Small cell carcinoma of the ureter with squamous cell and transitional cell carcinomatous components associated with ureteral stone

We report a case of primary small cell carcinoma of the ureter with squamous cell and transitional cell carcinomatous components associated with ureteral stone, which is unique in that the patient has remained free of tumor recurrence for 36 months after the surgery without adjuvant chemotherapy or radiotherapy. A 60-yr-oid man presented himself with a right flank pain. Computed tomography revealed an ill-defined mass and a stone in the lower one third of the right ureter, and hydronephroureterosis above the stone-impacted site. The patient underwent right nephroureterectomy and stone removal. Upon gross examination, a 3.8 × 1.8 × 1.2 cm white and partly yellow mass was noted in the anterior part of the ureter, resulting in indentation of the ureteral lumen on the posterior side. Light microscopic examination revealed that the mass was mainly composed of small cell carcinoma, and partly squamous cell and transitional cell carcinomatous components. The overlying ureteral mucosa and renal pelvis also contained muitifocal dysplastic transitional epithelium and transitional cell carcinoma in situ. There was no vascular invasion, and the surgical margins were free of tumor. The small cell carcinomatous component was positive for chromogranin, neuron specific enolase, synaptophysin, and pancytokeratin but negative for high molecular-weight cytokeratin (K-903) by immunohistochemistry.