[An ANCA negative limited form of granulomatosis with polyangiitis (Wegener's granulomatosis) affecting the cavernous sinus].

INTRODUCTION

Granulomatosis with polyangeitis (Wegener's granulomatosis) (GPA) is a granulomatous vasculitis associated with antineutrophil cytoplasmic antibodies (ANCA). Affected organs usually include upper and lower respiratory tracts, and kidneys. Limited forms of GPA may affect the central nervous system (vasculitis, hypertrophic pachymeningitis, encephalitis), a location in which diagnosis is often uneasy.

CASE REPORT: We report a 74-year-old woman who presented with a limited form of GPA affecting the cavernous sinus. Diagnosis was considered in view of a retrospectively suggestive clinical presentation, compatible cerebral MRI and temporal artery biopsy, despite the absence of ANCA. It was supported by a favourable outcome with cyclophosphamide administration.

CONCLUSION

GPA presenting as a cavernous sinus syndrome is rare. Three co-existing pathogenic mechanisms may be involved in GPA affecting the central nervous system: contiguous invasion from nasal or orbitary granulomatous sites, vasculitis, or primary intra-cerebral granulomatous inflammation. Lack of biopsy evidence of affected tissues and ANCA negativity should not delay diagnosis and appropriate therapeutic management in central nervous system GPA.