SUPPLEMENTARY FILES: Mapping the Anatomic Distribution Patterns of Medium-to-Large Congenital Melanocytic Nevi on the Face: A Cross Sectional Study
Description
Summary: Distribution patterns of congenital melanocytic nevi have been characterized on the body, but not the face. Analysis of two independent image datasets of medium-to-large facial congenital nevi revealed nine distinct and nonrandom anatomic distribution patterns. Categorization of medium-to-large facial congenital nevi by distribution patterns may guide tailored management. Supplementary Figure 1: A) A CMN with a medial Frontonasal (MFN) distribution pattern, involving the medial forehead, glabella, and nasal root. B) A lateral CMN with a forehead/temple (LFT) distribution involving the lateral forehead and extending to the temple and eyebrow. Supplementary Figure 2: An extensive congenital melanocytic nevus (CMN) on the cheek, which crosses the nasolabial fold (left), may have formed earlier during embryonic development, prior to formation of the nasolabial fold, compared to a CMN that does not cross the nasolabial fold (right). Supplementary Figure 3: Similarly-sized horizontally-oriented (LC, left image) vs. vertically-oriented cheek (LEyC, right image) CMN on the cheek. Potential complications of treatment of CMN on the cheek include ectropion, nasal asymmetry, and contracture affecting the upper lip and commissure. Direct advancement of expanded or non-expanded flaps, in a vertical upward direction, to treat horizontally-oriented LC-category nevi on the cheek (left image) runs a higher risk of these complications. This problem is less likely to be encountered with horizontal flap movement for vertically-oriented LEyC-category nevi (right image). Tissue expansion with either transposition or rotation flaps can minimize these risks. Supplementary Table 1: Key features of the FCMN anatomic distribution categories. Supplementary Table 2: Principles for categorizing medium-to-large facial congenital melanocytic nevi to anatomic distribution categories.