Malignant renal epithelioid angiomyolipoma: A case report and review of the literature.

Malignant renal epithelioid angiomyolipoma (EAML) is rare, and currently there is no malignant criteria for its pathological diagnosis. In the present study, the case of a patient who suffered malignant renal EAML and underwent nephrectomy is reported. The histological patterns of the tumor were composed of sheets or nests of large polygonal epithelioid cells and thick-walled blood vessels, with clear mitoses. Immunohistochemistry demonstrated that the epithelioid and smooth muscle cells characteristically expressed human melanoma black-45, epithelial membrane antigen and actin. Pathological evaluation revealed malignant EAML with regional lymph node metastases. Magnetic resonance imaging and X-ray examination identified multiple liver and lung nodules at 16 months post-surgery. Since the patient did not respond to the initial treatment with doxorubicin and cisplatin, sorafenib was subsequently administered. However, the treatment was not effective, and the patient succumbed to multiple metastases six months later.