Download 20130317175820_Pemphigoid

Microscopically, the lesion shows a subepidermal bulla or vesicle (i.e. the point of separation
is between the basal epidermis and the subjacent dermis). The epidermis thus forms the roof
of the blister and the papillary dermis forms its floor. The blister and the perivascular
infiltrate in the dermis often contain eosinophils. The edge of the bulla shows degranulating
eosinophils close to the basement membrane of the epidermis .
Histology: bullous pemphigoid, immunofluorescence for autoantibodies to epidermal
basement membrane, forming a bright (flourescent) green line along the epidermal basement
membrane
The acantholytic cleft was formed as a result of separation of basal cells from suprabasal cells and
from each other at the cell membranes. Hemidesmosomes were structurally normal. Separated
acantholytic cells retained “half” desmosomes, containing the intracytoplasmic dense plaque with
attached intermediate filaments, along the plasma membrane that abutted the cleavage plane.
These half desmosomes contained a finely flocculent material on their extracellular surface. These
residual half desmosomes were particularly prominent along the apical surfaces of basal cells and
tended to aggregate and coalesce. Individual intact desmosomes directly adjacent to acantholytic
areas appeared normal.