Unusual Multiorgan Immunoglobulin G4 (IgG4) Inflammation: Autoimmune Pancreatitis, Mikulicz Syndrome, and IgG4 Mastitis
A 58-year-old woman was referred to our institution for nonspecific dyspepsia. She had been medically followed for several years for recurring mastitis of unclear etiology.\nMedical history was significant for thyroiditis diagnosed in 1976. For the last 3 years, she was followed by the Department of Ophthalmology, University Hospital Brno for histologically verified Mikulicz syndrome. Subsequently, salivary function was also tested, but only nonsignificant decrease in function was revealed.\nIn 2006, the patient noticed right-sided submandibular induration; extirpation was carried out for suspected malignancy which was ruled out by histological findings of a fibrotised salivary gland.\nIn 2009, she was examined by the oncology department for recurring mastitis; biopsy findings showed IgG4 infiltrates ( and ). A gastroenterology consult was then recommended for the patient's dyspepsia.\nBased on the patient's prior medical history, AIP was strongly suspected; therefore, serum immunoglobulin levels were tested. Total IgG was elevated (29.77 g/L; normal range, 7 to 16 g/L); IgG4 was more than 3-times the normal limit (920 mg/L; normal range, 8 to 140 mg/L) and rheumatoid factor and antipancreatic duct antibodies also tested positive. According to Japanese criteria, the findings indicated AIP with synchronous IgG4 mastitis and Mikulicz syndrome.\nAbdominal sonography and computed tomography revealed the typical picture of AIP-an enlarged sausage-like pancreas. The steroid treatment led to a normalization of sonographic finding ( and ).\nFurther endosonography confirmed a diffusely enlarged pancreas with rough, unclear outlines, and a small caliber duct.\nThe patient was treated with prednisone at an initial dose of 40 mg for 2 weeks. The dose was then tapered by 5 mg with a maintenance dose of 10 mg of prednisone prescribed for 3 months.\nThe patient has been followed for 1 year after completion of steroid treatment and she is symptoms free with normalized biochemical and sonographic findings. Additionally, the mastitis did not recur during the 12 months period.