Primary small cell carcinoma of the bladder is very rare pathological entity, follows an aggressive course and carries poor prognosis. The literature carrying these articles are scarce and due to which it poses a diagnostic challenge to the radiologist and urologists. Herein, we present a case of small cell carcinoma of urinary bladder in a 75-year-old male patient initially reported as poorly differentiated urothelial carcinoma on transurethral resection of bladder tumor specimen to emphasize its rarity as well as the role of immunohistochemistry to differentiate between the two.

Small cell carcinoma, Bladder, Immunohistochemistry