From OMIMCutaneomucosal venous malformation (VMCM) is an uncommon, heritable form of venous malformation in which lesions tend to be multifocal and small. They are composed of grossly dilated vascular spaces lined by a single continuous layer of endothelial cells, with areas of relative lack of surrounding mural cells, suggesting a defect in their recruitment. Some VMCM patients have venous malformations located in internal organs, and some have additional anomalies, including cardiac malformations (summary by Wouters et al., 2010).
Another form of autosomal dominant venous malformation, blue rubber bleb nevus (112200), is of uncertain relationship to VMCM. Multiple cerebrovenous anomalies without cutaneous lesions are also familial; see cerebral cavernous malformations (116860). Glomuvenous malformations (138000) are similar to but clinically distinguishable from VMCMs.
http://www.omim.org/entry/600195 From MedlinePlus GeneticsMultiple cutaneous and mucosal venous malformations (also known as VMCM) are bluish patches (lesions) on the skin (cutaneous) and the mucous membranes, such as the lining of the mouth and nose. These lesions represent areas where the underlying veins and other blood vessels did not develop properly (venous malformations). The lesions can be painful, especially when they extend from the skin into the muscles and joints, or when a calcium deposit forms within the lesion causing inflammation and swelling.
Most people with VMCM are born with at least one venous malformation. As affected individuals age, the lesions present from birth usually become larger and new lesions often appear. The size, number, and location of venous malformations vary among affected individuals, even among members of the same family.
https://medlineplus.gov/genetics/condition/multiple-cutaneous-and-mucosal-venous-malformations