CLINICAL HISTORY
A 37-year-old previously healthy woman, presented with a five-month
history of weight loss anorexia, abdominal distention and discomfort.
The patient had no prior history of hepato-biliary disease or tuberous
sclerosis. Physical examination disclosed hepatomegaly with a liver span
equal to 20 cm (Figure 1 A). On palpation of the abdomen, there was a
renitent firm mass in the upper right quadrant mobile with respect to
the superficial planes and fixed with respect to the deep planes. Tumor
markers, including alpha-fetoprotein, carcinoembryonic antigen, and
carbohydrate antigen 19-9 were all within normal limits. Aspartate
aminotransferase, alanine aminotransferase and total bilirubin were
within the normal range. Contrast-enhanced computed tomography scan
demonstrated a hepatic mass located in segments IV, V and VI, with
exophytic development, moderate and heterogeneous arterial enhancement,
continuing in the portal and late stages, without detectable washout or
late capsular enhancement (Figures 1B & 1C). This mass measured 170 x
110 mm in the axial plane and 200 mm in height. It had a close vascular
contact with the right hepatic artery, the cystic artery, the right
portal branch as well as its segmental portal branches of IV and VI,
which remained permeable, without real invasion. Computed tomography
scan also disclosed a left ovarian mass measuring 90 x 60 x 90 mm
suggestive of teratoma (Figure 1C). On abdominal magnetic resonance
imaging (MRI), low intensity was observed on a T1-weighted image and
high intensity on a T2-weighted image. The patient underwent fine needle
biopsy of the hepatic mass and histopathological examination of the
biopsy specimen was suggestive of hepatocellular carcinoma. Right
hepatectomy was performed with informed consent of the patient.
Intraoperatively, a relatively soft dark red giant tumor was found to
occupy the whole right lobe of the liver (Figure 1D). We received a
hepatectomy specimen which weighed 1050 grams and measured after
formalin fixation 17 × 15.5 × 6.5 cm. Cut section showed a
well-circumscribed cystic mass measuring 16 cm in diameter with a
hemorrhagic appearance and focal grey white firm areas in the periphery
(Figure 2A). Histologically, the mass was composed of an admixture of
smooth muscle cells, adipose tissue, and blood vessels (Figure 2B).
Sheets of mature adipocytes were seen in some of the sections focally.
The tumor proliferation consisted of 100% of epithelioid cells arranged
in a trabecular pattern (Figure 2C) or in sheets. Extensive
extramedullary hematopoiesis was noted in several sections with
hematopoietic elements, including megakaryocytes as well as erythroid
and myeloid precursors (Figure 2D). The vascular component was abundant
and was composed of thick (Figure 2B) and thin-walled vessels with a
striking peliotic pattern in some areas (Figure 3A). The epithelioid
cells showed round nuclei, and abundant eosinophilic or clear cytoplasm
(Figure 3B). Brown melanin granules were focally found within the tumor
(Figure 3 C). Neither tumor necrosis nor mitotic figures were observed.
The nonneoplastic liver showed mild nonspecific mononuclear infiltration
in the portal tracts. Based on these microscopic findings, epithelioid
angoimyolipoma, epithelioid hemangioendothelioma, hepatocellular
carcinoma and hepatocellular adenoma were considered as differential
diagnoses and an immunohistochemical study was performed. HMB45 (Figure
3D), MelanA, Smooth Muscle Actin and Desmin showed diffuse strong
positive staining. However, the tumor cells showed negative staining for
anti-hepatocyte, and CD34. The postoperative course was uneventful, and
the patient was discharged on postoperative day 10. At present, she is
still being followed-up.