S6C14P8-1: On the left, the patterns are psoriasiform and the keratin layer is represented. On the right, the keratin layer is incomplete; the basal unit is hyperplastic in psoriasiform patterns. Beneath the denuded area, the epidermis is porous (defects are prominent among individual cells of the hyperplastic basal unit). Individual cells protrude along the denuded surface just to the right of the center of the field. The papillary dermis is widened and edematous (pemphigus foliaceus).

Clearly, the entire basal unit is affected in the region showing a loss of the keratin layer. The porous pattern reflects a degree of acantholysis which allows for widening of spaces among the keratinocytes, but is insufficient to produce a confluent defect (a bulla). The autoimmune process has affected the entire thickness of the epidermis.

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S6C14P8-2: Superficial pemphigus with changes involving the granular layer, the keratin layer and, focally, the cells of the superficial unit beneath the granular layer. In the latter location, many of the cells are dyskeratotic. The basal unit of the epidermis shows edema over the tip of the papilla; in the area of epidermal edema, lymphocytes and histiocytes intermingle among the keratinocytes ( pemphigus foliaceus). The superficial unit is thin and the basal unit is hyperplastic; the site of the defect might be characterized as intermediate.

S6C14P8-3 Clefts are present in the granular layer and the keratin layer. To the right, neutrophils have collected in the defect. Cells of the granular layer, in losing their attachments to one another, bulge into the defect. The affected cells have condensed, acidophilic cytoplasm. Lymphocytes and histiocytes have migrated into the edematous basal unit.

S6C14P8-4: Dyskeratosis in this example of superficial pemphigus (pemphigus foliaceus) is spectacular. The underlying basal unit is edematous (spongiosis). Neutrophils are present in the inflammatory infiltrates of the bulla (same case as S6C14P8-3).

S6C14P8-5: The patterns qualify as hypertrophic pemphigus foliaceus with hyperplasia of both the basal and the superficial units. There is hypergranulosis. Green arrows identify acantholytic cells at the tips of epidermal papillae along the surface. Red arrows identify areas of hypergranulosis along the surfaces of the pits among the papillae. There are defects among granular cells of the pits.

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