# Abdominal Wall Abscess Caused by Small Intestinal Penetration That Was Difficult to Distinguish from a Malignant Tumor: A Case Report

## TL;DR

A 70-year-old woman had an abdominal abscess caused by a fish bone that pierced her intestine, mimicking a tumor and requiring surgery.

## Contribution

This case highlights the rare complication of fish bone ingestion leading to an abscess that resembles a sarcoma.

## Key findings

- An abdominal wall abscess mimicking a sarcoma was caused by a fish bone penetrating the small intestine.
- Surgical intervention confirmed the abscess and ruled out malignancy.
- The patient recovered after partial small intestine resection and drainage.

## Abstract

Fish bone ingestion is common but rarely causes complications such as abdominal wall abscesses, which can mimic malignancies such as sarcomas on imaging. Abscesses require drainage and antibiotics, while sarcomas need wide excision. Therefore, the differentiation between abscesses and sarcomas is important and often requires multidisciplinary involvement.

A 70-year-old woman presented with anorexia and a painful abdominal mass. Laboratory tests showed inflammation but normal tumor marker concentrations. The abdominal wall mass was hard and poorly mobile. Ultrasound showed a heterogeneous, mosaic-like internal structure, and CT and positron emission tomography-CT findings strongly suggested a malignant tumor such as sarcoma. We performed surgery and confirmed the presence of an abdominal wall abscess with small intestinal penetration caused by an ingested fish bone. The small intestine was partially resected, and pathology showed no malignancy. The patient recovered well and was discharged on postoperative day 9. The final diagnosis was an abdominal wall abscess caused by an ingested fish bone that perforated the small intestine.

We present a rare case of an abdominal wall abscess caused by penetration of the small intestine by an ingested fish bone.