: immediate homogeneous enhancement at arterial-phase CT or contrast-enhanced T1-weighted MR imaging (Fig 4a) (2). This feature makes differentiation from other hypervascular tumors difficult. T2-weighted images may be helpful, but hypervascular tumors such as islet cell metastases are also hyperintense on such images.
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Accurate diagnosis is made with delayed-phase CT or MR imaging
because
hemangioma
s remain hyperattenuating or hyperintense,
whereas hypervascular metastases do not (
). Another important
finding in diagnosis of
hemangioma
is attenuation equivalent
to that of the aorta during all phases of CT (
). At Doppler
US, unusual arterial flow may be present.
Because histopathologic confirmation is usually not performed, the mechanism of the enhancement is not clearly understood; however, the difference in enhancement patterns may be due to a difference in the size of the blood spaces. It is likely that the smaller the lesion, the more rapid is the spread of contrast material within it (14). This theory could explain the high proportion of small hemangiomas with rapid and complete filling.
Calcified Hemangioma
Although hemangiomas in the soft tissue, gastrointestinal tract, retroperitoneum, and mediastinum may show calcifications (phleboliths, which are pathognomonic for the tumor), hepatic hemangiomas rarely demonstrate calcifications (15, 16). Calcified hemangiomas are mostly found incidentally.
Calcifications may occur in the marginal or central portion of the lesion (Fig 5) (17). A particular pattern consists of multiple spotty calcifications, which correspond to phleboliths (Fig 6) (17). However, large, organized calcifications are also possible. Some calcified hemangiomas may demonstrate poor enhancement, especially at CT (17).
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The finding of a nonenhancing hepatic tumor with calcifications
should not preclude the diagnosis of
hemangioma
. High signal
intensity in noncalcified areas of the lesion on T2-weighted
MR images can help in diagnosis (
).
Hyalinized Hemangioma
Hyalinized hepatic hemangiomas are rare (18,19). Some authors have suggested that hyalinized hemangiomas represent an end stage of hemangioma involution. Such hemangiomas do not demonstrate any particular symptoms.
Hyalinization of a hemangioma changes its radiologic features, thus making diagnosis before biopsy virtually impossible. Whereas typical hemangiomas are characterized by marked high signal intensity on T2-weighted MR images, hyalinized hemangiomas show only slight high signal intensity (18).
Moreover, there is lack of early enhancement on dynamic contrast-enhanced images (Fig 7a) (7,20). Slight peripheral enhancement may occur in the late phase (Fig 7b) (18). MR imaging does not allow differentiation of hyalinized hemangiomas from malignant hepatic tumors (Fig 7c).
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Pathologic examination reveals extensive fibrous tissue (
)
(
,
) and obliteration of vascular channels (
). These
findings are responsible for the decreased signal intensity
on T2-weighted MR images and for the lack of enhancement, respectively.
Percutaneous biopsy is indicated in these cases (
).
Cystic or Multilocular Hemangioma
Cavernous hemangiomas with a large central cavity that contains fluid are very rare (21). To our knowledge, only one hemangioma with a multilocular cystic component has been reported in the literature (22). This entity does not demonstrate any particular symptoms.
US can show a nonspecific lesion with a central fluid-filled component, which is sometimes multilocular. CT may show some degree of peripheral enhancement; the cystic component does not enhance. On MR images, the lesion appears as one or several fluid-filled cavities, which are sometimes associated with peripheral enhancement.
Definite diagnosis of such hemangiomas with imaging is difficult. This atypia may be due to cystic degeneration caused by central thrombosis and hemorrhage.
Hemangioma with Fluid-Fluid Level
Fluid-fluid levels within hemangiomas are very rare. To our knowledge, only three articles on this entity have been published (23–25). The patient may present with abdominal pain.
US shows a hyperechoic or hypoechoic pattern. The fluid-fluid level is not seen at US (23–25).
CT and especially MR imaging easily demonstrate this feature. Stagnant blood may be responsible for the sedimentation effect at CT and MR imaging, with the superior fluid layer consisting of unclotted serous blood and the inferior fluid layer consisting of red blood cells. The superior layer is hypoattenuating on CT scans, isointense to muscle on T1-weighted MR images, and markedly hyperintense on T2-weighted MR images. The inferior layer is of higher attenuation on CT scans, hyperintense to muscle on T1-weighted images, and slightly hyperintense on T2-weighted images (Fig 8) (25).
