Mikulicz's Disease with hypophysitis - a new IgG4-mediated disorder.

INTRODUCTION: We present a case of Mikulicz's Disease with hypophysitis. This is a rare clinical association as part of the group of IgG4- related diseases, a group of disorders which can have multiorgan involvement.

METHODS: A 55-year-old male patient was diagnosed with Mikulicz's disease. He was treated with oral steroids for six months with complete resolution. After two years the patient presented with fatigue, generalised weakness, and weight loss of 11 kg over six months. On evaluation he was found to have panhypopituitarism. MRI pituitary revealed homogeneously enlarged, well enhancing pituitary with thickening of the stalk. Serum IgG4 levels were significantly elevated. The patient was treated with methyl prednisolone pulse therapy followed by oral steroids for three months. He developed diabetes insipidus after starting steroid therapy. There was a significant resolution in the enlargement of the pituitary and stalk thickening at three months.

RESULTS: The clinical, biochemical, and radiological findings of hypophysitis associated with Mikulicz's disease are presented with a brief review of literature.

CONCLUSIONS: IgG4-related diseases are rare and have recently been recognised as a cause of hypophysitis. They can have multiorgan involvement. A high index of suspicion is required for clinching this rare diagnosis, which can be confirmed by measurement of serum levels of IgG4. Steroid therapy can reverse the inflammatory changes in IgG4 hypophysitis. (Endokrynol Pol 2016; 67 (6): 622-626).