S6C33P27-EBullosa Acquisita

S6C33P27-1: In this lesion, the basement membrane is preserved along the floor of a subepidermal defect. Dermal papillae are preserved in over-all contours. Vessels of the dermal papillae show endothelial swelling and perivascular edema. The adjacent connective tissue is loosely fibrillated. The changes in the connective tissue could represent edema but, more likely, there is some degree of fibrolysis; some of the changes suggest prominent perivascular edema, but this also could be evidence of stromolysis. Connective tissue cells are activated. There are occasional eosinophils ( EBA).

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S6C33P27-2: The patterns in lesions of EBA are somewhat repetitious and, perhaps, this, in part, is related to sites selected by the clinician for biopsy. The roof of the bulla shows a hyperplastic superficial unit with partial preservation of rete patterns. A portion of the lesion is denuded of epidermis along the surface. Dermal papillae are preserved. The papillary dermis is widened and edematous (pale).

S6C33P27-3: Basal keratinocytes show degenerative changes with increased cytoplasmic acidophilia and pyknosis of nuclei. Focally, the basal layer is interrupted. The roof of the bulla has the characteristics of a hyperplastic superficial unit. The clefting at the dermal-epidermal interface is incomplete in this area (“archiform”). Rete ridges at their extremities are tenuously attached to the dermis. The papillary dermis is widened and fibrotic. On the right between two papillae, pale debris (possibly cellular debris of keratinocyte origin) is condensed in a crevice. On the left, the papilla, at its tip, is pale; this feature probably is evidence of fibrolysis rather than edema. There are loose perivascular infiltrates of lymphoid cells. Connective tissue cells are activated. Focally, perivascular connective tissue is pale (clear); this may represent lysis of connective tissue.

S6C33P27-4: The defects are loculated with attachments loosely preserved at the tips of rete ridges. Basal keratinocytes show cytopathic changes as previously described. Dermal papillae are fibrotic and broad; spaces between the papillae (crevices) are narrow. On the left, a crevice between two papillae contains condensed pale debris, possibly cellular (keratinocytic) debris. The papillary dermis is fibrotic; connective tissue cells are activated. Histiocytes and eosinophils are present in the fibrin in the defect on the right.

S6C33P27-5: Dermal papillae are irregularly spaced. Their contours are distorted; some are thin and elongated. In one elongated papilla to the right, vessels are congested. There is an irregular condensation of a membrane along the surface that qualifies as a partially interrupted basement membrane. The papillary dermis is widened and fibrotic. The tendency for connective tissue cells to form palisades, as seen in cicatricial pemphigoid, is not a prominent feature of the lesions of EBA selected for this presentation. There are mild perivenular infiltrates of lymphoid cells in the upper portion of the reticular dermis.

S6C33P27-6: A lesion of EBA shows a sub-epidermal bulla containing proteinaceous fluid and a loose infiltrate of inflammatory cells. The reaction in the dermis is relatively cell-poor.  The papillary dermis is widened and fibrotic. There are irregular pigment deposits in the roof of the bulla ( EBA).

S6C33P27-7: The roof of the bulla is thin and shows a loss of a defined basal layer. There are irregular pigment deposits. There clusters of necrotic keratinocytes and lytic defects (cytopathic changes). The changes in the roof are of a type commonly seen in sub-epidermal bullous disorders, particularly pemphigoid.

 

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