Multiple Hereditary Exostoses: Genetics, Multimodality Imaging Features, Complications, Differential Diagnosis, and Treatment

Abstract

Osteochondromas are a common type of benign bone tumor that occur during childhood. Osteochondromas can be solitary or multifocal as a part of a syndrome, known as multiple hereditary exostoses (MHE). This differentiation was first discovered in 1786 by John Hunter, a famous Scottish surgeon. In 1814, MHE was found to have a familial association. Later, in the 1900s, MHE was differentiated from other disorders, such as Ollier disease (multiple enchondromatosis) and Trevor disease (dysplasia epiphysealis hemimelica). MHE is known by other names including hereditary multiple osteochondromas, diaphyseal aclasis, hereditary deforming chondrodysplasia, and Ehrenfried disease. MHE occurs more frequently in males than in females (1.5–2:1) and whites. Males also tend to be more severely affected. In patients with MHE, the mean number of osteochondromas is typically 15 to 18. Osteochondromas typically occur within the first decade of life (80%) and continue to increase in size until physeal closure. Osteochondromas are most commonly asymptomatic, although they can present with various symptoms including pain and limb length discrepancies. Osteochondromas have key imaging characteristics that help to differentiate them from other types of skeletal lesions and to characterize malignant potential.1