SUPPLEMENTARY FILES: Mapping the Anatomic Distribution Patterns of Medium-to-Large Congenital Melanocytic Nevi on the Face
Description
Supplement A: Principles for differentiating between FCMN anatomic distribution categories. Supplement B: An extensive FCMN on the cheek, which crosses the nasolabial fold (left), is likely to have formed earlier during embryological development than an FCMN that does not cross the nasolabial fold (right). Supplement C: Similarly-sized horizontal (LC) vs. vertical cheek (LEyC) FCMN. Potential complications of treatment of FCMN 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 FCMN on the cheek (left) runs a higher risk of these complications. This problem is less likely to be encountered with horizontal flap movement for vertically-oriented nevi (right). Tissue expansion with either transposition or rotation flaps can minimize these risks. Supplement D: Medial forehead (MFN) vs. lateral forehead (LFT) FCMN. The risk for brow asymmetry that would require additional corrective surgery is higher for the laterally-located FCMN (case 2) than the medially-located FCMN (case 1). In contrast, the surgical scars for a large ‘LFT’ nevus of the lateral forehead can often be placed inconspicuously along the hairline, whereas reconstructive surgery of a large ‘MFN’ nevus located on the medial forehead will involve concealment of a centrally-located scar.