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 May 23rd, 2018.
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
Missing Image

Squamous cell carcinoma

Missing Image

Cytoprostatectomy specimen

Missing Image

Large tumor arising in the lateral wall of bladder

Missing Image

Tumor appears sessile

Microscopic (histologic) 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
Microscopic (histologic) images
Missing Image


Missing Image

Well-differentiated, higher mag

Missing Image

Keratinizing squamous cell carcinoma

Missing Image

Focal squamous differentiation

Missing Image

Squamous differentiation with keratin pearls

Missing Image Missing Image

Tumor associated with Schistosomiasis

Missing Image

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