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hereditary multiple exostoses (diaphyseal aclasis)
Hereditary disorder characterized by exostoses arising from bony cortex deforming the metaphyseal region of some long bones.
Pathology:
- primarily affects endochondral bone during growth
- formation of numerous cartilage-capped, benign bone tumors (osteocartilagenous exostoses or osteochondromas) often accompanied by skeletal deformities & short stature
- a small percentage of exostoses may undergo malignant transformation resulting in an osteosarcoma or chondrosarcoma
- osteochondromas can also occur as a sporadic event
Genetics:
1) genetically heterogeneous
1) inheritance: autosomal dominant
2) defects in EXT1, EXT2, EXT3
Clinical manifestations:
1) bilateral involvement, but not symmetric
2) ulna many be shortened, resulting in ulnar deviation of the hand
3) valgus deformities of ankle are common
4) mechanical interference in a joint may be only symptom
5) dwarfism may occur
Radiology: exostoses
Related
exostosis; hyperostosis; osteoma; osteoncus
Ollier's disease (enchondromatosis)
General
osteochondroma; osteocartilagenous exostosis; osteochondromatosis
dyschondroplasia
skeletal dysplasia
Database Correlations
OMIM correlations
References
- DeGowin & DeGowin's Diagnostic Examination, 6th edition,
RL DeGowin (ed), McGraw Hill, NY 1994, pg 623
- Harrison's Principles of Internal Medicine, 14th ed.
Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 2274