Prostate Cancer Metastatic to the Peritoneum: A Road Less Traveled by a Common Malignancy.

A 70-year-old Indian male with a history of a Gleason 7 (3+4) prostate cancer presented with abdominal ascites. Imaging was remarkable for peritoneal carcinomatosis as well as possible metastases to the bladder and seminal vesicle. Given the atypical pattern of presentation, further investigation was performed with studies of the ascites fluid. Cytology from the ascites fluid returned consistent with malignant cells of prostatic origin. His treatment course included androgen deprivation therapy (ADT), docetaxel, abiraterone, and cabazitaxel. He had eventual progression and worsening of his disease and performance status and was transitioned to hospice. This case demonstrated the importance of pursuing a thorough diagnostic evaluation, when faced with a rare presentation of a common malignancy. Furthermore, it illustrated the challenges incurred when tailoring standard regimens to best address the needs of the whole patient and not simply their disease.