Abstract
Background : We report an extremely rare case of malignant epithelioid angiomyolipoma (EAML) focusing on the imprint cytology.
Case : The patient was a 48-year-old female without tuberous sclerosis, with no history of malignant melanoma. Imprint cytology of the resected right renal tumor showed large polygonal granular cells with pleomorphic swollen nuclei, prominent nucleoli, intranuclear inclusions, and occasional atypical mitotic figures. Necrotic cellular debris was found in the background. The EAML cells were immunocytochemically positive for HMB-45 and melan-A. Histologically, the tumor consisted of a solid growth of large-sized polygonal epithelioid cells with deeply eosinophilic cytoplasm. Immunohistochemically, the tumor cells were positive for melanocytic markers and α-smooth muscle actin, but not for S-100 protein or epithelial markers.
Conclusion : It is very important to distinguish EAML from renal cell carcinoma and malignant melanoma, because the treatment options and prognoses may vary. We suggest that a definitive diagnosis of EAML can be made by evaluating imprint cytology.