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Nevertheless, fluid-fluid levels in hepatic lesions do not indicate
a specific diagnosis and can be observed in both malignant and
benign conditions (
). Some authors have suggested that fluid-fluid
levels that are clearly demonstrated with CT or MR imaging but
not visible at US could be suggestive of
hemangioma
(
).
Pathologic correlation shows that fluid-fluid levels in hemangiomas correspond to the sedimentation effect within a large vascular space (25). Histologic examination may be required for diagnosis.
Pedunculated Hemangioma
Pedunculated hemangiomas are very rare. To our knowledge, only two cases have been reported in the literature (26,27). They can be asymptomatic or complicated by subacute torsion and infarction.
At US, the origin of the lesion may be difficult to recognize. The lesion can be attached to the liver by a thin pedicle, which is nearly undetectable at imaging. Multiplanar reconstruction of CT scans and coronal or sagittal MR imaging can be helpful. At CT and MR imaging, the diagnosis is made by demonstrating the typical enhancement pattern and the typical signal intensities on both T1- and T2-weighted images (Fig 9).
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Pathologic examination is usually not required. Complicated
pedunculated
hemangioma
s must be resected immediately.
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Hemangioma with Arterial–Portal Venous Shunt
Arterial–portal venous shunts are mainly associated with hepatic malignancy but can also be seen in benign liver masses (28,29), in particular hemangiomas. Fourteen cases of hemangiomas with arterial–portal venous shunts are reported in the literature. This entity is usually asymptomatic.
An arterial–portal venous shunt can be detected with helical CT or dynamic contrast-enhanced MR imaging (Fig 10). The findings consist of early parenchymal enhancement (14) associated with early filling of the portal vein.
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Hemangioma with Capsular Retraction
Capsular retraction is usually associated with malignant tumors
such as cholangiocarcinoma, epithelioid hemangioendothelioma,
or metastases. We have seen one case of
hemangioma
associated
with capsular retraction (
), which was diagnosed by means
of surgical biopsy and absence of change over time.
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A possible mechanism could be fibrous degeneration. However,
in our case, the high signal intensity on T2-weighted MR images
and the histopathologic findings were not suggestive of a fibrous
component.
Nodular Hyperplasia Surrounding Hemangioma
Regenerative nodular hyperplasia has been reported at the periphery of hypervascular tumors such as fibrolamellar carcinoma (30).
We have seen one case of regenerative nodular hyperplasia surrounding a hepatic hemangioma; to our knowledge, this finding has not been reported in the literature. At imaging, the central part of the lesion was similar to that of a typical hemangioma and the peripheral part enhanced homogeneously on arterial-phase CT and MR images, producing a rimlike appearance (Fig 12). Pathologic examination revealed a typical hemangioma surrounded by a fleshy, tan rim 1–2 cm thick.
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The arterial supply is thought to be derived from the tumor
vasculature; this theory may explain the development of parenchymal
hyperplasia (
). Although the association with regenerative
nodular hyperplasia is very rare, it does not rule out the diagnosis
of
hemangioma
. Furthermore, if biopsy is needed, awareness of
this phenomenon allows one to avoid false-negative results due
to sampling of the regenerative area.
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Diffuse fatty infiltration of the liver is a common finding and may change the typical appearances of lesions, making them more difficult to characterize at imaging.
At US, a hemangioma may appear slightly hyperechoic, isoechoic, or hypoechoic relative to a fatty liver (31). Posterior acoustic enhancement is usually observed.
At nonenhanced CT, the lesion may be hyperattenuating relative to the liver (Fig 13a) or may not be seen. Contrast-enhanced CT shows peripheral enhancement and delayed filling, an appearance similar to that of a hemangioma in a normal liver (Fig 13b, 13c) (32). However, at arterial-phase imaging, the hemangioma may be isoattenuating relative to the liver (Fig 13b).
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MR imaging is more helpful than CT and allows reliable detection
and differentiation of
hemangioma
s from other hepatic masses
(
) (
).
