RARE CLEAR-CELL ADENOCARCINOMA ARISING IN THE MALE BULBOMEMBRANOUS URETHRA: SURGICAL RESECTION AND CHEMOTHERAPY OUTCOME

Abstract

Primary urethral adenocarcinoma in males is exceedingly rare; the clear-cell variant is especially uncommon and poses diagnostic and therapeutic challenges. We report a case of primary clear-cell adenocarcinoma of the bulbomembranous urethra (pT1, G2) with perineural invasion and early pulmonary metastases, managed by wide local excision with partial urethrectomy followed by systemic chemotherapy with documented radiologic response.

Case presentation: A 53-year-old man presented with progressive difficulty in passing urine and a perineal swelling. MRI pelvis (20/03/2025) identified an enhancing peri-urethral mass involving the ventral surface of the posterior penis and bulbomembranous urethra. He underwent wide excision of the tumour with part of the urethra and urethroplasty on 25/03/2025. Histopathology (25/03/2025) revealed an invasive adenocarcinoma with clear-cell features involving the bulbomembranous urethra (tumour size ~4.5 × 4.5 × 4.2 cm). Immunohistochemistry showed strong CK7 positivity, focal CK20 positivity, AMACR positivity, focal PAX8 and Napsin positivity; Ki-67 ~70%. Pathologic stage was reported as pT1, grade G2 (moderately differentiated) with perineural invasion. A whole-body 18F-FDG PET-CT (07/05/2025) demonstrated FDG-avid pulmonary nodules consistent with metastatic disease. The patient received systemic chemotherapy (cisplatin + gemcitabine) from June 2025 (6-cycle plan). A follow-up contrast CT thorax-abdomen-pelvis on 02/09/2025 documented “no obvious residual or metastatic lesions in the present study”. The patient remains under oncologic surveillance.

Conclusion: Clear-cell adenocarcinoma of the male urethra is rare and may present with obstructive urinary symptoms. Diagnosis rests on histopathology and immunoprofile. Multimodal management — surgical resection of the primary combined with systemic chemotherapy for metastatic disease — can produce meaningful radiologic response and disease control in selected patients. Awareness of this entity and close multidisciplinary coordination are essential for optimal outcomes.