UNDIFFERENTIATED SMALL-CELL CARCINOMA OF THE URINARY-BLADDER - REPORTOF 2 CASES WITH A PRIMARY URINARY CYTODIAGNOSIS

Two undifferentiated small-cell carcinomas of the urinary bladder are reported. The patients, 68- and 55-yr-old men, respectively, presented with painless hematuria. in the first case, numerous small, lymphocyt e-like cells with coarse chromatin, sometimes with small nucleoli, and high nuclear/cytoplasmatic ratios were found in cytologic urine speci mens. A cytodiagnosis of undifferentiated small-cell cancer was made. In the second case, urine samples showed rare aggregates of small, und ifferentiated cells in association with malignant urothelial cells. Th e cytodiagnosis of mixed tumor composed of undifferentiated small cell and transitional carcinoma was confirmed by histologic examination. T he presence of focal reactivity with anti-chromogranin antibody and ne urosecretory granules via electron microscopy supports a neuroendocrin e differentiation for the small neoplastic cells. The patients died 13 and 8 mo after diagnosis, respectively. (C) 1995 Wiley-Liss, Inc.