Case Eleven – November 2017

• 53 year old female presented with numerous flaccid blisters and erosions. Similar lesions were also present.

• Bullous pemphigoid
• Pemphigus vulgaris
• Erythema multiforme

Sections show an acantholytic dermatitis affecting suprabasilar keratinocytes. Retention of basal keratinocytes within the floor of the blister resulting in a characteristic “tombstone” pattern is seen.

Acantholysis involving the follicular epithelium is also present.

Pemphigus vulgaris

• Pemphigus vulgaris (PV) is the most common type of pemphigus
  • Other subtypes of pemphigus include pemphigus foliaceus, drug-induced pemphigus, fogo selvagem, and paraneoplastic pemphigus
• PV is an immunoblistering disease caused by autoantibodies to desmoglein 3, a component of desmosomes
• PV clinically presents as flaccid blisters and erosions with frequent involvement of the mucous membranes, including the oral cavity and genitalia
• Histopathology shows acantholysis of suprabasilar keratinocytes with adnexal involvement
  • Retention of the basal keratinocytes within the floor of the blister resulting in a “tombstone” pattern is frequently seen
  • Perivascular infiltration of eosinophils is also commonly present
• Direct immunofluorescence study shows staining within the epidermis for IgG and/or C3 in a net-like pattern
• The histologic differential diagnosis includes Darier’s disease and Hailey-Hailey disease
  • Darier’s disease shows more prominent acantholytic dyskeratosis with corp rounds and corp grains; DIF study is negative
  • Hailey-Hailey disease also shows acantholysis in a “dilapidated brick wall” pattern with the acantholysis sparing adnexal epithelium; DIF study is negative as well
• PV is usually well controlled using corticosteroids and immunosuppressive drugs such as rituximab

• PV is an immunoblistering disease caused by autoantibodies to desmoglein 3, a component of desmosomes
• PV clinically presents as flaccid blisters and erosions with frequent involvement of the mucous membranes, including the oral cavity and genitalia
• Histopathology shows acantholysis of suprabasilar keratinocytes with adnexal involvement and characteristic “tombstone” pattern at the base of the blister
• Direct immunofluorescence study shows staining within the epidermis for IgG and/or C3 in a net-like pattern
• The histologic differential diagnosis includes Darier’s disease and Hailey-Hailey disease