Acral Melanoma Dermoscopy — SCE Dermatology MCQ

Correct answer: C — The parallel ridge pattern (pigmentation following the ridges/sulci of dermatoglyphics) is the most specific dermoscopic pattern for acral melanoma

The parallel ridge pattern on acral dermoscopy is the single most specific dermoscopic indicator of acral melanoma — pigment is deposited along the sulci (ridges) of the dermatoglyphic pattern where eccrine ducts open. This contrasts with the parallel furrow pattern (pigment in the furrows between ridges) which is the most common BENIGN acral pattern. The distinction relies on identifying whether pigment follows ridges or furrows, aided by the position of eccrine duct openings (visible as white dots on dermoscopy — they sit on the ridges). Any acral lesion showing the parallel ridge pattern requires urgent biopsy. Acral melanoma is more common in darker-skinned individuals and has a poorer prognosis partly due to diagnostic delay.

Reference: BAD 2017 Melanoma; Acral Dermoscopy