# Primary Sternal Leiomyosarcoma

## TL;DR

A rare case of primary sternal leiomyosarcoma was discovered in a 70-year-old man during cancer staging and successfully treated with surgery.

## Contribution

This case highlights the rarity and unusual presentation of primary sternal leiomyosarcoma.

## Key findings

- Primary sternal leiomyosarcoma was diagnosed in a patient with no known primary tumor site.
- The tumor was successfully treated with sternotomy and reconstruction.
- Such tumors are extremely rare, accounting for less than 0.7% of all primary malignant bone tumors.

## Abstract

We report the case of a primary leiomyosarcoma of the sternum in a 70-year-old man that was discovered incidentally during prostate cancer staging with positron emission tomography combined with computed tomography. Interventional radiology biopsied the lesion; pathologic examination showed spindle cells, indicating probable leiomyosarcoma. No primary site was found on contrast computed tomography, thus suggesting that the tumor was primary rather than metastatic. Given the tumor’s location and mortality risk, the patient underwent a sternotomy and reconstruction with methyl methacrylate, followed by an uneventful recovery. This case underlines a rare leiomyosarcoma presentation, constituting less than 0.7% of all primary malignant bone tumors, noted for its unusual location and rarity.