# Synovial chondromatosis of the distal radioulnar joint—a rare case

## TL;DR

A rare case of synovial chondromatosis in the wrist was misdiagnosed as a ganglion cyst, highlighting the need for careful differential diagnosis.

## Contribution

This case report adds to the limited literature on synovial chondromatosis of the distal radioulnar joint.

## Key findings

- The patient was diagnosed with synovial chondromatosis after initial suspicion of a ganglion cyst.
- Synovial chondromatosis is rare in the wrist and often misdiagnosed.
- Accurate diagnosis requires histological analysis and intraoperative findings.

## Abstract

Unclear wrist tumors are a common clinical presentation in patients with pain and movement restrictions of the wrist. We report a rare case of a benign tumor of the wrist in a 63-year-old female patient who presented with a ganglion-like swelling of the right hand. After examination and preoperative radiological diagnostics, the indication for an open surgery was indicated for resection of either a typical ganglion cyst or a peripheral nerve sheath tumor was made. Interestingly, the suspected diagnosis was not correct. The intraoperative finding and histological analysis revealed typical findings of synovial chondromatosis of the distal radioulnar joint. Although synovial chondromatosis is a relatively rare, and even rarer in the wrist, it is important to consider it as a differential diagnosis when a patient presents with a ‘simple’ wrist ganglion.