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Multiple Hemangiomas
Hemangiomas are multiple in 10% of cases (34). Multiple hemangiomas generally consist of a few scattered lesions (10). They often have typical imaging features (Fig 14).
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Hemangiomatosis
Hemangioma
s, even giant ones, are usually well defined (
).
In rare cases, the lesion may be large and ill defined, replacing
almost the whole hepatic parenchyma. This entity is seen more
often in infants than in adults and may be associated with cardiac
failure and high mortality. In adults,
hemangioma
tosis can be
asymptomatic.
US demonstrates large, hypoechoic masses with ill-defined margins to the normal parenchyma (Fig 15a) (11). Numerous confluent hyperechoic masses are also observed (35). At CT, the typical peripheral enhancement may be lacking (11); the most suggestive feature is delayed enhancement (Fig 15b–15d). MR imaging enables correct diagnosis by demonstrating characteristic signal intensities on both T1- and T2-weighted images (Fig 15e).
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However, histologic confirmation is mandatory in doubtful cases.
Associated Lesions
Focal Nodular Hyperplasia.—The coexistence of hepatic hemangioma and focal nodular hyperplasia (Fig 16) has been incidentally noted in the literature (34,36,37). More recent studies suggest that this association is quite frequent (23% of cases) and not fortuitous (38). It has also been suggested that the association is more frequent in cases of multiple focal nodular hyperplasia (33%) (39). Focal nodular hyperplasia is considered to be a hyperplastic response due to focal increased arterial flow in the hepatic parenchyma and, like hemangioma, is thought to have a vascular origin.
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In the reported cases, the association between
hemangioma
and
focal nodular hyperplasia has been seen in women who had previously
used oral contraceptives (100% of cases) (
). It is thought
that prolonged use of oral contraceptives may facilitate identification
of this association, possibly by affecting the growth of these
tumors.
When the tumors have typical imaging features, the diagnosis can be made with confidence.
Angiosarcoma.—To our knowledge, there is only one report of malignant transformation of a hepatic hemangioma in the literature (40). Another report described a cavernous hemangioma surrounded by angiosarcoma (41), and the authors raised the hypothesis of malignant transformation of a hemangioma.
In such cases, clinical symptoms can be mild (abdominal discomfort) and anemia may be noted. US shows a heterogeneous mass. At CT, irregular enhancement and possible internal or subcapsular bleeding may suggest the malignant component. MR imaging can show the same features.
At histologic examination, the association of central features of cavernous hemangioma and peripheral endothelial cells with nuclear atypia and mitosis suggests possible malignant transformation.
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Hemangioma Enlarging over Time
Most hemangiomas remain stable in size (42) or demonstrate minimal increase in diameter over time (43). Very few observations of significant enlargement of a hemangioma have been reported (42–45). They include one case of enlargement during pregnancy and two cases during estrogen use.
Enlarged hemangiomas can be asymptomatic or may manifest as an abdominal mass or pain. The US, CT, and MR imaging features are identical to those of typical hemangiomas (Fig 17).
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The mechanism of the enlargement is believed to be vascular
ectasia (
). A role for estrogens in
hemangioma
enlargement
is suspected (
) but has never been proved (
).
Despite the growth of the lesion, if imaging features are characteristic of hemangioma, the diagnosis can still be made confidently with imaging.
Hemangiomas Appearing during Pregnancy
One observation of three hemangiomas appearing during pregnancy has been reported in the literature (46). No particular symptoms were present. The imaging features were those of typical hemangiomas. This observation emphasizes the possible role of estrogens.
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The overall complication rate varies from 4.5% to 19.7% (20). Complications are mostly observed in large hemangiomas and can be divided into alterations of internal architecture such as inflammation; coagulation, which could lead to systemic disorders; hemorrhage, which can cause hemoperitoneum; volvulus; and compression of adjacent structures.
Inflammatory Process
Some cases of inflammatory processes complicating giant hemangiomas have been reported (42). The prevalence is probably underestimated. Signs and symptoms of an inflammatory process include low-grade fever, weight loss, abdominal pain, accelerated erythrocyte sedimentation rate, anemia, thrombocytosis, and increased fibrinogen level.
