A case of Mikulicz's disease complicated by autoimmune pancreatitis, in which impaired glucose tolerance was improved by glucocorticoid treatment

Abstract

A 73-year-old woman had experienced dry mouth and swellings of both upper eyelids from 1998. In October 2003, she also developed bilateral submandibular swellings, and was diagnosed with diabetes mellitus and prescribed antidiabetic medication. She consulted our hospital in the summer of 2004 due to the exacerbation of eyelid swelling, and was admitted in October 2004. Keratoconjunctivitis sicca was not present. CT and MRI of the head showed bilateral enlargement of the lacrimal and submandibular glands. Serological investigations revealed hypergammaglobulinemia, but as antinuclear antibody and anti-SS-A antibody were absent, further investigation was performed. Serum concentrations of IgG4 were elevated and biopsy of the minor salivary gland revealed a severe infiltration of IgG4-positive plasmacytes. The patient was therefore diagnosed with Mikulicz's disease. Abdominal CT demonstrated diffuse pancreatic swelling, and endoscopic retrograde cholangio-pancreatography revealed stricture of the common bile duct and main pancreatic duct, suggesting the complication of autoimmune pancreatitis. Treatment was commenced with 40 mg/day of prednisolone. This resulted in rapid resolution of the lacrimal and submandibular gland swellings and recovery of salivary gland function. Diffuse swelling of the pancreas and stricture of the common bile duct and main pancreatic duct also improved, and endogenous insulin secretion increased. Both Mikulicz's disease and autoimmune pancreatitis presented with elevated serum IgG4 and infiltration of IgG4-expressing plasma cells into the glandular tissues. We recently proposed the new diagnostic entity of "IgG4-related plasmacytic exocrinopathy"; however, if diabetes mellitus in autoimmune pancreatitis was caused by direct dysfunction of pancreatic cells, we must reconsider this pathogenesis and consider a wider concept including exocrine as well as endocrine glands. This case, in which both types of glands were affected, is therefore of considerable interest.