Age / Sex : 28 / M

Ossifying fibroma

Discussion

Findings:

A well-defined osteolytic lesion in the diaphysis of left proximal tibia.

A central located, well-defined mass with intermediate SI on T1- and T2WI
and diffuse enhancement on MRI

Differential
Diagnosis:

Adamantinoma, fibrous dysplasia

Diagnosis: 

Ossifying fibroma

Discussion:

Benign self limiting fibro-osseous lesion

Age : 1st or 2nd decade

Site

Proximal 2/3 of tibia(diaphysis), fibula, mandible, facial bone

Begin as intracortical extending into medullary cavity : cortical thinning

Eccenteric radiolucency (solitary or bubbly)

* Pathology: Benign fibro-osseous lesion composed of fibrous tissue with
woven bone formation

* Radiography: Osteolytic lesion with lobular loculations to a bubbly
appearance and circumscribed by a sclerotic border

* MRI:

-  Intermediate on T1-weighted
images and intermediate to high on T2-weighted images

-  Internal low-signal bands and multilocular
appearance

-  Diffuse contrast enhancement

* Differentiation from
adamantionma:

-  Moth-eaten border and complete medullary
involvement (adamantioma > ossifying fibroma)

References:

1. Jung JY, et al. MR findings of the osteofibrous dysplasia. Korean J
Radiol. 2014 Jan-Feb;15(1):114-22