The imaging features are those of giant hemangioma. Histologic signs of inflammation may not be detected. A possible explanation is the release of immune mediators by hepatic endothelial cells lining the hemangioma. Clinical and laboratory abnormalities may disappear after surgical excision of the hemangioma.
Kasabach-Merritt Syndrome
Kasabach-Merritt syndrome is a rare complication of hepatic hemangiomas in adults. It is a coagulopathy consisting of intravascular coagulation, clotting, and fibrinolysis within the hemangioma (47). The initially localized coagulopathy may progress to secondary increased systemic fibrinolysis and thrombocytopenia (48), leading to a fatal outcome in 20%–30% of patients.
Intratumoral Hemorrhage
Intratumoral hemorrhage is rarely encountered in hepatic hemangiomas. It can occur spontaneously or after anticoagulation therapy. The symptoms consist of acute-onset vomiting and epigastric pain (49).
The bleeding is suggested by intratumoral high attenuation on nonenhanced CT scans (Fig 18a) and high signal intensity on T1-weighted MR images (Fig 18b). When the typical enhancement features of hemangioma are present in association with marked high signal intensity on T2-weighted MR images, the diagnosis can be made (Fig 18c). If not, histopathologic examination allows correct diagnosis (Fig 18d).
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Hemoperitoneum Due to Spontaneous Rupture of Hemangioma
Spontaneous rupture of a
hemangioma
is unusual. Clinical symptoms
include acute abdominal pain.
Imaging procedures reveal hemoperitoneum. Intraperitoneal clotting may be seen adjacent to the bleeding hemangioma. MR imaging is very sensitive in detection of bleeding by showing high signal intensity on T1-weighted images. Angiography can be useful for diagnosis, and embolization can be performed, thus allowing planned hepatic resection (50).
Volvulus of Pedunculated Hemangioma
To our knowledge, only one case of volvulus of a pedunculated hemangioma has been reported (27). The mechanism of the volvulus is twisting of the lesion around its pedicle. Clinical symptoms consist of acute abdominal pain.
The lesion may be considered to arise from the liver or to be separate from the hepatic parenchyma. In the reported case, enhancement of the lesion on contrast-enhanced CT scans was observed only at the periphery; the lesion contained central hemorrhagic necrosis at pathologic examination (27).
Compression Due to Hemangioma
Dilatation of Intrahepatic Bile Ducts Due to Giant Hemangioma.—One case of a giant hemangioma causing dilatation of the intrahepatic bile ducts has been reported (51). Symptoms consist of abdominal pain and cholestasis. The imaging findings are those of a giant hemangioma associated with intrahepatic bile duct dilatation.
Compression of Portal Vein or Inferior Vena Cava.—Compression of hepatic vessels and especially the portal vein is an uncommon finding that has been described only in large hemangiomas (Fig 19).
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Percutaneous biopsy, including fine-needle aspiration biopsy,
has been described as both safe and effective (
,
). Although
not the optimal method of establishing the diagnosis, conventional
or fine-needle aspiration biopsy is especially helpful when
a
hemangioma
has an
atypical
morphology at imaging. Due to the
hypervascularity of the lesion, care should be taken when performing
the procedure and the needle should pass into the lesion via
the hepatic parenchyma.
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The differential diagnosis of atypical hemangiomas of the liver includes a large variety of hepatic tumors. In this section, the differential diagnoses of only the most frequent atypical hemangiomas are considered.
The differential diagnosis of hemangiomas with an echoic border includes all tumors surrounded by a hyperechoic rim. It is mainly represented by liver metastases, especially cystic islet cell tumors and liver adenomas. These two conditions may be detected in patients without symptoms or a history of malignancy. However, other imaging modalities such as CT or MR imaging will help differentiate hemangiomas from the other tumors.
The differential diagnosis of heterogeneous hemangiomas includes all hepatic tumors that have a scar, such as focal nodular hyperplasia, hepatocellular adenoma, hepatocellular carcinoma, and intrahepatic cholangiocarcinoma. MR imaging or scintigraphy is helpful for confirming the diagnosis of a large, heterogeneous hemangioma.
