Primary hepatic clear cell myomelanocytic tumor. Case report and review of the literature.

A case of hepatic clear cell myomelanocytic tumor in a 31-year-old woman presenting clinically with abdominal pain is reported. Histopathologic examination showed a lesion characterized by a population of large epithelioid cells with clear or eosinophilic granular cytoplasm, rich in glycogen. Immunohistochemically, the tumor cells were positive for HMB-45, Melan-A and muscle-specific actin, but negative for epithelial markers, desmin, S-100 protein, and neuroendocrine markers. Ultrastructurally, the tumor cells had abundant glycogen, well-developed rough endoplasmic reticulum, microtubules and aberrant melanosomes. Clinical and pathologic features with a brief review of the relevant literature for hepatic CCMMT as a variant of perivascular epithelioid cell tumor (PEComa) are discussed.