Blue rubber bleb nevus syndrome  is a rare disorder that consists mainly of abnormal blood vessels affecting the skin or internal organs – usually the gastrointestinal tract. The disease is characterized by the presence of fluid-filled blisters (blebs) as visible, circumscribed, chronic lesions (nevi). BRBNS is caused by somatic mutations in the TEK (TIE2) gene. It was described by William Bennett Bean in 1958. Presentation
BRBNS is a venous malformation, formerly, though incorrectly, thought to be related to the hemangioma. It sometimes causes serious bleeding. Lesions are most commonly found on the skin and in the small intestine and distal large bowel. The lesions can also be found in the central nervous system, liver, and muscles. It usually presents soon after birth or during early infancy. Causes
The cause of blue rubber bleb nevus syndrome is currently unknown. The syndrome is considered sporadic. A patient who is diagnosed with BRBNS likely has a family history of other multifocal venous malformations which are a symptom of the disease. Autosomal inheritance of BRBNS has been found in familial cases associated with chromosome 9p, but the majority of cases are sporadic. The disease correlates with an onset of GI complications. It is reported that GI bleeding is the most common cause of death in most cases. Diagnosis
Blue rubber bleb nevus syndrome is difficult to diagnose because of how rare the disease is. Diagnosis is usually based on the presence of cutaneous lesions with or without gastrointestinal bleeding and/or involvement of other organs.
Treatment is not required for those with skin spots, but some individuals with BRBNS may want treatment for cosmetic reasons or if the affected location causes discomfort or affects normal function. Incidence
Blue Rubber Bleb Nevus Syndrome affects males and females in equal numbers. According to a review of literature, 20% of patients with BRBNS were from the United States, 15% from Japan, 9% from Spain, 9% from Germany, 6% from China, and 6% from France; and a lower number of cases from other countries. This indicates that any race can be affected by BRBNS. See also
Bart syndrome
List of cutaneous conditions

References
Further reading
Bean WB (1958). Vascular spiders and related lesions of the skin. Springfield, Illinois: Charles C.Thomas. pp. 178–85. External links

Blue rubber bleb nevus; Bean syndrome at NIHs Office of Rare Diseases