Fumarate hydratase-deficient renal cell carcinoma presenting as pelvicalyceal filling defect: an unusual presentation of a rare disease.

A 75-year-old man was referred to our urology service with painless haematuria. The delayed phase on a subsequent computed tomography (CT) abdomen and pelvis showed a filling defect in the left renal pelvicalyceal system, suspicious for a transitional cell carcinoma. The patient underwent ureteroscopic biopsy suggestive of a papillary neoplasia, before progressing to a laparoscopic radical left nephrouretectomy. Final histology revealed a fumarate hydratase-deficient renal cell carcinoma with clear margins. The patient was subsequently referred for genetic counselling.