A 45-year-old male with alleged asymptomatic hepatic hemangioma of 4 years duration had right upper-quadrant pain and was referred to a tertiary hospital. Computed tomography and magnetic resonance imaging scans revealed a hypervascular mass of about 7 cm containing intratumoral multilobulated cysts. A preoperative liver biopsy was performed, but this failed to provide a definitive diagnosis. The patient underwent a partial hepatectomy of segments IV and VIII. The histologic findings revealed multifocal proliferation of flattened or cuboidal epithelioid cells and a highly vascular edematous stroma. Immunohistochemistry findings demonstrated that the epithelioid tumor cells were positive for cytokeratin (AE1/AE3), vimentin, calretinin, and cytokeratin 5/6, and were focally positive for CD10, and negative for WT1 and CD34, all of which support their mesothelial origin. Immunohistochemistry for a mesothelial marker should be performed for determining the presence of an adenomatoid tumor when benign epithelioid cells are seen.
展开▼
