Possible Association Between IgG4-Associated Systemic Disease With or Without Autoimmune Pancreatitis and non-Hodgkin Lymphoma

Objectives: IgG4-associated systemic disease (ISD) is a multiorgan fibroinflammatory disorder whose pancreatic manifestation is called autoimmune pancreatitis (AIP). We describe 3 patients who developed non-Hodgkin lymphoma during the follow-up of ISD. Methods: At our institution's pancreas clinic, we have prospectively and retrospectively examined patients with ISD with (n = 101) or without (n = 10) AIP (mean age, 59 years; 90 males and 21 females). We reviewed the medical records of all 111 patients to identify patients who developed non-Hodgkin lymphoma during the follow-up since their first presentation of ISD. Standardized incidence rate was calculated. Results: The 111 patients with ISD with or without AIP had 331 patient-years of observation during which 3 patients had a diagnosis of non-Hodgkin lymphoma 3 to 5 years after the diagnosis of ISD. In these patients who later developed lymphoma, ISD involved the pancreas (AIP) in 2 and salivary gland in 1. non-Hodgkin lymphoma had extranodal involvement in all patients (liver [n = 2], adrenal glands [n = 1], kidney [n = 1], and lung [n = 1]). Standardized incidence rate was 16.0 (95% confidence interval, 3.3-45.5). Conclusions: We report 3 cases of non-Hodgkin lymphoma that developed during the follow-up of ISD suggesting that patients with ISD may be at an increased risk of developing non-Hodgkin lymphoma.