Cutaneous Vasculitis Update:
Figure 11. Endarteritis obliterans—a chronic rather than acute consequence of vasculitis leading to tissue ischemia and infarction due to loss of the vessel lumen. This biopsy was taken from a patient with giant cell arteritis who developed scalp necrosis: occluded muscular vessels were identified in the deep dermis underlying his ulcer.
Figure 12. In the early phase of endarteritis obliterans as found in Sneddon syndrome is a sponge-like plug of mononuclear cells, containing fibrin and erythrocytes in its interstices; this stage follows the initial insult produced by lymphocytic endothelialitis as illustrated in Figure 10. Also note the expansion of the intimal region (arrow) by fibromyxoid tissue admixed with nuclear debris that diminishes the vascular lumen.
Figure 13. Incidental vasculitis. Punch biopsy of an excoriation reveals marked fibrin deposits affecting superficial vessels underlying the ulcerated surface, but no changes affecting mid and deep dermal vessels.
Fig 14 Incidental vasculitis occurring in pustular dermatosis of
the dorsum of the hands (aka, pustular vasculitis). Note that the
focus of fibrinoid necrosis (circle) in a sea of neutrophils and
nuclear debris. Vasculitis in this histologic setting is suspected
to represent an effect to reactive neutrophilic byproducts
Fig 15.The finding of extravascular collagenolytic granulomas can be a clue to the presence of systemic vasculitis such as Wegener granulomatosis, rheumatoid vasculitis, and Churg-Strauss syndrome. These findings can be seen in the absence or presence of necrotizing vasculitis. The ‘‘blue’’ extravascular granuloma illustrated herein is due to basophilic degeneration of collagen bundles that are coated with nuclear debris and can occur in the setting of Wegener granulomatosis (this biopsy) or rheumatoid vasculitis.
Fig 16 Interface dermatitis and vasculitis. Perniosis and connective tissue diseases such as lupus erythematosus and dermatomyositis can simultaneously exhibit interface dermatitis and lymphocytic vasculitis. In this example of perniosis, both fibrin occluding a small vessel (circle) obscured by a lymphocytic infiltrate and necrotic keratinocytes (arrow) near the dermal-epidermal junction are present.
Fig 17. Patterned fibrosis. Lamellar, storiform, and concentric vascular fibrosis can be found in chronic lesions of neutrophilic small vessel vasculitis. In this case of inflammatory pseudotumor, concentric and lamellar fibrosis is evident and associated with a mixed inflammatory infiltrate. Focally, fibrin deposits can be identified in small vessels associated with nuclear debris (arrow).
Fig 18 Complement deposition, C3, is one of the most frequent immunoreactants identified in small vessel cutaneous vasculitis, and it persists the longest, found in lesions more than 72 hours old.
Fig 19 Eosinophilic vasculitis, as identified in Churg- Strauss syndrome or associated with connective tissue disease exhibits marked angiocentric infiltrates of eosinophils associated with eosinophilic degranulation. Fibrin deposits are typically not abundant; none are identified in this case, but the endothelial cells are swollen, occluding the lumen allowing a diagnosis of vasculitis.
Fig 20 Direct immunofluorescence
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