S8C11bP1b-1: The pattern is classic; it has vasculitic qualities. The epidermis, but for effacement of rete ridges, is relatively unaffected. The papillary dermis is edematous (to the left, in the region that is relatively free of stain). Small vessels in the upper portion of the dermis are surrounded by inflammatory cells (neutrophils, a mixture of lymphocytes, and histiocytes). Inflammatory cells extend from the perivascular spaces into the reticular dermis among collagen bundles. In the zone of the infiltrate, the dermis is edematous; collagen bundles are small and widely spaced. The adjacent dermis shows solar elastosis. In the area of edema in the reticular dermis, there are collections of erythrocytes.

S8C11bP1b-2: The infiltrates are mild, but requisites for the diagnosis of a leukocytoclastic angiitis are satisfied. The small vessel, in cross-section to the left (yellow arrows), is surrounded by a loose meshwork of fibrin (fibrinoid degeneration). Loose infiltrates of neutrophils are present among collagen bundles of the reticular dermis. There are fragments of nuclear debris (leukocytoclastic angiitis).

S8C11bP1b-3: The perivascular infiltrates are mixed. In this area, the vessel is not associated with deposits of fibrin. There are collections of extravasated red blood cells. The pale, wavy, faintly basophilic fibers are elastotic fibers of solar elastosis.