Non-Neoplastic Dermatopathology

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5 Disorders of the Subcutis

Figure 5.1.1 Erythema nodosum. Marked thickening of the subcutaneous septae by fibrosis and inflammation.

Figure 5.1.2 Erythema nodosum. Septal fibrosis and edema with mixed inflammatory infiltrate. The inflammation and fibrosis encroaches upon the lobules. Note that the vessels are dilated but there is no vasculitis.

Figure 5.1.3 Erythema nodosum. Granuloma formation characterized by loose aggregates of multinucleate giant cells without necrosis. Septae are markedly thickened by fibrosis with reactive vessels.

Figure 5.1.4 Erythema nodosum. Mixed infiltrate including eosinophils, lymphocytes, and plasma cells in addition to multinucleate histiocytes.

Figure 5.1.6 Nodular vasculitis. Predominantly lobular infiltrate with septal edema but no significant septal fibrosis. Copyright © Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited. 2023

Figure 5.1.5 Erythema nodosum. Miescher radial granulomas characterized by macrophages surrounding small cleft-like spaces with clusters of neutrophils.