Which microscopic pathologic findings are characteristic of squamous cell carcinoma of the urinary bladder?

Updated: Jun 11, 2019
  • Author: Muhammad T Idrees, MD; Chief Editor: Liang Cheng, MD  more...
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Answer

Answer

Microscopically, the tumors arise in the epithelium and infiltrate in sheets, nests, and islands (see the images below); they resemble epidermal tumors, with some combination of individual cell keratinization, keratin pearls, and intercellular bridges. Transurethral resection of bladder tumor (TURBT) biopsies may contain only keratinous debris. Keratinization of cells at the stromal interface is a sign of invasion.

Pathology of of urinary bladder squamous cell carc Pathology of of urinary bladder squamous cell carcinoma. This histologic image reveals deeply infiltrated, moderately differentiated squamous cell carcinoma of the bladder.
Pathology of of urinary bladder squamous cell carc Pathology of of urinary bladder squamous cell carcinoma.Note the infiltration into the muscularis propria by small nests and individual tumor cells.

The cells are polygonal with well-defined cell borders and have an amphophilic to eosinophilic cytoplasm. The nuclei are pleomorphic, occasionally bizarre, with irregular chromatin and prominent nucleoli. Mitotic figures are easily identifiable. Abundant degenerated cells are also seen in biopsy material. Squamous metaplasia has been seen in 17%-60% of nonendemic cases. (See the image below.)

Pathology of of urinary bladder squamous cell carc Pathology of of urinary bladder squamous cell carcinoma. This image shows squamous carcinoma in situ adjacent to the tumor.

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