# Incidentally Diagnosed Low-Grade Primary Peritoneal Serous Carcinoma Within the Umbilical Hernia Sac in a Male: A Report of an Extremely Rare Case and Review of the Literature

## TL;DR

A rare case of low-grade primary peritoneal serous carcinoma was found in a male during hernia surgery and successfully treated with surgery and chemotherapy.

## Contribution

This report highlights an extremely rare case of PPSC in a male and discusses its diagnosis and treatment.

## Key findings

- Low-grade PPSC was incidentally diagnosed in a male during umbilical hernia repair.
- The patient was successfully treated with tumor debulking and hyperthermic intraperitoneal chemotherapy.
- Long-term follow-up and letrozole treatment are planned for the patient.

## Abstract

Primary peritoneal serous carcinoma (PPSC) is a rare tumor that develops in the peritoneum. PPSC originates from embryonic nests of Müllerian cells in the peritoneum, which are also present in the epithelium of the ovary. This similarity explains the histopathological resemblance between PPSC and low-grade serous ovarian carcinoma. While PPSC primarily affects women, it is an extremely rare occurrence in males, and it is believed that the significant difference in diagnosis rates between males and females is due to the inhibition of Müllerian system growth by substances produced by male Sertoli cells. These substances are present at higher levels in males, which may prevent the development of Müllerian system-derived tumors in men. We describe a 65-year-old male patient who presented for elective bariatric surgery and umbilical hernia repair, and an incidental finding of low-grade PPSC was made based on hernia sac pathology. The patient underwent further management, including tumor debulking and hyperthermic intraperitoneal chemotherapy (HIPEC), with positive outcomes. Long-term follow-up and oral letrozole treatment are planned.