Metastatic primary neuroendocrine carcinoma of the genitourinary tract: A case report of an uncommon entity

PATIENT: Male, 59 FINAL DIAGNOSIS: Neuroendocrine carcinoma of urinary bladder SYMPTOMS: Dysuria • hematuria MEDICATION: – CLINICAL PROCEDURE: MRI • cystoscopy SPECIALTY: Urology • oncology OBJECTIVE: Rare disease BACKGROUND: Neuroendocrine carcinomas of the genitourinary tract are rare but distinct and important entities because they are very aggressive tumors and are usually advanced or metastatic at the time of diagnosis. A high index of suspicion must be held by the pathologist viewing the specimen, as it can easily be misdiagnosed as a high grade urothelial carcinoma. Specific, proven treatment algorithms have been formulated over the years for the latter, whilst neuroendocrine carcinomas of the genitourinary tract are rare and treatment regimes have not yet been proven to show a significant improvement in survival in the majority of cases, so accurate diagnosis is important. CASE REPORT: We report the case of a 59-year-old man who presented with a short history of dysuria and frank hematuria. Imaging and cystoscopy revealed a large exophytic mass in the base of the urinary bladder, which extended into the bladder neck. Metastatic deposits were already present in his liver and vertebrae. Histology revealed a neuroendocrine carcinoma. CONCLUSIONS: A comprehensive review of the existing literature regarding this rare but aggressive tumor is presented, including advances in classification, pathogenesis, and treatment.