Other carcinomas
Squamous cell carcinoma

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 1 August 2016, last major update March 2015

Copyright: (c) 2003-2016,, Inc.

PubMed Search: Squamous cell carcinoma [title] bladder

Related topics: Basaloid, Verrucous
Cite this page: Squamous cell carcinoma (various). website. Accessed October 26th, 2016.
Definition / General
  • 5% of bladder tumors in US, 75% in Egypt / Sudan (in Egypt, bladder cancers are 1/3 of all cancers)
  • Mixed urothelial and squamous carcinomas are more common than pure squamous cell carcinomas
  • Recommended to diagnose as squamous cell carcinoma only if tumor is solely composed of squamous cell component, with no urothelial carcinoma component (eMedicine)
  • Most commonly lateral wall and trigone
Clinical Features
  • Arises in background of chronic cystitis with squamous metaplasia; also bladder exstrophy, neurogenic bladder, chronic infection, bladder stones, bladder diverticula, chronic indwelling catheters, prolonged cyclophosphamide treatment, Schistosoma haematobium infection in Egypt / Sudan
  • Also associated with smoking
  • Difficult to detect since arises insidiously; often gross hematuria, dysuria, nocturia, frequency, pain, bacteriuria
  • 2/3 of cases occur in females
  • De novo cases are usually diagnosed in sixth and seventh decades, but patients with obstructive and irritative symptoms are diagnosed earlier
  • 5 year survival is 37% if pT1/pT2 vs. 13% for pT3
  • Regional nodal metastasis in 10-25%, distant metastases to bone and lung
  • Poorer prognosis if advanced muscle invasive disease at presentation
Gross Description
  • Large, ulcerated, necrotic
  • Often involves areas other than bladder base
  • 80% involve muscular wall at diagnosis
  • Surface necrosis and keratin debris are usually present, giving it a flaky, whitish appearance
Gross Images
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Squamous cell carcinoma

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Cytoprostatectomy specimen

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Large tumor arising in the lateral wall of bladder

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Tumor appears sessile

Micro Description
  • Arises in epithelium, infiltrates in sheets, nests and islands
  • Resembles epidermal tumors with some combination of individual cell keratinization, keratin pearls and intercellular bridges
  • TURBT biopsies may contain only keratinous debris
  • Keratinization of cells at stromal interface is sign of invasion (per Murphy); cells are polygonal with well defined cell borders, amphophilic to eosinophilic cytoplasm
  • Nuclei are pleomorphic, occasionally bizarre, with irregular chromatin and prominent nucleoli
  • Mitotic figures are common, as are degenerated cells
  • Squamous metaplasia present in 17-60% of nonendemic cases
  • Grading is not reproducible
Micro Images
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Well-differentiated, higher mag

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Keratinizing squamous cell carcinoma

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Focal squamous differentiation

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Squamous differentiation with keratin pearls

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Tumor associated with Schistosomiasis

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In sarcomatoid urothelial component

Cytology Description
  • High index of suspicion needed for detection since many cells resemble squamous metaplasia
  • Polygonal, fiber-like or tadpole like cells with well defined cell borders, amphophilic or eosinophilic cytoplasm with occasional vacuoles, enlarged and slightly pleomorphic nuclei with irregular chromatin, prominent nucleoli (if present)
  • Poorly differentiated cells resemble any high grade neoplasm
Positive Stains
Molecular / Cytogenetics Description
  • 9p-
Differential Diagnosis
Additional References