A biopsy is taken from the edge of a depigmented patch suspected to be vitiligo in a 24-year-old man, because pityriasis alba is a clinical consideration. Which histopathological finding confirms vitiligo?

• A Reduced melanin content with a normal number of melanocytes
• B Complete absence of melanocytes with DOPA-negative staining in the lesion ✓
• C Basal layer vacuolar degeneration with Civatte bodies
• D Dermal melanophages with solar elastosis in the papillary dermis

Explanation

Established vitiligo shows total loss of melanocytes from the epidermis, confirmed by DOPA negativity and absence of Melan-B or S-100 positive cells, along with loss of melanin. Pityriasis alba instead shows reduced melanin with a preserved normal complement of melanocytes, which is the discriminating fact. Vacuolar degeneration with Civatte bodies suggests lichen planus or lupus, and dermal melanophages with solar elastosis describe melasma histology.

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.