[Prognostic significance of epidermoid metaplasia in urothelial carcinoma of the bladder].

A retrospective review of 186 cases of transitional cell carcinoma of the bladder observed between 1987 and 1990 is described. Squamous metaplasia was present in 37 cases. This histological feature was especially found in association with poorly differentiated and invasive tumors: the presence of extensive areas of squamous metaplasia (metaplastic areas = or > 50% of neoplastic surface) was always found in association with high grade neoplasms. For these reasons the authors conclude that transitional cell carcinoma of the bladder showing squamous metaplasia is more aggressive than pure transitional cell carcinoma.