A 72-year-old woman has a slowly enlarging, irregular, tan-brown macule with notched borders on the left malar cheek, present for 15 years. She has severe solar elastosis. Biopsy shows atypical melanocytes confined to the basal layer of an atrophic epidermis with dermal solar degeneration. Diagnosis:

• A Superficial spreading melanoma
• B Lentigo maligna ✓
• C Pigmented actinic keratosis
• D Solar lentigo

Explanation

Lentigo maligna (Hutchinson melanotic freckle) is a melanoma in situ occurring on chronically sun-damaged skin of elderly patients, classically the face, with atypical melanocytes proliferating along a flattened basal layer. It becomes lentigo maligna melanoma once invasion occurs. Solar lentigo shows elongated rete ridges with basal hyperpigmentation but no cytologic atypia, which excludes option D.

Reference: Rook's Textbook of Dermatology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.