Hepatic Angiomyolipoma Mimicking Hepatocellular Carcinoma

Abstract

Hepatic angiomyolipoma (HAML) is a rare mesenchymal tumor of the liver with marked histological diversity. The present study was to review the magnetic resonance imaging (MRI) and clinical pathological features of HAML resembling hepatocellular carcinoma (HCC).Nine patients who underwent surgical resection and had pathological diagnosis of HAML were retrospectively analyzed.All of 9 patients (5 males and 4 females) had a solitary hepatic mass with a median size of 4 cm (from 1.4 cm to 15.3 cm). Seven cases were identified as incidental liver tumors during health screening and 2 patients were diagnosed for hepatic mass when visited hospitals with unspecific abdominal discomfort. Before resection, 6 cases were diagnosed as HCC on MRI. MRI on chemical shift imagings showed a large amount of lipids in 5 cases. The enhancement pattern of MRI was classified into 2 types: in 2 cases, lesions with small or no vessels that demonstrated prolonged enhancement (1 mixed subtype and 1 myomatous subtype) and in 7 cases, lesions with abundant central vessels that show rapid washout (3 mixed subtypes and 4 myomatous subtypes) in the portal venous/delayed phase. All patients underwent resection of hepatic tumor and no recurrence was observed during follow-up (range: 2–24 months) of median 10 months. By immunohistochemistry, the tumor cells demonstrated positive immunostaining for human melanoma black-45, smooth muscle actin, and CD34.In conclusion, all of 9 patients with HAML presented with none or nonspecific clinical manifestations. The diagnosis of HAML relies on disease and immunohistochemistry, but not MRI due to its resemblance to HCC.

Primary hepatic angiomyolipoma: immunohistochemistry and electron microscopic observations: a case report

“…Because the radiological features of HAML depend on the relative proportion of adipose cells in the tumor, HAML was not readily distinguishable from HCC [ 5 – 8 ]. Liver biopsy was helpful in the preoperative diagnosis of AML [ 9 ].…”

“…Recently, HAML lesions identified by focusing on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA MRI), immunohistochemistry, and both clinical and pathological characteristics of the tumors were reported [ 5 ]. However, to the best of our knowledge, there is no case report to date on the combination of Gd-EOB-DTPA MRI, immunohistochemistry, and electron microscopy.…”

Intrahepatic peribiliary perivascular epithelioid cell tumor (PEComa) associated with heterotopic pancreas: A case report

“…Diagnosis of PEComas is, however, problematic. In a previous study, 9 patients incidentally identified as having asymptomatic liver tumors were preoperatively diagnosed on the basis of MRI and their clinical features as 6 hepatocellular carcinomas, 2 adenocarcinomas, and 1 AML [8]. In the current case, the tumor was initially considered an intrahepatic cholangiocarcinoma because of an obstruction of the B2 bile duct and dilatation of its periphery.…”

The “Vessel through Strait” Sign is a Signature Radiological Sign for the Diagnosis of Left Hepatic Artery Variation

“…MRI scan was performed by a GE Signa HDx 1.5T scanner or a GE Signa HDx 3.0T scanner (both from GE Healthcare, Milwaukee, WI, USA). The scans followed the protocol for standard contrast-enhanced abdominal CT or MRI examination as previously described 8 9 10 . The slice thickness was 1.25 mm, 2.5 mm, 5 mm, and 7 mm, respectively, for determining the effects of slice thickness on the recognition of VTSS and was 5 mm for both CT and MRI in other analysis.…”