A biopsy of a pigmented plaque from the back of a 40-year-old man shows nests and single atypical melanocytes scattered upward through all levels of the epidermis, with invasion into the papillary dermis. This pattern of pagetoid spread is the histological hallmark of which melanoma subtype?

• A Lentigo maligna melanoma
• B Acral lentiginous melanoma
• C Superficial spreading melanoma ✓
• D Nodular melanoma

Explanation

Superficial spreading melanoma shows prominent pagetoid scatter, with atypical melanocytes migrating singly and in nests through the epidermis at all levels, resembling Paget disease of the breast. Lentigo maligna melanoma shows mainly basal atypia along a flattened atrophic epidermis with solar elastosis, and acral lentiginous shows a lentiginous basal proliferation, so neither features full-thickness pagetoid spread as its hallmark.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.