The differential diagnosis of rapidly filling hemangiomas includes all hepatic tumors that enhance during the arterial phase of contrast-enhanced imaging, including focal nodular hyperplasia, hepatocellular adenoma, hepatocellular carcinoma, and hypervascular metastases. The diagnosis of rapidly filling hemangioma is based on enhancement similar to that of the aorta, persistent enhancement on delayed scans, and MR imaging findings.
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Although atypical hemangiomas are rare, many radiologists will encounter atypical findings due to the high prevalence of hepatic hemangiomas. In some cases, such as large heterogeneous hemangiomas, calcified hemangiomas, pedunculated hemangiomas, or hemangiomas developing in diffuse fatty liver, a specific diagnosis can be established with imaging, especially MR imaging. However, in other atypical cases, the diagnosis will remain uncertain at imaging, and these cases will require histopathologic examination.
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http://www.ajronline.org/cgi/content/full/180/1/135
AJR 2003; 180:135-141
© American Roentgen Ray Society
Pictorial essay |
Hepatic Hemangioma: Atypical Appearances on CT, MR Imaging, and Sonography
Hyun-Jung Jang1,2, Tae Kyoung Kim3, Hyo Keun Lim4, Sang Jae Park2, Jung Suk Sim1, Hyae Young Kim1 and Joo-Hyuk Lee1
1 Radiation Medicine Branch, Research Institute, National Cancer Center, 809 Madu 1-dong, Ilsan-gu, Goyang-si, Gyeonggi-do, 411-764, Korea.
2 Center for Liver Cancer, National Cancer Center Hospital, National Cancer Center, Gyeonggi-do, 411-764, Korea.
3 Department of Diagnostic Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap-dong, Songpa-gu, Seoul, 138-736, Korea.
4 Department of Radiology and Gastrointestinal Center, Sungkyunkwan University School of Medicine, Samsung Medical Center, 50 Ilwon-dong, Kangnam-gu, Seoul, 135-710, Korea.
Received April 25, 2002; accepted after revision July 2, 2002.
Address correspondence to H.-J. Jang.
Top
Introduction
Small Hypoattenuating Hemangioma
Hemangioma is the most common benign tumor of the liver. The classic diagnostic findings for hemangioma are as follows [1]: on unenhanced CT, hypoattenuation similar to that of vessels; on dynamic contrast-enhanced CT or MR imaging, peripheral globular enhancement and a centripetal fill-in pattern with the attenuation of enhancing areas identical to that of the aorta and blood pool; on T2- and heavily T2-weighted MR imaging, hyperintensity similar to that of cerebrospinal fluid; on sonography, homogeneous hyperechogenicity or hypo- or isoechogenicity with a hyperechoic rim; and on delayed phases of 99mTc RBC scanning, a defect in the early phases that shows prolonged and persistent filling-in. Because of advances in imaging technology, hemangiomas are being detected more frequently. We have encountered various atypical forms that may be difficult to recognize as hemangiomas on cross-sectional imaging. In this pictorial essay, we illustrate the varied appearances of hemangiomas that do not meet conventional criteria on various current imaging techniques and provide possible explanations for their atypical appearances.
Small Hypoattenuating Hemangioma
Small hemangiomas are detected more frequently with helical CT, whereas they are easily overlooked on conventional CT because they tend to be isoattenuating on late-phase images [2]. Due to earlier scanning, slowly enhancing hemangiomas have more chance to show persistent hypoattenuation, the incidence being up to 8-16% [2, 3]. In daily practice, the incidence of this form of hemangioma is even greater than previously reported, especially for small hemangiomas that may not show the classic rapid-fill-in pattern [2]. The reason for this reported lower incidence is likely that the atypical appearance of this type of hemangioma may have misled researchers into precluding the possibility of hemangioma in the first place.
