IMPORTANT: We currently have a number of bugs related to image cropping and are actively trying to resolve them. In the meantime, we have disabled cropping. Apologies for any inconvenience. Stay informed: radiopaedia.org/chat

Myositis ossificans

Case contributed by Chris O'Donnell
Diagnosis almost certain

Presentation

Painless enlarging lump in the anterior thigh. No history of recent trauma. Does play football.

Patient Data

Age: 17 years
Gender: Male

Suggestion by another...

mri

Suggestion by another reporting radiologist to exclude "sarcoma"

Despite the dense calcification on US and x-ray, the mass is T2 hyperintense with minor susceptibility artefact on the gradient echo sequence. The mass also enhances peripherally and is centered on the central tendon of the rectus femoris.

ultrasound

Markedly echogenic mass with shadowing indicative of calcification in the quadriceps muscle.  No associated non-calcified mass.

x-ray

Subtle but well-circumscribed calcification in the anterior thigh at the site of the patient's palpable swelling.

Case Discussion

This is an important diagnosis to make radiologically so as to avoid biopsy. It actually looks more "sinister" on MRI than X-ray or US. Keys to the diagnosis are the circumscribed calcification on X-ray, location that is prone to trauma in the anterior thigh, and intimate relationship to the rectus femoris tendon.

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.