Findings histopathologic in selected quotations

 
"In the deep part of the cutis and in the subcutaneous fat are vessels with thickened, hyalinized walls that are invaded by polymorphonuclear leucocytes and round cells; most of them are occluded. The heavy infiltrate around the vessels constitutes the only infiltrate in the section." [7]
 
"thickening of wall of arterioles of the cutis and subcutis and occlusion of these vessels, . . ,in two cases the arterioles revealed occlusion by an amorphous pink thrombus. . . . In the biopsies of three patients, . . . thickening of the walls, some fibrosis and obliteration of the lumen of the vein. . . . There was usually a mild to moderate nonspecific infiltrate in the corium which was usually perivascular, with some infiltration of the occluded arterioles and veins. . . . There was relatively little panniculitis or fibrosis of the subcutaneous fat, and no giant cells were evident in any section." [8]
 
"a large vein at the dermal-subcutaneous junction with [au: change OK?] thickened walls, slight perivascular infiltrate and thrombosis of the lumen. In the dermis were several vessels, especially some arterioles, which revealed thrombosis." [9]
 
"small V-shaped areas of necrosis involving the epidermis and superficial corium . . . presence of fibrinoid material in the superficial corium. The fibrinoid was occasionally noted in the stroma in V-shaped areas of necrosis, but generally involved the superficial blood vessels. . . . Some of the superficial blood vessels were usually dilated and engorged with red blood cells and others were occluded and infiltrated by eosinophilic fibrinoid material. . . . A perivascular inflammatory infiltrate that varied from slight to moderate was observed throughout the corium. The predominant cells were lymphocytes and histiocytes, although plasma cells were prominent in two biopsy specimens and eosinophils were prominent in one specimen."
 
"[scarring lesion:] epidermal atrophy and flattening of rete ridges in the central portions of the sections. . . dense collagen bundles and a decreased number of small blood vessels in the corium underlying epidermal atrophy." [11]
 
"The pathological change occurs in the vessels of the middle and lower parts of the dermis at the level of the sweat glands. . . . The small vessels of this lesion (livedo vasculitis) shows thickening, endothelial proliferation, hyaline degeneration of the subintimal layer, and focal thrombosisThe surrounding inflammatory reaction is relatively mild and consists primarily of lymphocytes and few polymorphonuclear cells. Leukocytoclasia is not present, and eosinophils are few or absent. . . . Both arterioles and small veins are involved in this process. . . . Adjacent medium-sized vessels in the panniculus are not involved." [12]
 
"Section from nonulcerated lesion; epidermis is atrophic; a dense parakeratotic scale is present; RBC are scattered through connective tissue of upper dermis; blood vessels of superficial corium are filled with an eosinophilic homogenous material." [14]
 
"In the lower dermis, vessels were small-to-muscular-sized arterioles. . . . Immunoglobulin and complement components were localized to those vessels found to be hyalinized, . . . seven had papillary dermal vessel involvement." [19]
 
"deposition of a homogenous, PAS–positive fibrinoid material within superficial blood vessels without leukocytic infiltration of vascular structures. Vessels beneath the papillary dermis were occasionally involved, but deep dermal and subcutaneous vessels, including muscular vessels were not involved." [22]
 
"All specimens contained extravasated RBCs in the dermis and dilated vessels that were occluded with RBCs in the reticular and deep dermis. . . . Specimens from four of the seven patients showed hyalin thrombi in occluded vessels in the reticular and deep dermis." [15]
 
"fibrinoid degeneration of both capillaries and middle-sized veins in the dermis associated with a small number of perivascular lymphocytic infiltrates. Lumina of vessels were narrowed in many portions and sometimes filled with thrombi." [24]
 
"prominent endothelial cells, fibrinoid thrombi or fibrinoid rings in some vascular lumens and hemorrhage. The vascular changes are distributed in upper, mid-, and deep dermis as well as subcutaneous tissue." [26]
 
"proliferation of superficial dermal blood vessels with a variable number of thromboses present. Interstitium contained extravasated erythrocytes, haemosiderin deposits, and scattered lymphocytes." [16]
 
"diffuse capillary thrombosis in the dermal and subcutaneous vesselsAround the thrombotic areas were no or only moderate perivascular infiltrates." [28]
 
"dilated superficial vessels with perivascular infiltration by mononuclear cells, in addition to thickened vessel walls with thromboses." [30]
 
"A skin biopsy specimen from a purpuric papule showed relatively noninflammatory thrombi within the dermal vessels, with intramural and intraluminal deposition of fibrin." [32]
 
"In all cases, skin biopsy showed epidermal infarction and thrombotic occlusion in the mid-dermal vessels without vasculitis." [33]
 
"biopsy showed evidence of a hyalinizing vasculitis with fibrinoid deposits around the vessels and thrombosis within." [34]
 
"Allspecimens showed endothelial thickening, focal hyalinization, extravasated erythrocytes and a small perivascular lymphocytic infiltrate associated with a variable number of thrombi in the middermal and upper dermal vessels. . . . No sign of fibrinoid necrosis of the dermal vessels was seen." [17]
 
"A biopsy specimen from a purpuric plaque showed hyaline degeneration, fibrin plugs, and thrombosis on the small vessels of the dermis." [35]
 
"Results of skin biopsy revealed inflammatory post capillary venules, hemorrhage, and fibrin clots." [38]
 
"microvascular thrombi and fibrinoid changes of the vessel wall. Inflammatory vasculitis was not seen." [39]
 
"hyalinization of papillary and superficial reticular dermis and minimal perivascular lymphocytic infiltrate." [40]