S6C32P26-Epidermolysis Bullosa acquisita

S6C32P26-1: This example of a subepidermal bulla shows a ruptured subepidermal defect with a portion of the roof to the right; it overhangs the defect. The neighboring epidermis shows slight hyperkeratosis and acanthosis; the hyperplastic epidermis mostly shows the pattern of a hyperplastic superficial unit. On the left, away from the denuded area on the right, there are small defects at the dermal-epidermal interface. The papillary dermis is widened and edematous. On the left, inflammatory infiltrates are mild. On the right, perivascular infiltrates of lymphoid cells are more prominent (epidermolysis bullosa acquisita).

S6C32P26-2 (EBA): The defect is sub-epidermal. The roof has been partially stripped away. The papillary dermis is widened. It is fibrotic and edematous; it contains loose, band-lke infiltrates of lymphoid cells. On the left bordering the defect, the epidermis is hyperplastic.

Buttons below provide access to pictorials and to respective PARENT CHAPTERS.

S6C32P26-3: The superficial unit of the epidermis is hyperplastic and a basal unit is spottily, and poorly, represented. There are lytic defects at the dermal-epidermal interface. Some of the small clusters of basal keratinocytes in the defects show cytopathic changes with shrinkage of cells and some degree of pyknosis of nuclei. In the area adjacent to the blue arrows, keratinocytes, bordering the defect, show degenerative changes; there is no defined basal layer. The overlying epidermis shows irregular pigmentation. Dermal papillae are preserved, but fibrotic. The papillae bulge into the defects left by the loss of epidermal attachments. To the right, one island of squamous epithelium is entrapped in one of these crevices. The papillary dermis is widened and fibrotic. It contains loose infiltrates of lymphocytes and histiocytes. Dermal fibroblasts are activated ( epidermolysis bullosa acquisita; EBA).

S6C32P26-4: The patterns overlap with those of cicatricial pemphigoid, but the reacting cells in this example of EBA, particularly along the floor of the defect, are histiocytes rather than neutrophils. Dermal papillae are blunt, but preserved. The floor of the defect is covered by condensed fibrin (as in lesions of cicatricial pemphigoid). The papillary dermis is fibrotic. Connective cells are activated (nuclei are enlarged).

S6C32P26-5: This example of EBA shows a floor of a bulla that is relatively straight from side to side (the patterns of dermal papillae are partially preserved). The papillary dermis is widened and fibrotic; it is loosely cellular. There are scattered remnants of the roof of the bulla; in these remnants, the superficial unit is hyperplastic. Sweat glands are regularly spaced near the lower margin of the dermis.

S6C32P26-6: At higher magnification, the roof of the bulla is basically a hyperplastic superficial unit with partial preservation of a basal layer. The papillary dermis presents a straight surface with prominent, activated mesenchymal cells (fibroblasts). It is fibrotic, somewhat edematous, and richly vascularized. The fibrosing reaction extends into the upper portion of the reticular dermis. The point of attachment on the right represents the site of an acrosyringium.

S6C32P26-7: Activated mesenchymal cells (fibroblasts) are loosely, but regularly, spaced in the newly formed fibrous tissue along the floor of the defect. There also appears to be a well defined basement membrane along the floor of the defect. Neutrophils are not a significant component of the reaction. Focally, the basal layer of the epidermis is interrupted. Over this area, there is a whorl of keratinocytes; this arrangement of cells is common in regions in which basal keratinocytes focally have undergone lysis. The fibrous tissue of the dermal papillae is pale and delicately fibrous. The changes in this fibrous matrix could be the result of stromolysis.

S6C32P26-8: One margin of a bulla is represented. The epidermis is attached to the dermis on the left; in this area, the basal layer shows vacuolar changes. The epidermis forming the roof of the defect shows lysis of basal keratinocytes. The defect contains histiocytes and condensed fibrin. The fibrin is particularly dense on the right near the top of the field (EBA). Blue arrows identify a cluster of necrotic keratinocytes and a few histiocytes, some of which are pigmented.

 

CLICK TO GO TO NEXT PAGE IN SEQUENCE

SELECTED READING

BACK (spatial sequence)

CLICK TO GO UP ONE PAGE (to return to parent textual page, if at LEVEL 3, or the return to HOME, if at LEVEL 2)

Green buttons provide access to two web sites, and mauve buttons to all of the SECTIONS of this SITE.

First two items to the right provide access to web sites