Squamous metaplasia with atypical repair
Sorry, that is
The correct diagnosis is:
Squamous cell carcinoma of the bladder
- Single and loosely clustered markedly atypical squamous cells are present together with atypical but degenerate transitional cells.
- Squamous cells have dense, eosinophilic cytoplasm and vary from bland benign appearing superficial squamous cells to cells with bizarre shapes and spindle forms. Nuclei are coarsely granular and irregular and nucleoli inconspicuous to prominent. Anucleated squames, keratin fragments, debris, blood and inflammatory cells are also present.
- The features are consistent with keratinizing squamous cell carcinoma. The cytology is beyond that expected in benign squamous metaplasia even with repair or condyloma change. A definitive diagnosis of squamous cell carcinoma requires histologic assessment. It is important to exclude invasion of previous squamous cell carcinoma arising from adjacent organs (penis, urethra, and lower female genital tract).
- Poorly differentiated squamous carcinomas may show only bizarre malignant cells with dense cytoplasm and raise a differential of sarcomatoid carcinoma or leiomyosarcoma.
- Cystectomy revealed an invasive keratinizing, well to moderately differentiated squamous cell carcinoma arising from the surface epithelium and raggedly invading the lamina propria and muscularis propria. Tumour cells had a classic squamous cell carcinoma appearance with abundant eosinophilic cytoplasm, keratohyaline granules and intercellular bridges. Transitional cell carcinoma was not identified. No evidence of schistosomiasis was noted.
- Transitional cell carcinoma with squamous differentiation is much more common than pure squamous cell carcinomas. Primary squamous cell carcinomas of the bladder comprise about 5% of bladder tumours (in non-bilharzial countries). Primary squamous cell carcinomas are assumed to arise in areas of squamous metaplasia. They are usually associated with chronic cystitis due to calculi, diverticulum, indwelling catheter, cyclophosphamide chemotherapy or schistosomiasis. In some regions endemic for schistosomiasis (the Middle East, southeast Asia, and South America), squamous cell carcinoma is the predominant bladder tumour.
- Squamous cell carcinomas of the bladder are usually fungating and/or ulcerative tumours and usually have invaded into muscularis propria at diagnosis and therefore have a poor prognosis.
BACK TO IMAGES
DeMay RM. The Art & Science of Cytopathology. Chicago: ASCP Press, 1996, 407.
Cotran RS, Kumar V, Robbins SL. Robbins Pathologic Basis of Disease, 5th edition. Philadelphia: W.B. Saunders Company, 1994, 1000.
Gray W, McKee GT. Diagnostic Cytopathology, 2nd edition. London: Churchill Livingstone, 2003, 492-3.