MedGen

Melorheostosis (MEL) is characterized by 'flowing' hyperostosis of the cortex of tubular bones. The lesions are usually asymmetric and involve only 1 limb or correspond to a particular sclerotome. They may be accompanied by abnormalities of adjacent soft tissue, including joint contractures, sclerodermatous skin lesions, muscle atrophy, or hemangiomas (review by Hellemans et al., 2004). The designation combines root words meaning 'limb,' 'flow,' and 'bone.' Melorheostosis may sometimes be a feature of Buschke-Ollendorff syndrome (BOS; 166700), a benign disorder which is caused by mutation in the LEMD3 gene (607844). Although germline or somatic LEMD3 mutations had been postulated to cause isolated melorheostosis (Butkus et al., 1997; Debeer et al., 2003; Happle, 2004; Hellemans et al., 2004), several studies have not been able to prove this (Hellemans et al., 2004; Mumm et al., 2007; Zhang et al., 2009). [from OMIM]

A rare unclassified acute myeloid leukemia characterized by a proliferation of immature cells exclusively of the erythroid lineage without a significant myeloblastic component. Microscopically, the cells may be undifferentiated or proerythroblastic in appearance. Patients may present with pancytopenia with fatigue, infections, and mucocutaneous bleedings, as well as weight loss, fever, and night sweats. Prognosis is poor. [from ORDO]

Proliferation (excess production) of hemopoietically active tissue or of tissue which has embryonic hemopoietic potential. [from HPO]

Chronic myeloproliferative disease, unclassifiable is a hematological neoplasm characterized by clonal proliferation of myeloid precursors in the bone marrow, blood and other tissues (spleen, liver), with clinical, morphological and molecular features of myeloproliferative neoplasms (MPN), failing to meet criteria of a specific MPN. The presentation is nonspecific and variable and often includes leukocytosis, thrombocytosis and anemia. Splenomegaly, hepatomegaly as well as fatigue, malaise or weight loss may appear in advanced stages. [from ORDO]