# A Rare Case of Primary Posterior Abdominal Wall Muscle Hydatid Cyst With Thoracolumbar Spinal Extension

## TL;DR

This paper reports a rare case of a hydatid cyst in the abdominal wall that extended into the spine, highlighting its unique presentation and diagnostic considerations.

## Contribution

The paper adds hydatid cysts to the differential diagnosis of spinal canal masses with muscle involvement.

## Key findings

- A patient presented with a posterior abdominal wall mass that extended into the spinal canal.
- MRI showed multiple cystic lesions extending through the neural foramina into the spinal canal.
- Hydatid cysts should be considered in the differential diagnosis of spinal canal masses with muscle involvement.

## Abstract

Primary intramuscular hydatid cysts are uncommon due to the contractile nature of muscles and their lactic acid content. Hydatid cysts with spinal extension are sometimes seen with primary vertebral body involvement. Our patient presented with a slow-growing posterior abdominal wall mass, and upon magnetic resonance imaging (MRI), it was revealed to be several cystic lesions in the abdomen wall with extension through the neural foramina into the spinal canal. The key differentials for spinal canal masses with neural foraminal expansion and muscle involvement are peripheral nerve sheath tumors. Our case report adds hydatid cysts to the differentials for well-defined cysts with variable intensities on MRI.