# Case Report: Lumbar herniation of a low-grade appendiceal mucinous neoplasm mimicking a chronic abscess

## TL;DR

A rare case of a low-grade appendiceal tumor mimicking a chronic abscess is reported, emphasizing the need for accurate diagnosis to prevent peritoneal spread.

## Contribution

This case report highlights the diagnostic challenge of LAMNs presenting as chronic abscesses and underscores the importance of timely oncologic resection.

## Key findings

- A 53-year-old male presented with recurrent lumbar abscesses caused by a low-grade appendiceal mucinous neoplasm.
- Laparoscopic ileocecal resection and drainage led to complete recovery without pseudomyxoma peritonei or hernia recurrence.
- Staged hernia repair was planned due to active inflammation, avoiding mesh use.

## Abstract

Low-grade appendiceal mucinous neoplasms (LAMNs) are uncommon tumors that may lead to peritoneal dissemination if not completely excised, yet they often present with nonspecific symptoms. We describe a 53−year−old male with a three−year history of recurrent right lumbar “abscesses” whose contrast−enhanced CT suggested herniation of the ileocecal region into the abdominal wall. Laparoscopic exploration revealed a superior lumbar hernia containing an enlarged appendix with surrounding purulent fluid. The patient underwent laparoscopic ileocecal resection with side−to−side ileocolic anastomosis and drainage. Postoperative pathology confirmed a LAMN with surrounding suppurative changes and diverticular features in the right colon. No mesh repair was performed due to active inflammation; instead, staged hernia repair was planned. The patient recovered uneventfully, with no evidence of pseudomyxoma peritonei or hernia recurrence at follow−up. This case highlights the importance of considering appendiceal neoplasia in atypical hernias mimicking chronic abscesses, as timely recognition and complete oncologic resection are critical to prevent mucinous peritoneal spread and achieve optimal outcomes.