Granulomatosis with Polyangiitis Manifesting as a Symptomatic Sellar Mass in a Young Woman

A pituitary mass is a rare and poorly understood complication of granulomatosis with polyangiitis (GPA). Here we describe the case of a young woman with GPA who presented with signs and symptoms initially suggestive of meningitis but was ultimately found to have hypopituitarism and an enlarging sellar mass. She underwent transsphenoidal biopsy, which revealed an abundance of sterile inflammation and necrosis consistent with GPA-related inflammation. This case demonstrates a rare complication of GPA, i.e., a pituitary mass, initially mimicking meningitis. GPA-related pituitary involvement has an unknown pathogenesis and can have debilitating long-term consequences including chronic hypopituitarism and vision impairment, highlighting the need for further research.