Fine needle aspiration cytology diagnosis of renal medullary carcinoma: a case report.

Background: Renal medullary carcinoma is a recently described, highly aggressive neoplasm that affects predominantly young African American males with a history of sickle cell trait. To the best of our knowledge, this is the first report of fine needle aspirate cytology (FNAC) findings of renal medullary carcinoma.

Case: A 14-year-old, African American male with a history of sickle cell trait presented with the sudden onset of third cranial nerve palsy. Radiographic examination demonstrated possible tumor masses in the brain, thorax and left kidney. Ultrasound-guided fine needle aspiration was performed on the left kidney, and a cytologic diagnosis of "suspect renal medullary carcinoma" was rendered. The cytologic diagnosis was confirmed by tissue examination.

Conclusion: The cytologic features of renal medullary carcinoma include loosely cohesive clusters and single epithelioid cells with cytologic atypia, including high nuclear/cytoplasmic ratios, hyperchromasia, prominent nucleoli and cytoplasmic vacuolation. These cytologic findings, coupled with clinical findings (young black male with sickle cell trait), allow recognition of this rare renal neoplasm.