Main histological types of BCa, incidence, characteristics

Histological typeIncidenceCharacteristics
Urothelial cancer90%The most common type, develops from the transitional epithelial cells lining the urinary bladder. It comes in non-invasive (NMIBCa) and invasive (MIBCa) forms. It is the predominant type in developed countries.
Squamous cell carcinoma3–5%Associated with chronic inflammation, most often caused by schistosome infection (especially in endemic regions) or chronic cystitis. It is characterized by an aggressive course.
Adenocarcinoma< 2%It arises from glandular cells; it may occur primarily in the bladder or be secondary (metastatic) from other locations. It is often associated with congenital defects such as persistent urachus.
Small cell carcinoma< 1%A very rare, highly aggressive type of cancer with a rapid progression, often with metastases at diagnosis. Histologically similar to small cell lung cancer.
Sarcoma< 1%Rare; originates from muscle tissue or other mesenchymal structures of the bladder. More common in children and young adults, known as rhabdomyosarcoma.
Mixed cancerVariableMay contain features of different types, e.g., urothelial and squamous. Mixed cancer shows a more aggressive course compared to pure urothelial tumors.

BCa: bladder cancer; MIBCa: muscle-invasive BCa; NMIBCa: non-muscle invasive BCa