Pleomorphic giant cell carcinoma of the urinary bladder: an extreme form of tumour de-differentiation.

AIMS: Vesical pleomorphic giant cell carcinoma (PGCC) is a variant of urothelial carcinoma (UC) characterized by highly pleomorphic tumour with giant cells. Fewer than 10 cases have been reported, and our aim was to determine the clinical and pathological features of a series of tumours from a specialized uropathology laboratory.

METHODS AND RESULTS: Thirteen cases of PGCC of the bladder were identified. There were nine males and four females, ranging in age from 53 to 92 years (mean 72 years). Associated conventional high-grade UC was seen in eight cases, while three cases also had micropapillary UC and one plasmacytoid UC. UC in situ (CIS) was present in five cases and occasional bizarre cells were seen in both UC and CIS. The proportion of PGCC present varied from 40% to 100% of tumour. Immunostaining performed on 10 cases showed uniform positivity for CK 8/18 and AE1/AE3, while most tumours were positive for CK7, CK20, uroplakin III and GATA binding protein 3 (GATA3). β-human chorionic gonadotrophin (β-hCG) was negative. Of 10 patients with follow-up, five died within 1 year and four are alive with tumour.

CONCLUSIONS: The association of PGCC with UC and an overlap in immunoexpression suggests that PGCC represents an extreme form of UC de-differentiation.