Age / Sex : 15 / M

Chief complaint: knee pain

What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

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Courtesy: So Yeon  Lee, Sungkyunkwan University, Kangbuk Samsung Hospital

Osteofibrous dysplasia (Ossifying fibroma)

Discussion

Findings:

A well-defined osteolytic lesion with sclerotic rim and bubble-like appearance in the metaphysis of left proximal tibia, on radiographies.

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

Differential Diagnosis:

Adamantinoma, fibrous dysplasia

Diagnosis:  

Osteofibrous dysplasia (Ossifying fibroma)

Discussion:

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

* Location: Exclusively occur in the tibia and fibula

* Age: early childhood

* Radiography: Oosteolytic 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 (adamnatioma > osteofibrous dysplasia)

- Presence of intralesional fat (osteofibrous dysplasia > adamnatioma)

References:

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

2. Khanna M, et al. Osteofibrous dysplasia, osteofibrous dysplasia-like adamantinoma and adamantinoma: correlation of radiological imaging features with surgical histology and assessment of the use of radiology in contributing to needle biopsy diagnosis. Skeletal Radiol. 2008 Dec;37(12):1077-84