title: Orbital inflammatory pseudotumor due to hypersensitivity vasculitis and mononeuritis multiplex in a patient with atypical, cANCA-positive Wegener's granulomatosis.
abstract: OBJECTIVE
  We report on a 60-year-old woman with a retro-orbital pseudotumor and polyneuropathy. The retro-orbital inflammation was histologically diagnosed as hypersensitivity vasculitis (HV). As cytoplasmatic antineutrophilic cytoplasmatic antibody (cANCA) and anti-proteinase-3 antibody were detected, the differential diagnosis also included atypical Wegener's granulomatosis. Hypersensitivity vasculitis is defined as small-vessel vasculitis mediated by the deposition of immune complexes (Arthus reaction) after exposure to various agents such as drugs, toxins, and infections. Since an inflammatory retro-orbital pseudotumor due to HV has not previously been reported, the following case is presented.
  
  
  METHODS
  Magnetic resonance imaging (MRI) revealed retro-orbital infiltrate without granuloma. Histology from an orbital biopsy confirmed HV. Electromyography was used for the diagnosis of polyneuropathy. Serum investigation indicated erythrocyte sedimentation rate (ESR) >100 mm/h, C-reactive protein (CRP) 223 mg/l, antinuclear antibodies 1:80, and cANCA 100 U/ml.
  
  
  RESULTS
  The bilateral orbital pseudotumor, polyneuropathy, and serum levels of inflammation reactants (ESR and CRP) improved from therapy with corticosteroids (1 g of methylprednisolone initially) and azathioprine (150 mg/day).
  
  
  CONCLUSIONS
  Because of cANCA and anti-proteinase-3 antibody positivity, this case can be viewed more as an atypical Wegener's granulomatosis than a systemic HV. The causal variety of inflammatory orbital pseudotumor, including HV and different therapeutic consequences, requires histological differentiation from usual orbital pseudotumors.
authors.affiliation: Division of Rheumatology and Osteology, Department of Internal Medicine IV, Friedrich Schiller University, Erlanger Allee 101, 07740, Jena, Germany. joerg.kaufmann@med.uni-jena.de
authors.forename: Jörg
authors.initials: J
authors.lastname: Kaufmann
authors.forename: Eberhard
authors.initials: E
authors.lastname: Schulze
authors.forename: Ulrich
authors.initials: U
authors.lastname: Voigt
authors.forename: Jürgen
authors.initials: J
authors.lastname: Strobel
authors.forename: Gert
authors.initials: G
authors.lastname: Hein
authors.forename: Günter
authors.initials: G
authors.lastname: Stein
mesh_terms: D019268:Antibodies, Antineutrophil Cytoplasmic / Q000032:analysis*; D001379:Azathioprine / Q000627:therapeutic use; D015415:Biomarkers / Q000032:analysis; D004359:Drug Therapy, Combination; D004576:Electromyography; D005260:Female; D014890:Granulomatosis with Polyangiitis / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008775:Methylprednisolone / Q000627:therapeutic use; D008875:Middle Aged; D020422:Mononeuropathies / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D009915:Orbit / Q000473:pathology; D016727:Orbital Pseudotumor / Q000188:drug therapy / Q000209:etiology / Q000473:pathology*; D016896:Treatment Outcome; D018366:Vasculitis, Leukocytoclastic, Cutaneous / Q000150:complications / Q000188:drug therapy / Q000473:pathology*
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D015415:Biomarkers; D007166:Immunosuppressive Agents; D001379:Azathioprine; D008775:Methylprednisolone