Fine needle aspiration cytology of a recurrent malignant tumor of the kidney with rhabdoid features in an adult. A case report.

BACKGROUND: Malignant rhabdoid tumor of the kidney in children is considered a distinct entity. Malignant tumors with rhabdoid features in adults in extrarenal locations and in children over the age of 5 years are considered phenotypic variants. CASE: In a case of recurrent transitional cell carcinoma with rhabdoid features of the kidney in an adult, confirmed immunohistochemically and ultrastructurally, fine needle aspiration cytology showed discohesive, large- to medium-sized polygonal cells with eccentric nuclei; prominent nucleoli; abundant, pink cytoplasm; and paranuclear, eosinophilic density, corresponding to cytoplasmic eosinophilic globules seen in the histologic sections and cytoplasmic filamentous inclusions seen ultrastructurally.
CONCLUSION: The cytologic features of malignant rhabdoid tumors are characteristic.