A 55-year-old patient has a pigmented lesion on the palm with irregular borders. Dermoscopy shows a parallel ridge pattern. This pattern is characteristic of:

• A Traumatic haematoma of the nail
• B Benign acral naevus
• C Acral lentiginous melanoma ✓
• D Kaposi sarcoma

Explanation

On dermoscopy of palmar/plantar surfaces, the parallel ridge pattern (pigmentation along the ridges — the elevated furrows of acral skin that contain eccrine duct openings) is the most specific dermoscopic feature of acral lentiginous melanoma (ALM) with approximately 90% sensitivity. Benign acral naevi show the parallel furrow pattern (pigmentation in the sulci/grooves). ALM is the most common melanoma subtype in Asians, Africans, and Hispanics, despite accounting for only ~5% globally.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.