Small hypoattenuating hemangiomas are particularly problematic in patients with underlying malignancy. If present, the "bright-dot" sign—tiny enhancing dots in the hemangioma that do not progress to the classic globular enhancement because of the small size of the lesion and the propensity for very slow fill-in—is helpful in diagnosing this type of hemangioma [2] (Fig. 1A,1B,1C,1D). However, a number of hemangiomas have no discernible enhancement (Fig. 2A). One pathologic correlative study suggested that hemangiomas with a slow fill-in pattern have relatively large vascular spaces and that those with rapid enhancement have small vascular spaces and a large interstitium [4]. Such a tendency has no relationship to the size of the tumor [4]. Therefore, hemangioma should be included in the differential diagnoses of small hypoattenuating lesions as well as hypervascular lesions. Contrast-enhanced gray-scale harmonic sonography, which has the capability of real-time dynamic assessment, could be of help in characterizing such a small hypoattenuating hemangioma seen on routine single-phase helical CT (Figs. 2B and 2C).
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Atypical Signal on T2-Weighted MR Imaging
A long T2 relaxation time has been attributed to the presence of slowly flowing blood in the vascular spaces of the tumor, and this bright T2 signal on MR imaging is one of the most reliable findings in diagnosing hemangioma [5]. It has been reported that a threshold of 112 msec of T2 relaxation time results in 92% accuracy, 96% sensitivity, and 87% specificity for differentiating hemangiomas from metastases [5]. In small hemangiomas, marked hyperintensity on T2-weighted images is a particularly important finding because the pathognomonic nodular enhancement is frequently not present [3]. Rarely, hemangiomas with rapid enhancement (Fig. 3A,3B) or with unusual abnormalities (Fig. 4A) may show T2 signal intensity that is not as bright as cerebrospinal fluid on MR imaging and may cause confusion. The signal intensity characteristics are known to be related to the relative composition of vascular spaces and connective tissue in the lesion and to the presence of thrombosis, calcification, hemorrhage, or fibrosis [5].
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Attenuation Relative to Vascular Pool
Because enhancing areas in hemangioma consist of vascular spaces directly supplied by arteries, the attenuation of such areas is theoretically identical to that of the aorta on hepatic arterial phase and that of blood pool during later phase imaging. Such a characteristic is helpful in differentiating hemangiomas from other tumors, but occasionally this finding makes it difficult to distinguish hemangiomas from vessels on CT (Fig. 5). On the other hand, not rarely for hemangiomas in general, and more commonly in small hemangiomas, the enhancing areas show lower attenuation than that of the aorta or portal or hepatic veins on multiphase helical CT [3] (Figs. 4B and 6).
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Hemangioma Versus Hypervascular Malignancy
Differentiation of hemangiomas from other hypervascular tumors can be a challenge because some hypervascular tumors can mimic peripheral globular enhancement (Fig. 7A,7B,7C), and not all hemangiomas show such a characteristic pattern [3, 5]. Neuroendocrine tumors or metastases from breast or colon cancer may show strong T2 hyperintensity [5], and prolonged contrast-enhancement may be seen in certain hypervascular malignancies [3]. It is helpful to know that hemangiomas can remain unenhanced, but once the areas enhance they do not diminish. Interpretation based on the combination of two or more imaging characteristics is required.
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Hemangioma with Arterioportal Shunt
An arterioportal shunt associated with a hepatic tumor is generally recognized to be most characteristic of malignant tumors. However, an arterioportal shunt sometimes is seen in hepatic hemangiomas on multiphase helical CT [6] (Fig. 8A,8B). Similar temporal peritumoral enhancement can be seen on dynamic MR images [7] (Fig. 9A,9B). These tumors tend to show rapid enhancement [6, 7]. One possible explanation for this finding is that a rapidly enhancing small hemangioma has hyperdynamic status with large arterial inflow, rapid tumoral enhancement, and consequently, large and rapid outflow, which seems to result in early opacification of the draining portal vein via shunt and peritumoral enhancement [7]. The finding to note is a wedge-shaped or irregularly shaped enhancement adjacent to the hemangioma—with or without early visualized portal branches—during the hepatic arterial phase (Fig. 8A,8B) that becomes isoattenuating or slightly hyperattenuating relative to the normal liver during the portal venous phase [6]. An association with arterioportal shunt does not necessarily imply that the underlying tumor is malignant.
