Hereditary multiple exostoses: A case report and literature review

Abstract

Osteochondroma is the most common bone tumor representing 20%–50% of all benign bone tumors and 10%–15% of all bone tumors. Osteochondroma has similar radiological appearance in both solitary and multiple forms; the latter is an autosomal dominant disorder termed hereditary multiple exostoses. Associated complications of osteochondroma include deformity, fracture, neurovascular compromise, bursa formation, and malignant transformation. Measurement of the cartilage cap thickness is an important index suggesting secondary malignancy of osteochondroma. The upper limit of cap thickness after skeletal maturation is 1.5 cm which can be reliably measured on ultrasound or magnetic resonance imaging. Hereditary multiple exostoses are linked to the mutations of different exostoses genes located on chromosome 8, 11, and 19. We reported cases of two siblings presented with multiple osteochondromas managed by surgical excision. We evaluated their clinical and radiological presentation, genetic correlations and compared with the literature.

Treatment for ulnar shortening caused by osteochondromatosis

“…The surface of osteophytes is covered with cancellous bone caps of different thicknesses, with calci ed cartilage present. The tumor moves towards the shaft as the bone grows, and the growth direction is consistent with the direction of muscle traction, typically away from the joint [9] . The growth process of osteophytes is similar to that of normal bone, halting once growth stops.…”

Hereditary multiple exostoses with a giant osteochondroma degenerated into chondrosarcoma

“…Chondrosarcoma is a malignant tumor derived from cartilage-forming cells and is the most common malignancy associated with HME [ 6 , 8 ].…”

“…In the case reported the biopsy performed revealed a differentiated chondrosarcoma, which required a surgical excision: the exostosis at the bone base and the cartilage cap were removed. The prognosis depends on various factors, including the histologic grade of the tumor, the extent of the disease, and the adequacy of surgical resection [ 6 , 11 ].…”

“…Genetic testing that pinpoints the disease-causing mutation provides definitive confirmation. Fundamental is the pedigree of the patient's family members and the whole exome sequencing for genetic mutations of EXT1, EXT2, and EXT3 [ 5 , 6 ].…”

The most severe case of multiple osteochondromas in paleopathological record is from an Early Medieval burial site in the Venetian Lagoon

“…Evidence of single osteochondromas (Nicosia et al 2016; Varotto et al 2021) from Italian archaeological contexts is scarce and no cases of multiple osteochondromas are currently known. Moreover, MO is an incredibly rare example in the entire international palaeopathological record, with just 19 cases known from prehistoric to modern times worldwide.The case of MO presented in this study is not only the rst in Italy, but maybe the one with the most severe paleopathological expression globally, including degeneration into a malignant form (chondrosarcoma) of which a single example can be found in the archaeological record(Coughlan 2007) and comparable only to rare clinical cases today(Chilvers et al 2021;Ha et al 2022).…”