A Rare Presentation of Metastatic Prostate Cancer With Recurrent Malignant Ascites: A Case Report and Literature Review.

Peritoneal carcinomatosis with malignant ascites is a rare and aggressive presentation of advanced prostate cancer, often linked to a poor prognosis. Here, a case of a 58-year-old African American male presenting with ascites as the initial manifestation of prostate cancer is reported. Imaging revealed peritoneal carcinomatosis with concomitant pelvic lymph nodes and bone metastases. Cytologic analysis of the ascitic fluid confirmed prostate origin. The patient underwent androgen deprivation therapy and systemic chemotherapy with docetaxel followed by cabazitaxel. Despite treatment, the disease progressed rapidly with rising prostate-specific antigen levels and recurrent ascites, and he ultimately passed away 15 months after diagnosis. A literature review of similar cases is included, highlighting the poor clinical outcome posed by this rare presentation. Currently, there are no standardized guidelines for managing malignant ascites in prostate cancer. This case underscores the importance of multidisciplinary care addressing both oncologic and social factors. Further research is warranted to elucidate the mechanisms of peritoneal dissemination, improve early detection, and develop tailored therapeutic strategies for prostate cancer presenting with malignant ascites.