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

Fibrous dysplasia

Case contributed by Bruno Di Muzio
Diagnosis certain

Presentation

Incidental finding after trauma.

Patient Data

Age: 40 years
Gender: Male

Right hand radiograph

x-ray

There is a central medullary geographic lytic lesion at the base of the fifth proximal phalanx measuring up to 12.7 x 9.1 mm (Long x trans), with predominantly sharp and non-sclerotic margins and some indistinct margins distally at the transition with the midshaft. There is a ground glass like appearance of the lesion matrix, but no chondroid or osteoid matrix. No bone expansion or cortical breach. No other lesions seen. Bones are otherwise normal. Joint spaces and alignment are preserved. No soft tissue abnormalities.

Case Discussion

The imaging features are those of a low aggressive lesion, and differentials would include enchondroma and fibrous dysplasia. 

The lesion was biopsied: Sections show three pieces of tissue comprised of immature woven bone with broad osteoid seams around central calcified areas, surrounded by fibrous tissue with a few osteoclasts and scattered small vessels. There is no inflammation or atypia. No cartilage is present. There is no evidence of malignancy.

DIAGNOSIS: Right little finger proximal phalanx biopsy: Fibrous dysplasia.

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.