Immunoglobulin G4‐related disease accompanying a small intestinal ulcer: A case

IgG4-related disease complicated with diffuse and chronic gastrointestinal inflammation leading to small intestinal perforation

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a systemic inflammatory disease characterised by elevated serum IgG4, IgG4+ cell infiltration, storiform fibrosis, and obliterative phlebitis. While IgG4-RD can affect various organs, gastrointestinal tract involvement is less common. Here, we report a 70-year-old female with IgG4-RD complicated with diffuse and chronic gastrointestinal inflammation, which led to small intestinal perforation. She had been suffering from anorexia, abdominal pain, vomiting, and diarrhoea and hospitalised due to recurrent ileus. Consequently, she was referred due to small intestinal perforation required for surgical intervention. Pathology revealed acute and chronic inflammation with massive IgG4+ plasmacyte infiltration into mucosa of the small intestine and ischaemic change secondarily caused by chronic inflammation. Random biopsies from the mucosa of stomach, duodenum, ileum, and colon also revealed diffuse and massive IgG4+ plasmacyte infiltration in stomach, duodenum, small intestine, and colon. She was diagnosed with IgG4-RD based on the pathological findings and elevated serum IgG4 levels. Glucocorticoid rapidly ameliorated the symptoms. IgG4-RD may cause gastrointestinal manifestations, and histopathological assessment should be considered, even in the absence of specific characteristics of IgG4-RD.

[A case of suspected IgG4-related hypophysitis presented with panhypopituitarism and central diabetes insipidus]

A 78-year-old man complained of subacute general fatigue and anorexia, following diplopia and gait disturbance. He demonstrated wide-based and small-stepped gait without objectively abnormal ocular movements. Brain ‍MRI showed enlargement of the pituitary stalk and gland with uniform contrast enhancement. PET-CT showed FDG ‍uptake in the pituitary gland, mediastinal lymph nodes, and left hilar lymph nodes. Blood investigations revealed panhypopituitarism and high serum IgG4 levels up to 265 ‍mg/dl. Histopathological examination revealed no IgG4-positive cell infiltration in the biopsied mediastinal lymph nodes. However, we suspected IgG4-associated hypophysitis based on the clinical symptoms and MRI findings, which were markedly resolved with steroid. Central masked diabetes insipidus was manifested, but was improved with oral desmopressin. We should pay close attention to the fact that IgG4-related hypophysitis may present with various symptoms regarded as indefinite complaints related to aging or underlying diseases, especially in elderly patients with multimorbidity.

Immunoglobulin G4-Related Disease of the Intestine: A Clinicopathological Entity to Be Considered

Background and Objectives: Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized immune-mediated, systemic condition of unknown etiology, associated with fibroinflammatory lesions. Diagnosis is set in the presence of IgG4-positive plasma cell infiltration of the involved tissue and elevated serum IgG4 levels. However, approximately 30% of patients have normal serum IgG4 levels. IgG4-RD may affect several organs, including the pancreas, bile ducts, mesentery, retroperitoneum, and salivary glands, but the involvement of the gastrointestinal tract is uncommon. Materials and Methods: The case series of 4 patients with IgG4-RD involving the intestinal tract was observed in the period of 2017-2022. Colorectal and ileal biopsy specimens were stained with hematoxylin and eosin and immunohistochemical techniques using monoclonal antihuman IgG4 primary antibody. Diagnosis of IgG4-RD was based on the presence of >50 cells/ HPF and IgG4/IgG ratio >40 confirmed by two pathologists. Results: IgG4-RD was set in patients previously diagnosed as affected by Crohn's disease. Conclusions: Systematic IgG4 immunohistochemical staining should be considered in the diagnostic workup of patients with gastrointestinal strictures, mimicking Crohn's disease. The exact prevalence of the condition is likely more frequent than reported and should be defined by a large series of consecutive patients.