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Severe fatty liver may alter the apparent enhancement pattern of focal hepatic lesions. Even hypovascular tumors such as metastases can show relatively high attenuation on CT and may mimic hemangiomas with a persistent enhancement pattern (Fig. 10A,10B). In severe fatty liver, the attenuation of hemangioma may reverse to even hyperattenuation, although not greater than that of vessels, on unenhanced CT. Hemangiomas may also be accompanied by a focal spared zone as seen in malignant tumors in fatty liver. On sonography, this finding could create confusion with the hypoechoic halo seen in malignant tumors (Fig. 11A,11B,11C), contrary to hemangiomas' usual hyperechogenicity or hyperechoic rim. This unusual finding often makes subsequent CT or MR imaging necessary. Hemangiomas in fatty liver could produce a peculiar halo on CT or MR imaging as well, but in most cases, accurate diagnosis can be made without difficulty because of the characteristic dynamic enhancement pattern of hemangiomas.
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With progressive cirrhosis, hemangiomas are likely to decrease in size and become more fibrotic (Fig. 12A,12B,12C) and difficult to diagnose radiologically and pathologically [8]. Conversely, hepatocellular carcinoma and dysplastic nodules often mimic hemangioma on sonography (Fig. 13A,13B) because of hyperechogenicity resulting from factors such as necrosis, fibrosis, fatty change, or sinusoid dilatation. In cirrhosis, any hyperechoic nodule should be considered a probable hepatocellular carcinoma until proven otherwise.
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A subset of hepatic hemangiomas does not show the classic findings on CT, MR imaging, and sonography that are well known to radiologists. Radiologists should be aware that some hepatic hemangiomas may have atypical features on cross-sectional imaging that correlate with their varied hemodynamic and pathologic findings.
- Gore RM, Levine MS. Textbook of gastrointestinal radiology, 2nd ed. Philadelphia: Saunders, 2000: 1487-1497
- Jang H-J, Choi BI, Kim TK, et al. Atypical small hemangiomas of the liver: "bright dot" sign at two-phase spiral CT. Radiology 1998;208:543 -548[Abstract/Free Full Text]
- Kim T, Federle MP, Baron RL, Peterson MS, Kawamori Y. Discrimination of small hepatic hemangiomas from hypervascular malignant tumors smaller than 3 cm with three-phase helical CT. Radiology 2001;219:699 -706[Abstract/Free Full Text]
- Yamashita Y, Ogata I, Urata J, Takahashi M. Cavernous hemangioma of the liver: pathologic correlation with dynamic CT findings. Radiology 1997;203:121 -125[Abstract/Free Full Text]
- Bennett GL, Petersein A, Mayo-Smith WW, Hahn PF, Schima W, Saini S. Addition of gadolinium chelates to heavily T2-weighted MR imaging: limited role in differentiating hepatic hemangiomas from metastases. AJR 2000;174:477 -485[Abstract/Free Full Text]
- Kim KW, Kim TK, Han JK, Kim AY, Lee HJ, Choi BI. Hepatic hemangiomas with arterioportal shunt: findings at two-phase CT. Radiology 2001;219:707 -711[Abstract/Free Full Text]
- Jeong M-G, Yu J-S, Kim KW. Hepatic cavernous hemangioma: temporal peritumoral enhancement during multiphase dynamic MR imaging. Radiology 2000;216:692 -697[Abstract/Free Full Text]
- Brancatelli G, Federle MP, Blachar A, Grazioli L. Hemangioma in the cirrhotic liver: diagnosis and natural history. Radiology 2001;219:69 -74[Abstract/Free Full Text]
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Спасибо,Марио,очень
Спасибо,Марио,очень интересный материал.Представлены 2 случая гемангиом(у пациента с опухолью желудка и у другого с циррозом),которые только на КТ доказано,что это гемангиома! А все остальные истинные "причудливые" гемангиомы на УЗИ точно поставила бы образование нуждающеся в КТ(учитывая,что даже Дпплера нет) Единственное утешение,что ЧТО-ТО,да нашла для дальнейшего дообследования.
Оффтоп: Ребята как Вы
Оффтоп: Ребята как Вы изучаете английский язык, способы, методики, со словарем, спецкурсы!!? Сам им владею плохо, выручают базовые слова, латынь. Поделитесь опытом пожалуйста.
спасибо Марио!
спасибо Марио!
О, крутая подборка :)
О, крутая подборка :)