Pituitary Abscess as Manifestation of IgG4-Related Hypophysitis: A Case Report

Abstract

IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition with heterogeneous organ-specific manifestations. IgG4-related hypophysitis results from pituitary involvement and represents a rare neuro-ophthalmic complication of IgG4-RD, but the presentation as pituitary abscess is exceptional. We report the case of a 38-year-old otherwise healthy woman with a 3-year history of relapsing pituitary sterile abscess repeatedly treated with neurosurgery and antimicrobials. Histological re-examination of pituitary biopsy specimens revealed a dense inflammatory infiltrate rich in IgG4-positive plasma cells. Serum IgG4 levels were normal and circulating plasmablasts were increased. A diagnosis of IgG4-related hypophysitis was made and the patient treated with high-dose steroid pulse therapy with subsequent reduction of the pituitary lesion and resolution of symptoms. This case highlights how the diagnostic intuition on the basis of histopathology has changed management with prompt dramatic response to steroid therapy.