Clinical Orthopaedics and Related Research®

, Volume 469, Issue 7, pp 2019–2027 | Cite as

Bizarre Parosteal Osteochondromatous Proliferation: A Locally Aggressive Benign Tumor

  • Jibu JosephEmail author
  • David Ritchie
  • Elaine MacDuff
  • Ashish Mahendra
Clinical Research



Bizarre parosteal osteochondromatous proliferation (BPOP) is a benign lesion of bone, and numerous questions remain unresolved regarding its etiology, diagnosis, and treatment.


We present the Scottish Bone Tumour Registry experience of this rare lesion.

Patients and Methods

We performed a retrospective analysis of the Scottish Bone Tumour Registry records. Histologic specimens were reexamined by a musculoskeletal pathologist. Radiographs were reevaluated by a musculoskeletal radiologist.


From 1983 to 2009, 13 cases (13 patients; six male, seven female) were identified. Their ages ranged from 13 to 65 years. All patients presented with localized swelling. Pain was present in five. Antecedent trauma was present in two. Nine lesions affected the hand, three the foot, and one the tibial tuberosity. Twelve lesions were excised and one was curetted. There were seven recurrences of which six were excised. One lesion recurred a second time and was excised. There were no metastases. Radiographs showed densely mineralized lesions contiguous with an uninvolved cortex. Cortical breakthrough was present in one case and scalloping in another. Histologic analysis characteristically showed hypercellular cartilage with pleomorphism and calcification/ossification without atypia, bone undergoing maturation, and a spindle cell stroma.


BPOP is a rare benign lesion that probably is neoplastic, with no gender predilection, and affecting patients over a wide age range. Previously trauma was considered an etiologic factor, but this no longer seems to be the case. The rate of recurrence was 50%, which may indicate a more extensive resection is required for this locally aggressive lesion. No metastases were reported. BPOP should not be mistaken for, or treated as, a malignant tumor.

Level of Evidence

Level IV, retrospective case series. See Guidelines for Authors for a complete description of levels of evidence.


Marginal Resection Tibial Tuberosity Recurrent Lesion Periosteal Reaction Myositis Ossificans 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We acknowledge the contribution to this study by Anand Pillai regarding collection of patient data.


