Squamous Cell Carcinoma of the Urinary Bladder: Clinicopathological and Molecular Update

Urinary bladder cancer is one of the most prevalent cancers worldwide.Squamous Cell Carcinoma (SCC) is an uncommon subtype of urinary bladder carcinoma.It is a malignant epithelial neoplasm arising in the urinary bladder demonstrating a pure squamous cell phenotype. On histopathology it is considered when tumor is showing pure squamous morphology without any component of conventional urothelial carcinoma. The SCC is a histologically distinct form of cancer. It arises from the uncontrolled multiplication of cells showing particular cytological or tissue architectural characteristics of squamous cell differentiation, such as the presence of keratin, tonofilament bundles or desmosomes. Majority of bladder SCC are high grade, high stage tumors with most cancers having muscle invasion at the time of diagnosis while overall about 80% of bladder cancers are non-muscle invasive bladder cancer at diagnosis.COX-2 is markedly expressed in all SCCs. An increased COX-2 level induces the development of SCC of the bladder affecting many biological features of this tissue including apoptosis, cell adhesion, angiogenesis and invasiveness.TERT promoter mutations, commonly found in conventional urothelial carcinoma, are also highly prevalent in urinary bladder squamous cell carcinoma suggesting a common tumorgenesis and potential utility as a molecular urine-based-screening assay.This review summarizes the current features related to clinical , pathological, and molecular features of SCC of urinary bladder.