Glomuvenous malformations, also known as 'venous malformations with glomus cells' or glomangiomas, are similar to mucocutaneous venous malformations (VMCM; 600195), but clinically are distinguishable: they have a cobble-stone appearance, have a consistency harder than that of venous malformations, and are painful on palpation. Histologically, GVMs are distinguishable by the presence of pathognomonic rounded cells (glomus cells) around the distended vein-like channels. The term glomus (Latin for ball) stems from the morphologically similar contractile cells of the Sucquet-Hoyer arteriovenous anastomoses in glomus bodies that are involved in cutaneous thermoregulation. Glomus cells in GVMs appear to be incompletely or improperly differentiated vascular smooth muscle cells, since they stain positively with smooth muscle cell alpha-actin (102620) and vimentin (193060) (summary by Brouillard et al., 2002). The genetic distinctness of glomuvenous malformations from mucocutaneous venous malformations is indicated by the fact that mutations have been found in the TIE2/TEK gene (600221) in mucocutaneous venous malformations and not in glomuvenous malformations. [from
OMIM]