Vasculitides

Medium size and and small arteries show necrotizing vasculitis, thrombi, fibrin deposits, in later stages fibroblastic proliferation and granulation tissue, finally scarring, obliteration and recanalization. Sometimes aneurysmatic dilatation of the vessels may occurr.

Mixed infiltrate (neutrophils, lymphocytes, histiocytes, some plasmocytes, sometimes eosinophils); hemorrhage. Leukocytoclastic vasculitis of small cutaneous vessels is often present as well. Ischemia of supplied tissues may be present as well.

Vasculitis with many eosinophils in the infiltrate, often degranulated.

Perivascular infiltrate with eosinophils, vasculitis with eosinophils, perivascular granulomas, thrombi. May heal with scarring.

Necrosis, perivascular fibrinoid degeneration, leukocytoclasia. Necrotizing vasculitis affecting small and medium dermal blood vessels. Bleeding. Later palisading granulomas with giant cells are formed.

Variable: neutrophils, sometimes eosinophils, thrombi, intimal proliferation in later stages.

Diagnosis is easier if the data of affected organs are available and laboratory examination confirms increased ANCA levels.

Thrombosis of small or medium arteries and (often as well) veins. Mixed perivascular infiltrate (lymphocytes, neutrophiles, eosinophiles, histiocytes and sometimes giant cells). Microabscesses. Later fibrosis and possibly recanalization.

Histology (especially in late stages) is not specific and clinical correlation is important.

Thrombosed venules with fibrin in the dermis, slight lymphocytic inflammatory infiltrate, some neutrophils, bleeding, edema, epidermal necroses and ulcers.

Hyalin microthrombi in various stages of fibrinolysis. Usually some hemorrhage. Inflammatory changes are minimal. In some cases are epidermal necroses or subepidermal bullae.

Arteritis with elastolytic granulomas and presence of giant cells; fibrosis, degeneration and mixed inflammatory infiltration with plasma cells, lymphocytes and histiocytes.

Purpura Majocchi-Schamberg is characterized by slight alteration of superficial capillaries with hemorrhage and perivascular lymphocytic infiltrate.

Purpura Schönlein-Henoch is classified as a vasculitis.

Papillary dermal edema, slight perivascular infiltrate with variable amount of neutrophils, sometimes slight leukocytoclasia, focal slight fibrin deposits of superficial venules, hemorrhage.

Variable perivascular infiltrate with neutrophils, necroses, fibrin deposits. Special staining shows intra- and perivascular mycotis spores and hyphae. Epidermal necroses are often present as well.

Fibrin, nerosis, granulation tissue, sometimes with neutrophils, variable deposits of hemosiderin. The epidermis around is usually acanthotic (pseudoepithelimatous hyperplasia) and sometimes irritated (spongiosis, parakeratosis) as the reaction on extrenal therapy.

Dilated and thrombosed superficial veins.

Dermal veins are filled by thrombi in variable stage of organisation. The wall of the vein as well as surrounding dermal connective tissue is inflammed. In acute cases there are usually many neutrophils.

Homogenous eosinophilic material within dermal venules, dermal hemorrhare and often perivascular and sometimes interstitial infiltration with neutrophils.

Usually characterized by leukocytoclastic vasculitis.

Dilated lymphatic vessels with neutrophils; phlegmone.

Dilated lymphatic vessel containing fibrin thrombus, later replaced by connective tissue (histiocytes, fibroblasts, lymphocytes).