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
- Mali
- Niger
- Some East and South-east African countries
- Zimbabwe
- Malawi
- 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:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
- nearly always associated with chronic bladder
irritation and infection
- worse prognosis than high-grade urothelial CA
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)