Multifocal Germinoma Masquerading as Hypophysis in Young Adult Presenting with Syncope and Panhypopituitarism

A 25-year-old male with Gilbert syndrome developed recurrent syncopal attacks over six months. Cardiac evaluation showed fluctuating blood pressure values. He also complained of loss of libido and weight loss. Hormonal evaluation showed panhypopituitarism with cortisol deficiency. Subsequently, an MRI (magnetic resonance imaging) of the brain was done, which identified pituitary stalk thickening and hypothalamic involvement, raising the possibility of inflammatory hypophysis, lacking the normal posterior pituitary signal. However, in view of non-resolving symptoms after steroid treatment. Further whole-body 18 F-FDG PET/CT was done to rule out any other underlying malignancy, which uncovered hypermetabolic lesions across the infundibulum, hypothalamus, dorsal medulla, and cerebellum. Repeat MRI brain confirmed these lesions. Stereotactic biopsy targeting the medullary lesion was done, which confirmed it to be an intracranial germinoma.