Squamous Cell Carcinoma of the Bladder

Epidemiology:

• < 5% of bladder cancers
• Schistosoma haematobium infection (trematode worms)
• Live in the bloodstream of humans and animals
• S. mansoni and S. japonicum also infect humans
• Endemic regions:
• Egypt
• Sudan
• Some West African countries
1. Mali
2. Niger
• Some East and South-east African countries
1. Zimbabwe
2. Malawi
3. Tanzania
• Blacks >> Whites
• Tobacco smoking

Common sites:

Gross features:

• Bulky, often filling the bladder lumen
• Polypoid, fungating or ulcerative
• Necrotic
• Presence of necrotic material and keratin debris on the surface is relatively constant
• often cover large areas of bladder and deeply invasive when discovered
• almost never papillary

Histologic features:

• histologically pure squamous cell phenotype
• if an identifiable urothelial element including urothelial CIS is found, the tumour should be classified as urothelial carcinoma with squamous differentiation
• squamous metaplasia in the adjacent flat epithelium, especially if associated with dysplasia, supports a diagnosis of squamous cell carcinoma
• wide variation of differentiation
• keratohyaline pearls in well-differentiated
• marked nuclear pleomorphism and only focal evidence of squamous differentiation if poorly differentiated
• basaloid pattern has been reported
• almost never have true papillary patterns

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

Other features:

• nearly always associated with chronic bladder irritation and infection
• worse prognosis than high-grade urothelial CA
• 70% mortality in 1 year

References:

• ?Robbins
• Eble JN, Sauter G, Epstein JI, Sesterhenn IA. WHO Classification of Tumours: Pathology and Genetics of Tumours of the Urinary System and Male Genital Organs (2004)