A Review of Multiple Venous Malformations of the Upper Limb: Classification, Genetics, and Pathogenesis.

Venous (cavernous) malformations are commonly seen in the upper limb. There is no consensus in the literature regarding the classification of venous malformations. Patients may be viewed as 2 clinical entities: patients with single or multiple lesions. Single venous malformations are sporadic and nonsyndromic, whereas the presence of multiple malformations indicates the presence of either an inherited or an overgrowth (noninherited) disorder. In this article, the author reviews multiple venous malformations of the upper limb, offers a novel classification, and describes their clinical entities along with their genetics and pathogenesis. These clinical entities will also be described by categorizing the cases as per the clinical presentation. Furthermore, the number of cases seen by the author (during an experience of 28 years of practice in Saudi Arabia) in each category will be reviewed to give the reader an overall view of the frequency of presentation of each category to the hand/plastic surgery clinic. Clinically, patients may present in 4 different presentations depending on the distribution of the lesions: the late-onset malformations confined to the upper limb; malformations involving the limbs/face/trunk with no mucosal lesions; widespread malformations of the skin, oral mucosa, and the intestine; and venous malformations presenting as a well-known syndrome. The author has seen a total of 84 patients, and the most 2 common presentations were late-onset type (n = 26) and malformations involving the limbs/face/trunk with no mucosal lesions (n = 36). This is the most comprehensive review of multiple venous malformations of the upper limb.