The classification of vascular anomalies

Vascular malformations and vascular tumors are summarized collectively under the heading vascular anomalies and are rare diseases (orphan disease; prevalence less than 5 per 10,000 people). Diagnosis and therapy require interdisciplinary therapeutic approaches from an experienced team. Clinical appearance, pathophysiological considerations, genetic basis and imaging characteristics of vascular malformations and vascular tumors are manifold and sometimes overlap.

In the past, the relevant lesions were named by different medical subspecialties using different, sometimes overlapping, imprecise or even incorrect names. The following are typical examples: “peripheral vascular defects, angiomas, vascular malformations, AV angiomas, angiodysplasias, cavernous hemangiomas, vascular tumors, angiocavernomas, AV malformations, congenital vascular defects, vascular dysplasias”. In addition, numerous different lesions were grouped together as “hemangiomas” or “AV malformations”, even though they were based on a completely different vascular defect. The often incorrect designation as a “syndrome” (e.g., Klippel-Trénaunay, FP-Weber, Servelle-Martorell, Robertson, McCook, Hernandez, Parkes Weber syndrome) maintained the inconsistent nomenclature that led to confusion.

Arising from the preliminary work of Mulliken and Glowacki, the first classification of hemangiomas and vascular malformations, based on their endothelial characterization, was published in 1982. These principles were revised and further developed from 1992 onwards by an international team of experts, the “International Society for the Study of Vascular Anomalies” (ISSVA), so that today a much more comprehensive and accurate classification of vascular anomalies has been developed. The aim was to establish a uniform nomenclature that would provide a basis for the diagnostics and therapy of vascular anomalies for all disciplines involved in diagnosis and treatment. Correct diagnosis, designation and differential diagnosis are the basis for symptom and cause-oriented interdisciplinary treatment and care of patients with vascular anomalies.

In 2018, a fundamental update of the ISSVA classification of vascular anomalies took place, which has an undisputed importance in the classification of vascular malformations and vascular tumors.