Epithelioid angiomyolipoma (EAML) is a rare perivascular epithelioid cell tumor. It belongs to a subset of perivascular epithelioid cells neoplasms (PEComas) that are composed of a predominantly epithelioid cell component and an admixture of abnormal blood vessels and smooth muscle cells.
EAMLs occur infrequently and are typically discovered incidentally on routine imaging or while performing diagnostic procedures for other reasons. They are usually nonmalignant and affect less than one patient per 10,000 population.
The diagnosis of EAML is made on the basis of histologic findings and the presence of a high proportion of epithelioid cells with varying degrees of nuclear atypia and pleomorphic multinucleated cells in the tumor cytology. These cells are immunohistochemically positive for melanocytic markers and smooth muscle markers.
EAMLs are uncommon neoplasms and, unfortunately, they often develop metastatic spread. Consequently, their prognosis is poor.
A 53-year-old man was diagnosed with left renal EAML with multiple metastases in the greater omentum and liver. He underwent multiple treatment modalities, including surgical resection, arterial chemoembolization, liver lesion aspiration, and cryoablation with an argon-helium knife.
After successful treatment, the patient experienced a marked improvement of his overall health condition. The metastatic lesions subsequently disappeared, and the patient’s ascites was no longer present. This case suggests that PD-1 antibody nivolumab may be a viable therapeutic option for malignant epithelioid angiomyolipoma.
