Table of Contents
Definition / general | Treatment | Case reports | Radiology description | Radiology images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosis | Additional referencesCite this page: Pernick N. Nonossifying fibroma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bonemetaphysealfibrousdefect.html. Accessed January 16th, 2021.
Definition / general
- Also called fibrous cortical defect
- Called nonossifying fibroma if loose, > 5 cm and associated with intramedullary component
- Distinctive lesions in teenagers, no gender preference
- Benign; asymptomatic except for possibly pain
- Probably a developmental defect (not neoplastic), usually resolves in a few years and is replaced by cortical bone
- Sites: usually metaphysis of distal femur, tibia; 50% are multiple; often < 1 cm
Treatment
- Usually none
- Curettage and bone grafts if large and at risk for pathologic fracture
Case reports
- 14 year old boy with tibial lesion and leg pain (Arch Pathol Lab Med 2000;124:917)
Radiology description
- Sharply demarcated radiolucencies surrounded by thin zone of sclerosis without a periosteal reaction
Radiology images
Gross description
- Red-brown, granular, well circumscribed
Microscopic (histologic) description
- Storiform pattern of fibroblasts with scattered benign giant cells, foamy histiocytes, cholesterol crystals, hemosiderin
- Mitotic figures common
- Rarely has bizarre (degenerative) nuclear features
- Resembles fibrous histiocytoma
Microscopic (histologic) images
Differential diagnosis
- Benign fibrous histiocytoma: painful, in pelvic and long bones, similar histology
- Giant cell tumor: older patients, usually epiphyseal, lytic, no sclerosis, diffuse giant cells with 40+ nuclei
Additional references