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.
Adenomatoid Tumor/*diagnosis/pathology/surgery ; Calcium-Binding Protein, Vitamin D-Dependent/metabolism ; Hemangioma/*diagnosis/pathology/surgery ; Hepatectomy ; Humans ; Keratins/metabolism ; Liver Neoplasms/*diagnosis/pathology/surgery ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neprilysin/metabolism ; Tomography, X-Ray Computed ; Vimentin/metabolism

Adenocarcinoma ; pathology ; Adenomatoid Tumor ; metabolism ; pathology ; surgery ; Adenomyoma ; pathology ; Adult ; Antibodies, Monoclonal, Murine-Derived ; metabolism ; Biomarkers, Tumor ; metabolism ; Calbindin 2 ; metabolism ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Keratins ; metabolism ; Leiomyoma ; pathology ; Lymphatic Vessel Tumors ; metabolism ; pathology ; Middle Aged ; Uterine Neoplasms ; metabolism ; pathology ; surgery ; Young Adult