Cortical desmoids, also known as cortical avulsive injuries or the Bufkin lesion, are a benign self-limiting entity. This is a classic "do not touch" lesion, and should not be confused with an aggressive cortical/periosteal process (e.g. osteosarcoma).
Cortical desmoid is a misnomer as this lesion does not histologically correlate to true desmoid tumors.
It typically presents in adolescents (10-15 years of age). There may be a male predilection.
Patients are usually asymptomatic, and it is discovered incidentally. Occasionally pain may be present.
Cortical desmoids are classically seen at the posteromedial aspect of the distal femur. They can be bilateral in approximately one-third of cases.
Occasionally similar lesions have been described involving the humerus - medially at the insertion of the pectoralis major muscle or laterally at the insertion of the deltoid 9.
Typically shows a saucer-shaped radiolucent cortical irregularity involving the posteromedial aspect of the distal femoral metaphysis at the attachment of the adductor magnus tendon. The lesion lacks an outer margin.
Defines anatomy much better and is seen as a cortically based lesion in the expected location (i.e. posteromedial distal femoral metaphysis) 3,4:
- T1: low signal
- T2: high signal and surrounding low signal rim may be present
- T1 C+ (Gd): most show enhancement
On bone scan, there is an abnormal increase in activity because of the chronic stress/traumatic origin of this lesion.
Imaging differential considerations include:
- cortical desmoid is one of the skeletal “don’t touch” lesions
- 1. Geoffrey S. Goodin, Clinical Observations, PET/CT Characterization of Fibroosseous Defects in Children: 18F-FDG Uptake Can Mimic Metastatic Disease, AJR 2006; 187:1124-1128
- 2. Suh JS, Cho JH, Shin KH et-al. MR appearance of distal femoral cortical irregularity (cortical desmoid). J Comput Assist Tomogr. 20 (2): 328-32. J Comput Assist Tomogr (link) - Pubmed citation
- 3. Yamazaki T, Maruoka S, Takahashi S, Saito H, Takase K, Nakamura M, Sakamoto K. MR findings of avulsive cortical irregularity of the distal femur. (1995) Skeletal radiology. 24 (1): 43-6. Pubmed
- 4. Kontogeorgakos VA, Xenakis T, Papachristou D et-al. Cortical desmoid and the four clinical scenarios. Arch Orthop Trauma Surg. 2009;129 (6): 779-85. doi:10.1007/s00402-008-0687-6 - Pubmed citation
- 5. Gould CF, Ly JQ, Lattin GE et-al. Bone tumor mimics: avoiding misdiagnosis. Curr Probl Diagn Radiol. 36 (3): 124-41. doi:10.1067/j.cpradiol.2007.01.001 - Pubmed citation
- 6. Sklar DH, Phillips JJ, Lachman RS. Case report 683. Distal metaphyseal femoral defect (cortical desmoid; distal femoral cortical irregularity). Skeletal Radiol. 1991;20 (5): 394-6. - Pubmed citation
- 7. Tscholl PM, Biedert RM, Gal I. Cortical desmoids in adolescent top-level athletes. (2015) Acta radiologica open. 4 (5): 2058460115580878. doi:10.1177/2058460115580878 - Pubmed
- 8. Vieira RL, Bencardino JT, Rosenberg ZS, Nomikos G. MRI features of cortical desmoid in acute knee trauma. (2011) AJR. American journal of roentgenology. 196 (2): 424-8. doi:10.2214/AJR.10.4815 - Pubmed
- 9. Kay M, Counsel P, Wood D, Breidahl W. Cortical desmoid of the humerus: radiographic and MRI correlation. (2017) Skeletal radiology. 46 (7): 1011-1015. doi:10.1007/s00256-017-2638-1 - Pubmed