Radiology Teaching Files > Case 1012801

Contributed by: Virginia Mason Medical Center, Virginia Mason Medical Center, Washington, USA.
History: 33M with knee pain

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Findings: Well defined sclerotic focus posterior to the distal femur
Diagnosis: Tug lesion

Insertion of major muscles “tug” on periosteum and cortical bone causing a reactive fibrous lesion.

Lesions are 1 to 3 cm
Findings of focal cortical disruption, sclerosis, and thickening.

*Distal femur-medial(adductor longus) or posterior(gastrocnemius)
Humerus at the insertion of the pectoralis major

Confirmation with MRI demonstrating relationship of the muscle insertion to lesion.  
Biopsy is not indicated and may lead to false diagnosis of neoplasm.

Ddx Sclerosis + Periosteal Reaction:
Healing Fracture
Neoplasm: Metastasis, Lymphoma
Primary Bone Neoplasm: Osteoblastoma,Osteosarcoma, Ewing’s, Chondrosarcoma
Infantile Cortical Hyperostosis-multiple bones at different times. Usually long bones spared.
Melorheostosis-molten wax appearance

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Additional Details:

Case Number: 1012801Last Updated: 06-22-2006
Anatomy: Skeletal System   Pathology: Trauma
Modality: Conventional RadiographExam Date: 01-01-2000Access Level: Readable by all users

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