Benign surface lesion of bone composed of spindle cells, cartilage, and bone
May be part of continuum from fibroosseous pseudotumor of digits to acquired osteochondroma
IMAGING
General Features
Imaging Recommendations
Radiographic Findings
CT Findings
MR Findings
DIFFERENTIAL DIAGNOSIS
PATHOLOGY
General Features
Staging, Grading, & Classification
Gross Pathologic & Surgical Features
Microscopic Features
CLINICAL ISSUES
Presentation
Demographics
Natural History & Prognosis
Treatment
DIAGNOSTIC CHECKLIST
Consider
Image Interpretation Pearls
Reporting Tips
Selected References
Yoshida A et al: Bizarre parosteal osteochondromatous proliferation. In Fletcher CDM et al: World Health Organization Classification of Tumours: Soft Tissue and Bone Tumours. 5th ed. IARC Press. 348-50, 2020
Gholamrezanezhad A et al: Peering beneath the surface: juxtacortical tumors of bone (part II). Clin Imaging. 50:113-22, 2018
Doganavsargil B et al: A bizarre parosteal osteochondromatous proliferation (Nora's lesion) of metatarsus, a histopathological and etiological puzzlement. Joint Bone Spine. 81(6):537-40, 2014
Kransdorf MJ et al: Extraskeletal osseous and cartilaginous lesions. In Kransdorf MJ et al: Imaging of Soft Tissue Tumors. 3rd ed. Lippincott Williams & Wilkins. 555-9, 2014
Rappaport A et al: Nora's lesion or bizarre parosteal osteochondromatous proliferation: a rare and relatively unknown entity. JBR-BTR. 97(2):100-2, 2014
Broehm CJ et al: Bizarre parosteal osteochondromatous proliferation: a new cytogenetic subgroup characterized by inversion of chromosome 7. Cancer Genet. 206(11):402-5, 2013
Mahajan S et al: "Nora lesion" - bizarre parosteal osteochondromatous proliferation. J Clin Orthop Trauma. 3(2):119-21, 2012
Weiss SW et al: Osseous soft tumors. In Weiss SW et al: Enzinger and Weiss' Soft Tissue Tumors. 5th ed. Elsevier. 1044-7, 2008
Endo M et al: Bizarre parosteal osteochondromatous proliferation with a t(1;17) translocation. Virchows Arch. 447(1):99-102, 2005
Benign surface lesion of bone composed of spindle cells, cartilage, and bone
May be part of continuum from fibroosseous pseudotumor of digits to acquired osteochondroma
IMAGING
General Features
Imaging Recommendations
Radiographic Findings
CT Findings
MR Findings
DIFFERENTIAL DIAGNOSIS
PATHOLOGY
General Features
Staging, Grading, & Classification
Gross Pathologic & Surgical Features
Microscopic Features
CLINICAL ISSUES
Presentation
Demographics
Natural History & Prognosis
Treatment
DIAGNOSTIC CHECKLIST
Consider
Image Interpretation Pearls
Reporting Tips
Selected References
Yoshida A et al: Bizarre parosteal osteochondromatous proliferation. In Fletcher CDM et al: World Health Organization Classification of Tumours: Soft Tissue and Bone Tumours. 5th ed. IARC Press. 348-50, 2020
Gholamrezanezhad A et al: Peering beneath the surface: juxtacortical tumors of bone (part II). Clin Imaging. 50:113-22, 2018
Doganavsargil B et al: A bizarre parosteal osteochondromatous proliferation (Nora's lesion) of metatarsus, a histopathological and etiological puzzlement. Joint Bone Spine. 81(6):537-40, 2014
Kransdorf MJ et al: Extraskeletal osseous and cartilaginous lesions. In Kransdorf MJ et al: Imaging of Soft Tissue Tumors. 3rd ed. Lippincott Williams & Wilkins. 555-9, 2014
Rappaport A et al: Nora's lesion or bizarre parosteal osteochondromatous proliferation: a rare and relatively unknown entity. JBR-BTR. 97(2):100-2, 2014
Broehm CJ et al: Bizarre parosteal osteochondromatous proliferation: a new cytogenetic subgroup characterized by inversion of chromosome 7. Cancer Genet. 206(11):402-5, 2013
Mahajan S et al: "Nora lesion" - bizarre parosteal osteochondromatous proliferation. J Clin Orthop Trauma. 3(2):119-21, 2012
Weiss SW et al: Osseous soft tumors. In Weiss SW et al: Enzinger and Weiss' Soft Tissue Tumors. 5th ed. Elsevier. 1044-7, 2008
Endo M et al: Bizarre parosteal osteochondromatous proliferation with a t(1;17) translocation. Virchows Arch. 447(1):99-102, 2005
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