Primary glomus tumor of the liver.

Primary glomus tumors are extremely rare in the liver. To this date, only two cases of primary glomus tumors of the liver have been reported in the literature. This report is the third case of this specified tumor. The patient was a 50 year-old Iranian woman who presented with a history of epigastric pain and nausea. Abdominal computed tomography (CT) scan showed a huge hepatic mass that replaced the entire left lobe. Surgical biopsy showed that the specimen consisted of a vascular network confined by the proliferation of epithelioid cells with round-to-oval nuclei and eosinophilic cytoplasms. The cells expressed diffuse reactivity for vimentin, smooth muscle actin and CD34, whereas no reactivity was observed with carcinoembryonic antigen, synaptophysin, chromogranin, cytokeratin, and human melanoma black 45. We conclude that glomus tumors must be considered in the differential diagnosis of hepatic masses, with immunohistochemical staining for smooth muscle actin being a useful method to prove the diagnosis.