Unicameral bone cyst

Case contributed by Matt Skalski


Shoulder pain and swelling.

Patient Data

Age: 3 years
Gender: Male

There is a solitary, unilocular, well-defined lucent lesion centrally located within the proximal humeral metaphysis which extends into the proximal diaphysis, occupying the entire diameter of the bone. The lesion is mildly expansile with mild cortical thinning. No periosteal reaction is evident. There are multiple lucent fracture lines extending through the lesion, with two small comminuted cortical fragments within the lesion , representing the "fallen fragment sign." There is minimal offset and no angulation of the distal humerus. 

Case Discussion

This lesion demonstrates typical radiographic characteristics of a simple/unicameral bone cyst with a pathological fracture demonstrating the diagnostic fallen fragment sign.   

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.