Chronic Ileum Obstruction, Granulation, and Ulceration With IgG4-Positive Plasma Cell Infiltration in a Six-Year-Old Girl With 21trisomy.

Patients with 21trisomy often develop congenital or acquired gastrointestinal diseases, such as duodenal or anal atresia, celiac disease, intussusception, and constipation. In these patients, it is often challenging to diagnose gastrointestinal diseases because most patients have difficulty explaining their complaints in detail. Furthermore, these patients also possess immunological disorders, such as increased type I interferon activation, innate immune hypersensitivity, and polarization to autoimmune. Here, we present a girl with 21trisomy and constipation who developed severe anemia, occult blood and elevated levels of calprotectin in stool, and chronic ileum obstruction confirmed by computed tomography. The patient underwent surgical resection of the ileum and recovered without complications. Pathological examination demonstrated intussusception, ischemia, ulceration, inflammatory granulation, and massive IgG4-positive plasma cell infiltration. After the surgery, her fecal calprotectin levels were normalized. We assumed that the ileum inflammation caused by ileum dilation generated ulcers and granulation, which could be associated with immunological, gastrointestinal, and intellectual disorders in patients with 21trisomy.