Venous malformations (VMs) are the most common sub-type of vascular malformation and consist of malformed veins that do not work properly. Venous malformations typically have slow and gradual enlargement. VMs may occur anywhere in the body including the skin, soft tissues, muscles and internal organs. VMs can be localized or diffuse, occur at more than one body site, and contain superficial veins, deep veins or a combination of both. A superficial VM will be maroon or purple in color, while a deep VM will be bluish in color. The color may change when compressed and the malformation my enlarge when the patient is crying, bearing down or being active. VMs may rapidly expand during pregnancy, puberty, menopause, post-trauma or surgery, when taking birth control pills, or during any.
Although the exact cause of these lesions is unknown, they are thought to be caused by errors in the formation and development of veins during fetal development. Some individuals with venous malformations have been found to have a genetic change in the TIE-2 gene. A deficiency of smooth muscle cells in the vein walls is known to be an important factor. VMs are not caused by any known drug, medication or environmental factor that the baby may have been exposed to during the pregnancy. Even though venous malformations are present at birth, they may not be identified until adolescence or even adulthood.
Glomuvenous malformations: These are inherited lesions that involve nerve cells and can be painful when touched. These malformations contain glomus cells that cause the lesion to be tense and non-compressible.
These lesions consist of multiple rubbery blue lesions on the skin that vary in size. These lesions are most commonly seen internally in the gastrointestinal tract, creating risk for severe bleeding and abdominal pain.