Pemphigus vulgaris is characterized by which histologic finding?

• A. Subepidermal blisters
• B. Intraepidermal edema
• C. Subcorneal separation
• D. Suprabasal acantholysis

Answer: (D)

Pemphigus vulgaris shows loss of keratinocyte adhesion within the epidermis due to autoantibodies against desmosomes. This leads to acantholysis that occurs just above the basal layer, creating an intraepidermal blister with the basal cells remaining attached to the basement membrane (the "tombstone" appearance). This suprabasal acantholysis is the hallmark histologic finding.

Other blistering patterns reflect different disease mechanisms: subepidermal blisters arise below the basement membrane (as in bullous pemphigoid), and separation at the subcorneal level can be seen in pemphigus foliaceus.