  1. 1.
    Abramovici L, Steiner GC. Bizarre parosteal osteochondromatous proliferation (Nora’s lesion): a retrospective study of 12 cases, 2 arising in long bones. Hum Pathol. 2002;33:1205–1210.PubMedCrossRefGoogle Scholar
  2. 2.
    Boudova L, Michal M. Atypical decubital fibroplasia associated with bizarre parosteal osteochondromatous proliferation (Nora’s reaction). Pathol Res Pract. 1999;195:99–103; discussion 104.PubMedGoogle Scholar
  3. 3.
    Bush JB, Reith JD, Meyer MS. Bizarre parosteal osteochondromatous proliferation of the proximal humerus: case report. Skeletal Radiol. 2007;36:535–540.PubMedCrossRefGoogle Scholar
  4. 4.
    Dhondt E, Oudenhoven L, Khan S, Kroon HM, Hogendoorn PC, Nieborg A, Bloem JL, De Schepper A. Nora’s lesion: a distinct radiological entity? Skeletal Radiol. 2006;35:497–502.PubMedCrossRefGoogle Scholar
  5. 5.
    Dorfman HD, Czerniak B. Bone Tumors. St Louis, MO: Mosby; 1998.Google Scholar
  6. 6.
    Endo M, Hasegawa T, Tashiro T, Yamaguchi U, Morimoto Y, Nakatani F, Shimoda T. Bizarre parosteal osteochondromatous proliferation with a t(1;17) translocation. Virchows Arch. 2005;447:99–102.PubMedCrossRefGoogle Scholar
  7. 7.
    Flint JH, McKay PL. Bizarre parosteal osteochondromatous proliferation and periosteal chondroma: a comparative report and review of the literature. J Hand Surg Am. 2007;32:893–898.PubMedCrossRefGoogle Scholar
  8. 8.
    Gruber G, Giessauf C, Leithner A, Zacherl M, Clar H, Bodo K, Windhager R. Bizarre parosteal osteochondromatous proliferation (Nora lesion): a report of 3 cases and a review of the literature. Can J Surg. 2008;51:486–489.PubMedGoogle Scholar
  9. 9.
    Harty JA, Kelly P, Niall D, O’Keane JC, Stephens MM. Bizarre parosteal osteochondromatous proliferation (Nora’s lesion) of the sesamoid: a case report. Foot Ankle Int. 2000;21:408–412.PubMedGoogle Scholar
  10. 10.
    Helliwell TR, O’Connor MA, Ritchie DA, Feldberg L, Stilwell JH, Jane MJ. Bizarre parosteal osteochondromatous proliferation with cortical invasion. Skeletal Radiol. 2001;30:282–285.PubMedCrossRefGoogle Scholar
  11. 11.
    Horiguchi H, Sakane M, Matsui M, Wadano Y. Bizarre parosteal osteochondromatous proliferation (Nora’s lesion) of the foot. Pathol Int. 2001;51:816–823.PubMedCrossRefGoogle Scholar
  12. 12.
    Ly JQ, Bui-Mansfield LT, Taylor DC. Radiologic demonstration of temporal development of bizarre parosteal osteochondromatous proliferation. Clin Imaging. 2004;28:216–218.PubMedCrossRefGoogle Scholar
  13. 13.
    Meneses MF, Unni KK, Swee RG. Bizarre parosteal osteochondromatous proliferation of bone (Nora’s lesion). Am J Surg Pathol. 1993;17:691–697.PubMedCrossRefGoogle Scholar
  14. 14.
    Michelsen H, Abramovici L, Steiner G, Posner MA. Bizarre parosteal osteochondromatous proliferation (Nora’s lesion) in the hand. J Hand Surg Am. 2004;29:520–525.PubMedCrossRefGoogle Scholar
  15. 15.
    Nilsson M, Domanski HA, Mertens F, Mandahl N. Molecular cytogenetic characterization of recurrent translocation breakpoints in bizarre parosteal osteochondromatous proliferation (Nora’s lesion). Hum Pathol. 2004;35:1063–1069.PubMedCrossRefGoogle Scholar
  16. 16.
    Nora FE, Dahlin DC, Beabout JW. Bizarre parosteal osteochondromatous proliferations of the hands and feet. Am J Surg Pathol. 1983;7:245–250.PubMedCrossRefGoogle Scholar
  17. 17.
    Orui H, Ishikawa A, Tsuchiya T, Ogino T. Magnetic resonance imaging characteristics of bizarre parosteal osteochondromatous proliferation of the hand: a case report. J Hand Surg Am. 2002;27:1104–1108.PubMedCrossRefGoogle Scholar
  18. 18.
    Rybak LD, Abramovici L, Kenan S, Posner MA, Bonar F, Steiner GC. Cortico-medullary continuity in bizarre parosteal osteochondromatous proliferation mimicking osteochondroma on imaging. Skeletal Radiol. 2007;36:829–834.PubMedCrossRefGoogle Scholar
  19. 19.
    Shankly PE, Hill FJ, Sloan P, Thakker NS. Bizarre parosteal osteochondromatous proliferation in the anterior maxilla: report of a case. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1999;87:351–356.PubMedCrossRefGoogle Scholar
  20. 20.
    Smith NC, Ellis AM, McCarthy S, McNaught P. Bizarre parosteal osteochondromatous proliferation: a review of seven cases. Aust N Z J Surg. 1996;66:694–697.PubMedCrossRefGoogle Scholar
  21. 21.
    Soubeyrand M, De Pinieu G, Biau D, Anract P, Tomeno B. [Bizarre parosteal osteochondromatous proliferation (Nora’s lesion): two cases] [in French]. Rev Chir Orthop Reparatrice Appar Mot. 2007;93:494–500.PubMedGoogle Scholar
  22. 22.
    Sundaram M, Wang L, Rotman M, Howard R, Saboeiro AP. Florid reactive periostitis and bizarre parosteal osteochondromatous proliferation: pre-biopsy imaging evolution, treatment and outcome. Skeletal Radiol. 2001;30:192–198.PubMedCrossRefGoogle Scholar
  23. 23.
    Torreggiani WC, Munk PL, Al-Ismail K, O’Connell JX, Nicolaou S, Lee MJ, Masri BA. MR imaging features of bizarre parosteal osteochondromatous proliferation of bone (Nora’s lesion). Eur J Radiol. 2001;40:224–231.PubMedCrossRefGoogle Scholar
  24. 24.
    Vlychou M, Gibbons CL, Rigopoulou A, Ostlere SJ, Athanasou NA. Bizarre parosteal osteochondromatous proliferation of the clavicle. J Shoulder Elbow Surg. 2008;17:e18–e20.PubMedCrossRefGoogle Scholar
  25. 25.
    Yuen M, Friedman L, Orr W, Cockshott WP. Proliferative periosteal processes of phalanges: a unitary hypothesis. Skeletal Radiol. 1992;21:301–303.PubMedCrossRefGoogle Scholar
  26. 26.
    Zambrano E, Nose V, Perez-Atayde AR, Gebhardt M, Hresko MT, Kleinman P, Richkind KE, Kozakewich HP. Distinct chromosomal rearrangements in subungal (Dupuytren) exostosis and bizarre parosteal osteochondromatous proliferation (Nora lesion). Am J Surg Pathol. 2004;28:1033–1039.PubMedCrossRefGoogle Scholar

Copyright information

© The Association of Bone and Joint Surgeons® 2011

Authors and Affiliations

  • Jibu Joseph
    • 1
    Email author
  • David Ritchie
    • 2
  • Elaine MacDuff
    • 3
  • Ashish Mahendra
    • 4
  1. 1.Department of Trauma and OrthopaedicsGlasgow Western InfirmaryGlasgowUK
  2. 2.Department of RadiologyGlasgow Western InfirmaryGlasgowUK
  3. 3.Department of PathologyGlasgow Western InfirmaryGlasgowUK
  4. 4.Department of Trauma and Orthopaedic SurgeryGlasgow Royal InfirmaryGlasgowUK

Personalised recommendations