We report a case of a 50-year-old male admitted to the Endocrinology Unit because of persistent headaches, nausea, feeling tired, sudden weight loss, cold intolerance, decreased appetite, and lack of sex interest. Diagnostic workup showed a 6-millimeter pituitary tumor without signs of compression, and a condition of progressive panhypopituitarism. After 12 months of hormone replacement therapy, the patient was hospitalized because of sudden weight gain, periorbital-peripheral edema, severe dyslipidemia, hypertension, and proteinuria. Corticosteroid therapy was shifted from oral to continuous intravenous infusion, and once the diagnosis of “immune complex-mediated glomerulonephritis with mesangial deposits suggestive for membranoproliferative glomerulonephritis type IIIIgG4-positive” was made, the immunosuppressant mycophenolate (1500 mg/day) was started. After a 6-month follow-up, the complete resolution of renal symptoms was accompanied by the disappearance of a pituitary lesion and the patient was back to prior hormone replacement therapy. Autoimmune hypophysitis (AH) is a rare autoimmune inflammatory disease of the pituitary gland that can impair hormone secretion and function. IgG4-hypophysitis is rare and is usually associated with other IgG4-related diseases. Herein, we describe a rare case of AH associated with late renal disease, and without any other organ involvement.
