Figure 7

(a and b). Histopathology of a Sweet's syndrome lesion from a patient with concurrent erythema nodosum. Skin biopsy from one of the Sweet's syndrome plaques on the right dorsal wrist of a woman with concurrent biopsy-confirmed Sweet's sydrome and biopsy-confirmed erythema nodosum. The characteristic histopathologic features of Sweet's syndrome are observed at low (a) and higher (b) magnification: papillary dermal edema, swollen endothelial cells, and a diffuse infiltrate of predominantly neutrophils with leukocytoclasia. There is no evidence of vasculitis (hematoxylin and eosin, × 25 (a), × 100 (b)). (From [21] Cohen PR, Holder WR, Rapini RP: Concurrent Sweet's syndrome and erythema nodosum: a report, world literature review and mechanism of pathogenesis. J Rheumatol 1992;5:814–820. Copyright 1992, Reprinted with permission from the Journal of Rheumatology, Toronto, Ontario.)