Skin nontumor

Dermal perivascular and vasculopathic reaction patterns

Segmented hyalinizing vasculitis



Topic Completed: 1 August 2011

Minor changes: 10 November 2020

Copyright: 2002-2021, PathologyOutlines.com, Inc.

PubMed Search: Vasculitis [title] skin

Mowafak Hamodat, M.B.Ch.B., M.Sc.
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Cite this page: Hamodat M. Segmented hyalinizing vasculitis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorsegmentedhyalinizingvasculitis.html. Accessed October 25th, 2021.
Definition / general
  • Manifestation of a thrombogenic vasculopathy in which occlusion of small dermal vessels by fibrin thrombi is the primary event
Terminology
  • Also called atrophie blanche of Milian
Clinical features
  • Affects lower legs, particularly ankles and dorsum of feet, rarely the extensor arm surfaces below the elbows
  • Elevated levels of fibrinopeptide A are suggestive of a thrombogenic state
  • Several cases with lupus-type anticoagulant and increased level of anticardiolipin antibodies have been reported
  • Other associations include protein C deficiency, factor V Leiden mutation, prothrombin mutation, plasminogen activator inhibitor-1 promoter mutation (OMIM 173360), antithrombin III deficiency, methylenetetrahydrofolate reductase mutation (OMIM 607093), homocysteinemia and essential cryoglobulinemia, all of which contribute to a hypercoagulable condition

  • Description: painful purpuric ulcers with reticular patterning on the lower extremities
Treatment
  • Antiplatelet drugs and antithrombotic drugs may be useful
  • Also dapsone, nicotinic acid, intravenous immunoglobulin, PUVA therapy, danazol and hyperbaric oxygen therapy
  • Warfarin therapy is sometimes used to treat the associated / concurrent abnormalities in one or more clotting factors
  • Also cessation of smoking, low dose aspirin, oral pentoxifylline and oral dipyrimadole
  • Folic acid is recommended for those with an MTHFR mutation, hydrochloroquine for patients with antiphospholipid antibodies and anabolic steroids (stanozolol or danazol) for patients with cryofibrinogenemia
Microscopic (histologic) description
  • Dermal capillaries have focal endothelial proliferation and wall thickening by PAS+ material, with fibrin thrombi causing occlusion
  • Specific changes vary by age of lesion
  • Primary event is formation of hyaline thrombi in lumen of small vessels in upper and mid dermis; rarely deeper vessels are involved; PAS+ diastase resistant fibrinoid material also present in walls of blood vessels and in perivascular stroma; also infarction of superficial dermis, often with a small area of ulceration
  • Sometimes a thin parakeratotic layer is present overlying infarcted or atrophic epidermis
  • Epidermis adjacent to ulceration may be spongiotic; a sparse perivascular lymphocytic infiltrate may be present, but there is no vasculitis
  • Neutrophils, if present, are usually sparse and confined to infarcted upper dermis and ulcer base
  • Often extravasated red cells in upper dermis
  • Small blood vessels often increased in adjacent papillary dermis, but this is a common feature in biopsies from lower legs
  • In older lesions, there is thickening and hyalinization of dermal vessels with some endothelial edema and proliferation
  • Fibrinoid material may also be present in vessel walls
  • In even older lesions, there is dermal sclerosis and scarring with some dilated lymphatics and epidermal atrophy; there may be a small amount of hemosiderin in upper dermis
  • As old lesions may become involved again, it is possible to find dermal sclerosis in some early lesions
Positive stains
  • Immunofluorescence will demonstrate fibrin in vessel walls in early lesions; in later stages there are also immunoglobulins and complement components in broad bands about vessel walls
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