Hereditary Multiple Exostoses (HME) is a rare autosomal dominant skeletal disorder resulting from loss-of-function variants in the We aimed to comprehensively review the literature for reported cases Show more
Hereditary Multiple Exostoses (HME) is a rare autosomal dominant skeletal disorder resulting from loss-of-function variants in the We aimed to comprehensively review the literature for reported cases of non-skeletal malignancies in individuals with HME and evaluate a potential association with hematologic cancers, particularly in the pediatric population. An extensive literature search was conducted in the PubMed database up to August 2025 using search terms related to HME and malignancy. Eligible reports included case descriptions of non-skeletal cancers occurring in patients with confirmed or suspected HME. Extracted data included patient age, sex, cancer type, and available genetic or molecular findings. Thirteen cases of non-skeletal malignancies associated with HME were identified. Fewer than half underwent molecular genetic testing. Six cases occurred in pediatric patients, four of which involved hematologic malignancies, three leukemias and one Burkitt lymphoma. In adults, malignancies affected a range of organ systems, including respiratory, gastrointestinal, nervous, and endocrine. A marked male predominance was observed (11 males vs. 2 females). Although a definitive causal relationship cannot be established, hematologic malignancies in pediatric HME patients appear to be disproportionately represented among reported cases. This finding highlights the need for further investigation through large-scale, population-based studies incorporating both clinical and genetic data. Show less
Hereditary multiple osteochondromas (HMO) is an autosomal dominant disorder caused by heterozygous deleterious variants in the EXT1 or EXT2 genes. While the clinical core phenotype is well established Show more
Hereditary multiple osteochondromas (HMO) is an autosomal dominant disorder caused by heterozygous deleterious variants in the EXT1 or EXT2 genes. While the clinical core phenotype is well established and mainly consists of bone deformities, limb length discrepancies, multiple benign bone neoplasms, and increased risk of chondrosarcoma, the association of HMO with malignancies remains undefined. Only two cases have been reported to date. We report a third patient with HMO and leukemia. New research suggests that EXT1 and EXT2 genes may influence leukemogenesis through several mechanisms, including protein-protein interactions with leukemia-associated genes and modulation by specific microRNAs (miRNAs). Dysregulation of heparan sulfate biosynthesis, a pathway involving exostosin proteins, may disrupt the bone marrow microenvironment, impacting hematopoietic cell growth and differentiation. Show less