A case of invasive renal pelvic cancer: usefulness of auxiliary diagnosis using fluorescence in situ hybridization

A 65-year-old man, on whom transurethral resection had been performed twice for bladder cancer in the past, was admitted to our hospital for further Class V urinary cytology examination. A low density area of 1.5 cm in diameter in the left renal pelvis without enhancement was the only abnormal sign on computed tomographic (CT) imaging. Malignant cells were not detected by random biopsy of the urinary bladder. The retrograde pyelogram showed no filling defect on the left renal pelvis or ureter. The cytological diagnosis of the right split renal urine was Class III, and that of the left split renal urine was Class V. Fluorescence in situ hybridization (FISH) analysis, using specific probes for chromosome 8q21.3 and the centromere chromosome 11, was performed on cells from the bilateral split renal urine. Cells collected from the right split renal urine showed a normal disomic pattern, while those from the left split renal urine included an aneusomic pattern with polysomy. Left total nephroureterectomy was carried out. Histopathology proved invasive renal pelvic cancer. Thus FISH analysis may be useful for the localization of renal pelvic or ureteral cancers, which are difficult to diagnose.