S8C17P4-4: The perivascular infiltrates are pleomorphic with lymphocytes, histiocytes, eosinophils (red arrows), plasma cells, and even activated mesenchymal cells. Pigment deposits also are represented; hemosiderin deposits are common in lesions of granuloma faciale. The vessel, to the right and just below the center of the field, shows intact endothelium; the endothelial cells have enlarged nuclei with marginated chromatin. There are fibrin deposits in the wall of the vessel (a mesh-work of bright red fibrils).

S8C17P4-5: The grenz zone is well-defined; in this example, the connective tissue of this zone is condensed. The changes in the underlying dermis have a lobular quality in which rigid vessels are regularly spaced in a loosely laminated, fibrous matrix. The patterns have a granulation tissue-like quality. The small vessels have thickened walls; they are outlined by chronic inflammatory cells with a sprinkling of neutrophils. There are fragments of nuclear debris. Vessels have swollen endothelium.

S8C17P4-6: A vessel, just to the right and below the center of the field, shows loosely laminated, “toxic” hyalin with a pleomorphic infiltrate of inflammatory cells among the lamellae. In the region of the blue arrows, the laminated fibers have the quality of fibrinoid.

S8C17P4-7: At a higher magnification, delicate lamellae of hyalin are arranged concentrically around the lumen of a vessel that is cut in cross section. Neutrophils are prominent in the infiltrates to the left of the vessel. Many of the cells show pyknosis and fragmentation (leukocytoclasia) of their nuclei. In the area outlined by blue arrows, coarsely fibrillated deposits of fibrinoid are associated with fragments of nuclei (fibrinoid necrosis and leukocytoclasia). The pattern of fibrinoid necrosis might be characterized as the initial change of a process leading to the formation of “toxic” hyalin (hyalin being the product of a reparative phase).