A Rare Case of Advanced Urethral Diverticular Adenocarcinoma and a Review of Treatment Modalities

Female urethral diverticular cancer is a very rare entity with only around 100 cases reported so far in literature and accounts for <1% of all malignancies. In this article, we present a 47-year-old African American female with repeated hospital visits for urinary retention, hematuria, and urinary tract infections. Initial computed tomography imaging and cystoscopy was unremarkable except for a distended urinary bladder. Subsequent magnetic resonance imaging and corresponding cystoscopy eventually indicated the presence of a urethral diverticulum. She underwent urethral diverticulectomy and was found to have a mass arising from urethral diverticulum extending to vaginal walls. Her biopsy was suggestive of invasive adenocarcinoma in advanced stages, for which she subsequently underwent a total pelvic exenteration. Next-generation sequencing of the tumor showed CDKN2A/B loss, MSI-stable, and low TMB, thereby ruling out the options for targeted therapies. Extensive literature search and expert opinions were sought for her case since no consensus exists regarding the optimal therapeutic approach due to the rarity of this tumor. A final decision was made to treat her with platinum-based chemotherapy. Different treatment approaches including neoadjuvant chemoradiation followed by surgery, surgery followed by adjuvant chemotherapy, and surgery followed by chemoradiation have been tried. Platinum-based chemotherapy has generally been preferred based on an extensive literature search. Multimodality treatment approach seems to be the current approach to management for advanced stages for better overall survival. This case illustrates the challenges faced in making diagnosis and treatment decisions due to the rarity of this type of tumor and lack of consensus in the treatment approach.