# Case report: Robotically visualized and biopsy-confirmed peritoneal carcinomatosis as initial identification of metastatic prostate adenocarcinoma in a patient with a history of prostatic urethral lift

## TL;DR

A 72-year-old man with a history of prostate issues was found to have rare peritoneal cancer during a planned prostate surgery, highlighting the importance of thorough pre-surgery exams.

## Contribution

This case report presents a rare instance of peritoneal carcinomatosis identified during robotic prostatectomy in a patient with prior prostatic urethral lift.

## Key findings

- Peritoneal carcinomatosis was identified during robotically assisted laparoscopic radical prostatectomy.
- Biopsy confirmed metastatic prostate adenocarcinoma with a significant PSA response to triple therapy.
- Genetic testing showed no clinically significant mutations.

## Abstract

Peritoneal carcinomatosis is a particularly rare presentation of prostate cancer. Here we report a rare clinical case of surgically identified peritoneal carcinomatosis at the time of a planned robotic prostatectomy in a patient with a history of prostatic urethral lift procedure.

A 72-year-old man, with a history of urinary retention managed with tamsulosin, presented to his local urologist. Prostatic urethral lift procedures were performed for symptom management. After a definitive uptrend in his prostate-specific antigen (PSA) values, a biopsy was obtained, which demonstrated prostate adenocarcinoma. On presurgical multidisciplinary review, it was presumed that he had very high-risk localized prostate cancer. However, upon initiation of robotically assisted laparoscopic radical prostatectomy (RALP), he was noted to have numerous punctate white plaques on the peritoneum; biopsy of these lesions confirmed metastatic disease—for which the patient was starting on triple therapy per the PEACE-1 trial. The PSA level responded appropriately, decreasing from 16.8 to 0.08. Genetic testing was performed and returned negative for any clinically significant mutations.

Our patient, diagnosed with peritoneal carcinomatosis during a planned RALP, highlights the importance of vigilant laparoscopic exam prior to this prostatectomy. Multidisciplinary discussion is crucial for individualized and optimal treatment planning.