Background: Small cell carcinoma of the urinary bladder is a rare and highly aggressive tumor that has been described in case reports or small series. It accounts for <1% of all urinary bladder carcinomas. The prognosis of patients with small cell carcinoma of the urinary bladder is poor and depends on the
extend of the disease.
Case Report: Herein we report a case of a penile metastasis from small cell carcinoma of the urinary bladder. A 70-year-old man was treated for small cell carcinoma of the bladder with radical cystectomy and ileal conduit in 2007. Pathological examination of the radical sistoprostatectomy material revealed
an ulcerated, necrotic invasive undifferentiated tumor with bladder wall invasion. Left vesicula seminalis and prostatic tissue was also infi ltrated by the tumor cells. Small cell cancer of the urinary bladder was diagnosed. Adjuvant chemotherapy was planned but the patient did not accept it. Two months after the operation he has noticed a painful swelling on the right side of the penis. But he ignored it. Four months later he admitted to our clinic with a swollen, painful penis. Physical examination revealed a hard, ovoid nodule (3×3 cm in diameter) along the shaft of the penis near its base on the right side. Ultrasound revealed a 3×3 cm mass on the right side of the penis that not involved the corpus cavernosum. Pathology of the penile lesion revealed metastatic tumor. Morphological and immonohistochemical findings of the tumor cells were identical to the primary tumor cells.
Conclusions: Metastases to the penis are uncommon. Most penile metastases present with swollen and frequently tender penis, pain and/or priapism. In cases with bladder carcinoma which had metastasized to penis, the histopathologic type is mostly urothelial carcinoma. Small cell carcinoma of the bladder is uncommon and unlike urothelial carcinoma it behaves aggressively. And this is the fi rst case of small cell carcinoma of the bladder which has metastasized to the penis.

Keywords: Penile metastasis, small cell carcinoma