[Hepatic angiomyolipoma with variable histologic features: 8 cases resembling hepatocellular carcinoma or inflammatory pseudotumor].

BACKGROUND/AIMS: Hepatic angiomyolipoma (AML) is a rare mesenchymal tumor of the liver and demonstrates a marked histologic diversity. HMB-45 is a promising immunomarker for this tumor and especially helpful to diagnosis of some AMLs with unusual morphology. The purpose of this study was to better define the variable histologic feature of hepatic AML.

METHODS

Eight hepatic AMLs were examined, and all of that were resection specimens. The diagnosis was confirmed by the presence of HMB-45 positive cells. Median age was 41.5 years old, and mean size of tumor was 8.94 cm.

RESULTS

Conventional mixed type was 5 cases which showed myomatous, angiomatous and lipomatous component, and 3 cases were myomatous predominant. Variable patterns including spider web cell morphology, solid sheet-like and trabecular pattern were identified on myomatous component and variable amount and patterns of inflammatory cell infiltration was identified.

CONCLUSIONS

With only histologic features, it is difficult to distinguish hepatic AML from other hepatic tumor including hepatocellular carcinoma or inflammatory pseudotumor. A correct diagnosis of hepatic AML is possible by a close histologic examination with immunohistochemical stainings such as HMB-45 which is important to patient's prognosis.