Frequency |
10% of benign osseous tumors.88 Chun KA, Stephanie S, Choi JY, Nam JH, Suh JS. Enchondroma of the Foot. J Foot Ankle Surg 2015;54(05):836–839 The prevalence of Ollier disease is 1/100,000.11 Fisher TJ, Williams N, Morris L, Cundy PJ. Metachondromatosis: more than just multiple osteochondromas. J Child Orthop 2013;7 (06):455–464
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20–50% of all benign bone tumors and 10–15% of all bone tumors.77 Bowen ME, Boyden ED, Holm IA, et al. Loss-of-function mutations in PTPN11 cause metachondromatosis, but not Ollier disease or Maffucci syndrome. PLoS Genet 2011;7(04):e1002050 The prevalence of multiple osteochondromas is estimated to be 2/100,000.11 Fisher TJ, Williams N, Morris L, Cundy PJ. Metachondromatosis: more than just multiple osteochondromas. J Child Orthop 2013;7 (06):455–464
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< 1/1,000,000, < 30 cases described.22 McFarlane J, Knight T, Sinha A, Cole T, Kiely N, Freeman R. Exostoses, enchondromatosis and metachondromatosis; diagnosis and management. Acta Orthop Belg 2016;82(01):102–105
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Location |
Frequently found in the hands more than in the foot and ankle bones, particularly in the phalanges.11 Fisher TJ, Williams N, Morris L, Cundy PJ. Metachondromatosis: more than just multiple osteochondromas. J Child Orthop 2013;7 (06):455–464
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Proximal humerus, tibia, and distal femur.11 Fisher TJ, Williams N, Morris L, Cundy PJ. Metachondromatosis: more than just multiple osteochondromas. J Child Orthop 2013;7 (06):455–464
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Enchondroma-like lesions: Metaphyseal regions of the long bones and iliac crest Osteochondroma-like lesions are mainly distributed in the hands and feet.66 Pansuriya TC, Kroon HM, Bovée JV. Enchondromatosis: insights on the different subtypes. Int J Clin Exp Pathol 2010;3(06):557–569
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Genetics |
Does not follow a clear Mendelian transmission pattern |
HMO is an autosomal dominant inherited trait.77 Bowen ME, Boyden ED, Holm IA, et al. Loss-of-function mutations in PTPN11 cause metachondromatosis, but not Ollier disease or Maffucci syndrome. PLoS Genet 2011;7(04):e1002050 EXT-1 and EXT-2 mutation (exostosin protein; endoplasmic reticulum transmembrane glycosyltransferase necessary for the heparan sulfate synthesis and physeal growth) |
Autosomal dominant PTPN11 gene mutation, lack of tyrosine phosphatase SHP2 |
Radiology |
Formation of hyaline cartilage in the medulla of a bone.22 McFarlane J, Knight T, Sinha A, Cole T, Kiely N, Freeman R. Exostoses, enchondromatosis and metachondromatosis; diagnosis and management. Acta Orthop Belg 2016;82(01):102–105 Well-defined, expansile, lytic lesions with varying degrees of stippled or punctate calcifications in the diaphysis or metaphyseal-diaphyseal regions of the bone.11 Fisher TJ, Williams N, Morris L, Cundy PJ. Metachondromatosis: more than just multiple osteochondromas. J Child Orthop 2013;7 (06):455–464
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Cartilage pedunculated or sessile lumps outside the metaphyseal region of the long bones.22 McFarlane J, Knight T, Sinha A, Cole T, Kiely N, Freeman R. Exostoses, enchondromatosis and metachondromatosis; diagnosis and management. Acta Orthop Belg 2016;82(01):102–105
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Epiphyseal-pointing osteochondroma-like lesions combined with calcified enchondroma-like lesions (Figs. 1 and 2). They can spontaneously regress.33 Wittram C, Carty H. Metachondromatosis. Pediatr Radiol 1995;25 (Suppl 1):S138–S139
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Anatomopathological examination |
On gross visual inspection, an enchondroma will appear as a bluish, semitranslucent, hyaline cartilage with a distinctly lobular arrangement. These lobules will vary from a few millimeters to a few centimeters in diameter. Cytologically, an enchondroma will appear as small chondrocytes that lie in the lacunar spaces, with a small, round, regular nucleus, and no significant atypia. No mitoses will be seen. Occasional binucleate cells will be seen. Some enchondromas can contain foci of ossification within this cartilage11 Fisher TJ, Williams N, Morris L, Cundy PJ. Metachondromatosis: more than just multiple osteochondromas. J Child Orthop 2013;7 (06):455–464
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Bony lesion covered with a pearly-white smooth cap |
42% as osteochondromas, 33% as enchondromas, 17% combined.11 Fisher TJ, Williams N, Morris L, Cundy PJ. Metachondromatosis: more than just multiple osteochondromas. J Child Orthop 2013;7 (06):455–464
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Natural history |
New lesions do not appear after skeletal maturation |
New lesions do not appear after skeletal maturation |
New lesions do not appear after skeletal maturation |
Malignization |
5% in solitary enchondromas, >20% multiple enchondromatosis.11 Fisher TJ, Williams N, Morris L, Cundy PJ. Metachondromatosis: more than just multiple osteochondromas. J Child Orthop 2013;7 (06):455–464
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Between 0.4% and 2% in patients with solitary osteochondroma and between 1 and 4% in patients with HMO.77 Bowen ME, Boyden ED, Holm IA, et al. Loss-of-function mutations in PTPN11 cause metachondromatosis, but not Ollier disease or Maffucci syndrome. PLoS Genet 2011;7(04):e1002050
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No malignization |