Systemic IgG4-related disease with extensive peripheral nerve involvement that progressed from localized IgG4-related lymphadenopathy: an autopsy case

A 77-year-old man, with a lengthy medical history of chronic dysuria, constipation, hypertension, myocardial infarction, and a submandibular lymphadenopathy that was excised 3 years ago, was hospitalized due to elevated liver enzyme levels. He demonstrated hypergammaglobulinemia, hyperproteinemia, high levels of IgG and IgG4, eosinophilia, sclerosing cholangitis, and retroperitoneal fibrosis. He was diagnosed with IgG4-related disease (IgG4-RD). While hospitalized, he had several episodes of syncope while standing and was diagnosed with autonomic nerve dysfunction. Thirty days after hospitalization, he died of nonocclusive mesenteric ischemia (NOMI). Post-mortem, his submandibular lymphadenopathy lesion was diagnosed with progressively transformed germinal center (PTGC)-type IgG4-related lymphadenopathy. At autopsy, small and large intestines showed mucosal necrosis and the wall muscles of the transverse to sigmoid colon were necrotic. The sigmoid colon was fibrotic and infiltrated with numerous IgG4⁺ plasma cells and eosinophils; infiltration into Auerbach’s plexus was also observed. The IgG4-RD lesions were also detected in the mesentery of the sigmoid colon, retroperitoneal soft tissue, abdominal aorta, liver, extrahepatic bile duct, bilateral lungs, bilateral kidneys, urinary bladder, prostate, epicardium, bilateral coronary arteries, and lymph nodes. Interestingly, infiltration into the lesions was most notable around the peripheral nerves in every organ. Thus, this case describes an IgG4-RD that progressed from PTGC-type IgG4-related lymphadenopathy to systemic IgG4-RD, suggesting that IgG4-RD may affect many organs through peripheral nerve involvement.