OSLAM syndrome is a rare autosomal dominant hereditary disorder. Its name is an initialism of "osteosarcoma, limb anomalies, and erythroid macrocytosis with megaloblastic marrow syndrome". OSLAM syndrome was recognised and described by Mulvilhill et al. as a syndrome that increases susceptibility to tumours and is characterised by an impaired regulation of bone and marrow development. Individuals with OSLAM syndrome have an elevated risk of bone cancer, limb abnormalities, and enlarged red blood cells.