[Squamous cell lesions of the urinary bladder].

BACKGROUND: Squamous cell carcinoma (SCC) and transitional carcinoma with squamous differentiation (SCC/TCC) are rare in western countries. Chronic inflammation and irritation of the urothelium are common risk factors for the development of SCC and TCC/SCC. Tumour biology of squamous cell cancer and precancerous squamous lesions is different from transitional cell cancer (TCC). Recent advances in molecular analysis of benign and malignant squamous cell lesions indicate that they are closely associated and might lead to improved bladder cancer subclassification in the future. AIM: At present, the clinical management and therapy of SCC remains challenging, as scientific evidence based on prospective clinical trials is not available. We performed an analysis of available literature on natural history, treatment, and prognosis of SCC, SCC/TCC and metaplastic lesions. Furthermore, recent findings in molecular cancer biology are discussed with a focus on their relevance for SCC carcinogenesis.