Cytologic diagnosis of a primary pure oat cell carcinoma of the bladder in voided urine. A case report.
BACKGROUND
The urinary bladder is an uncommon site for primary oat cell carcinoma, with as few as 30 histologically diagnosed cases described in the literature. The first reported cytologic diagnosis was made in 1991.


METHODS
A 76-year-old female presented with gross hematuria. Voided urine cytology showed small, dark cells with little visible cytoplasm and coarse chromatin. Subsequent histopathologic, immunopathologic and electron microscopic studies confirmed the diagnosis of primary oat cell carcinoma.


CONCLUSIONS
The diagnosis of oat cell carcinoma is well recognized in respiratory cytology. The same cells found in a urinary specimen may suggest a primary oat cell tumor in conjunction with negative clinical and radiologic investigations for a primary tumor elsewhere.
McRae
S
S
Department of Pathology and Immunology, London Health Science Centre, Ontario, Canada.
Garcia
B M
BM
D000368:Aged; D002276:Carcinoid Tumor / Q000175:diagnosis; D002278:Carcinoma in Situ / Q000175:diagnosis; D018288:Carcinoma, Small Cell / Q000175:diagnosis* / Q000473:pathology* / Q000652:urine; D002295:Carcinoma, Transitional Cell / Q000175:diagnosis; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis; D008854:Microscopy, Electron; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000652:urine; D014556:Urine / Q000166:cytology*