IgG4-related autoimmune pancreatitis overlapping with Mikulicz's disease and lymphadenitis: a case report.

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis that is categorized as type 1 or type 2 according to the clinical profile. Type 1 AIP, which predominantly presents in a few Asian countries, is a hyper-IgG4-related disease. We report a case of IgG4-related AIP overlapping with Mikulicz's disease and lymphadenitis, which is rare and seldom reported in literature. A 63-year male from Northeast China was admitted for abdominal distension lasting for one year. He presented symmetric swelling of the parotid and submandibular glands with slight dysfunction of salivary secretion for 6 mo. He had a 2-year history of bilateral submandibular lymphadenopathy without pain. He underwent surgical excision of the right submandibular lymph node one year prior to admission. He denied any history of alcohol, tobacco, or illicit drug use. Serological examination revealed high fasting blood sugar level (8.8 mmol/L) and high level of IgG4 (15.2 g/L). Anti-SSA or anti-SSB were negative. Computed tomography of the abdomen showed a diffusely enlarged pancreas with loss of lobulation. Immunohistochemical stain for IgG4 demonstrated diffuse infiltration of IgG4-positive plasma cells in labial salivary gland and lymph node biopsy specimens. The patient received a dose of 30 mg/d of prednisone for three weeks. At this three-week follow-up, the patient reported no discomfort and his swollen salivary glands, neck lymph node and pancreas had returned to normal size. The patient received a maintenance dose of 10 mg/d of prednisone for 6 mo, after which his illness had not recurred.