Inflammation Masquerading as a tumor, creating physician’s dilemma: A rare presentation of IgG4-related hypophysitis

ABSTRACT IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder. This report presents a case involving a 35-year-old female patient who exhibited symptoms of headaches and secondary amenorrhea. Upon evaluation, she was diagnosed with hyperprolactinemia, in addition to exhibiting low cortisol levels and inappropriately low adrenocorticotropic hormone (ACTH) levels at the time of presentation. Magnetic resonance imaging (MRI) revealed characteristics indicative of a sellar-suprasellar space-occupying lesion, accompanied by apoplexy. Histopathological analysis was carried out, and the lesion was identified as IgG4-related hypophysitis (IgG4-RH). Subsequent imaging with fluorodeoxyglucose positron emission tomography (FDG-PET) identified pancreatic inflammation. The patient was managed with corticosteroid therapy, resulting in a satisfactory clinical response. This case is particularly significant due to the initial diagnostic challenges encountered, as the occurrence of apoplexy in the context of IgG4-RH has not been widely reported in the existing literature.