Isolated intracranial mass lesion near the foramen of Luschka: An unusual presentation of granulomatosis with polyangiitis

Abstract

Granulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmic antibody-associated granulomatous vasculitis. The main central nervous system manifestations of GPA are patchy meningitis, cranial neuropathies, and vasculitis of the cerebral arteries. However, we report the first case of an intracranial mass lesion near the foramen of Luschka. A 68-year-old female with a history of breast cancer and GPA developed dizziness and diplopia. Head magnetic resonance imaging (MRI) revealed an isolated mass lesion near the right foramen of Luschka. The lesion was enhanced on gadolinium-enhanced MRI, and a T2 high-intensity area suspected of edema was found around the lesion. We performed a resection via craniotomy, and the histopathological findings were consistent with GPA. Cyclophosphamide pulse therapy with corticosteroid was markedly effective and reduced the intracranial mass lesion. When a brain tumor is detected in patients with GPA, a granulomatous lesion should be considered as differential diagnosis, and surgical biopsy is essential for definitive diagnosis for early stage treatment.