A Patient with Autoimmune Pancreatitis Type 1 with Previously Known Lymphadenopathy, Both in the Context of IgG4-related Disease.

Background: Autoimmune pancreatitis (AIP) is an important clinical pathologic concept of IgG-4-related disease. AIP is a rare cause of chronic pancreatitis, characterized by a fibroinflammatory process by lymphoplasmacytic infiltrates, storiform fibrosis, obliterative phlebitis, and increased IgG4+ plasma cells, leading to dysfunction of the pancreas. Affected patients with AIP frequently have disease affecting other organs or sites with similar histologic changes, elevated IgG4+ plasma cell infiltrate, and good response to corticosteroid therapy. These diseases often are not limited to the pancreas and the pancreas may not be involved at all.

Methods: We report a 62-year-old man with obstructive jaundice with pre-existent submandibular lymphadenopathy. Diagnosis of AIP was based on diagnostic criteria by the HISORT-criteria in combination with elevated IgG-4 serum levels. CT revealed a focal enlargement of the head of the pancreas, as well as mesenteric peripancreatic and mediastinal lymphadenopathy. He was treated with high-dose steroid in combination with azathioprine and showed good clinical response.

Conclusions: We report a case with pre-existent submandibular lymphadenopathy and obstructive jaundice based on AIP type 1, both in the context of IgG4-related disease.