# Dirty Mass sign of abdominal imaging: A case of silent pneumoperitoneum

## TL;DR

A rare case of retroperitoneal gas causing a 'Dirty Mass' sign is described, highlighting the importance of early detection in abdominal imaging.

## Contribution

This paper presents a clinical case emphasizing the significance of the 'Dirty Mass' sign in diagnosing retroperitoneal pneumoperitoneum.

## Key findings

- The 'Dirty Mass' sign on abdominal imaging indicates retroperitoneal gas.
- Early recognition of this sign can prevent complications in patients with retroperitoneal gas.
- Retroperitoneal gas is often caused by trauma or perforation of the gastrointestinal tract.

## Abstract

Pneumoperitoneum is a common complication after penetrating abdominal trauma, gastric ulcer, or colitis in which free air is present in the peritoneal or retroperitoneal space. Sole pneumoretroperitoneum, which refers to gas in the retroperitoneal space, is a rare entity, and when significant, results in a characteristic radiographic sign known as “Dirty Mass.” Common causes include penetrating trauma or perforation of the retroperitoneal portions of the gastrointestinal tract (duodenum, ascending colon, descending colon, and rectum). Our case describes a 59-year-old female admitted for sudden onset RLQ abdominal pain with Dirty Mass sign on abdominal KUB. Early recognition of these key radiographic findings accelerates management and reduces the risk of developing complications.