Irregular Blotch — SCE Dermatology MCQ

Correct answer: C — Irregular blotch — an asymmetrically placed structureless area of brown/dark pigmentation strongly associated with melanoma

An irregular blotch is a structureless area of dark-brown or black pigment occupying part of a melanocytic lesion in an asymmetric distribution. It represents confluent melanin in the epidermis and/or upper dermis without discernible structure. When asymmetrically placed and occupying >10% of the lesion, it is a melanoma-associated feature in the revised pattern analysis algorithm. A regular (symmetric) blotch centrally located is more consistent with a benign naevus. Irregular blotches, together with irregular network, irregular dots/globules, and blue-white veil, form the core melanoma-specific structures in dermoscopic assessment.

Reference: BAD 2016 Dermoscopy