S8C19cP6cEED

S8C19cP6c-2: The vessel to the left of the center of the field shows endothelial swelling and fibrinoid necrosis. The inflammatory infiltrate to the right show a mixed infiltrate with prominent fragments of nuclear debris (leukocytoclasia); the infiltrate in this area, near the vessel, is partitioned by irregular deposits of fibrin.

S8C19cP6c-3: In this field, the lesion shows an increased number of vessels and a fibrosing reaction. The fibrous component shows ill-defined, fibro-histiocytic patterns. This chronic, vasculitic process may progress to a stage in which a fibrosing pattern is the dominant feature.


S8C19cP6c-1: A vessel in the center of the field shows fibrinoid necrosis. As is often the case in a lesion of EED, the endothelial layer is viable. Neutrophils have infiltrated the necrotic wall of the vessel; there is a zone of loose fibrous tissue about the vessel; it contains a mixed infiltrate of neutrophils, lymphocytes, and histiocytes [erythema elevatum diutinum (EED)].

S8C19cP6c-4: The vessel to the right is cut in cross section; its wall is thickened and fibrotic; the fibrous tissue forming the wall of the vessel is delicate. The fibrous tissue to the left of this vessel is composed of loosely spaced, fibrous lamellae that are brightly eosinophilic; the fibrosing reaction in this area takes on some of the qualities of “toxic hyalin;” it contains loose infiltrates of neutrophils and histiocytes.

S8C19cP6c-5: Loosely laminated, eosinophilic, fibrous lamellae form the wall of the vessel cut in cross section, just to the right of the center of the field. The fibrous tissue qualifies as “toxic hyalin;” it probably is a product of repair in an area of fibrinoid degeneration. In all these patterns of “EED,” it is tempting to propose that “EED” is a variant expression of a “pyoderma.”

To next page (along either tier 2 or 3)

Back a page (in spatial sequence along a tier)

Up a tier (if at tier 3, then to parent CHAPTER at tier 2; if at tier 2, then HOME

Mauve buttons to right provide access to SECTIONS of this site

Two green buttons provide access to web sites

Beige buttons (to right) provide access to photomicrographs at tier 3 and to parent CHAPTERS at tier 2; they provide access to pictorials and Chapters that are not represented in the brown cluster above