Classification of Vascular Anomalies: An Update

Abstract

Vascular anomalies present both a diagnostic and therapeutic challenge to physicians. Identification of these lesions is difficult due to their immense phenotypic variability, and naming conventions for vascular anomalies have historically been inconsistent. Terms such as "hemangioma" are informative when used correctly, but can cause confusion and miscommunication if applied indiscriminately to all vascular anomalies. Accuracy in classification is essential, as both disease course and therapeutic options differ greatly depending on the particular vascular anomaly present. In order for clinicians to properly diagnose and treat patients with these diseases, a unified nomenclature must be employed. This section provides an update on the current classification of vascular anomalies, with clinical descriptions of the most commonly encountered lesions, and clarifies the ambiguous nomenclature present in the existing literature.

Keywords: classification; hemangioma; interventional radiology; malformation; vascular anomalies.

Fig. 1

Basic classification of vascular anomalies according to 2014 ISSVA guidelines. Vascular anomalies consist of proliferative vascular tumors and nonproliferative vascular malformations, which can be further subclassified based on malignant potential (tumors) or vascular channel(s) involved (malformations).

Fig. 2

Timeline describing growth and involution of congenital and infantile hemangiomas. Congenital hemangiomas develop prenatally, are fully formed at birth, and demonstrate rapid involution (RICH), partial involution followed by persistence (PICH), or noninvolution (NICH) thereafter. In contrast, infantile hemangiomas begin to grow weeks to months after birth, peaking in size around 1 year of age, and then gradually regress over several years. (Adapted from Mulliken JB, Enjolras O. Congenital hemangiomas and infantile hemangioma: missing links. J Am Acad Dermatol 2004;50(6):875–882.)

Fig. 3

Infantile hemangiomas. ( a ) Focal deep hemangioma with characteristic bluish color and nodular appearance (arrow). ( b ) Bright red plaque in “beard” distribution, consistent with superficial segmental hemangioma.

Fig. 4

Capillary malformations. ( a ) Glabellar nevus simplex demonstrating typical light pink coloration, indistinct borders, and midline location. Involvement of the nose and upper lip is less common. ( b ) Port-wine stains are generally darker, well-demarcated, located laterally on the face or body, and respect the midline.