NOF: typical presentation as an eccentric, multi-loculated subcortical lesion with a central lucency and a scalloped sclerotic margin.

NOF
-NOF is a benign well-defined, solitary lesion due to proliferation of fibrous tissue.
-It is the most common bone lesion.
-NOF is frequently a coincidental finding with or without a fracture.
-NOF usually has a sclerotic border and can be expansile.
-They regress spontaneously with gradual fill in.
-NOF may occur as a multifocal lesion. The radiographic appearance is almost always typical, and as such additional imaging and biopsy is not warranted.
Discriminators:
Must be under age 30.
No periostitis or pain.


http://www.radiologyassistant.nl/en/4bc6176e56228

Nonossifying fibroma/fibrous cortical defect. Left. AP radiograph image showing a fibrous cortical defect arising medially and a nonossifying fibroma arising laterally in the distal femoral metaphysis. Top right. Axial CT image showing a fibrous cortical defect arising medially and a nonossifying fibroma arising laterally in the distal femoral metaphysis. Middle right. Axial T1-weighted image showing a fibrous cortical defect arising medially and a nonossifying fibroma arising laterally in the distal femoral metaphysis. Bottom right. Axial T2-weighted fat-suppressed images showing a fibrous cortical defect arising medially and a nonossifying fibroma arising laterally in the distal femoral metaphysis. The CT confirms the cortical origin of both lesions and the low signal intensity on the MR images the predominantly fibrous nature of the matrix.
Non ossifying fibroma