ABSTRACT
IgG4-related disease (IgG4-RD) is a rare form of autoimmune sclerosing disease, characterised by elevated serum IgG4 and tissue IgG4 levels, specific histopathological findings, multiorgan involvement and adequate response to glucocorticoid treatment. The low incidence and the heterogeneous nature of the disease has made consensus on diagnostic criteria for IgG4-RD difficult. Whether sclerosing mesenteritis (SM) is considered a manifestation of IgG4-RD is strongly debated. We present the case of a patient with a history of rheumatoid arthritis who presented with a calcified abdominal mass. She was found to have an isolated, pedunculated mesenteric mass positive for IgG4 and concurrently elevated serum IgG4 levels. Clinical features did not classify her disease as either SM or IgG4-RD as currently described in consensus statements. Concurrent diagnoses of IgG4-RD, SM and other autoimmune disorders, as well as postoperative recommendations for resected isolated IgG4-positive masses, are discussed.
