[Intestinal non-Hodgkin lymphoma: "immunoproliferative small intestinal disease"]

Immunoproliferative Small Intestinal Disease Diagnosed by Double-balloon Endoscopy with Biopsy Sampling

We herein report an 80-year-old man diagnosed with immunoproliferative small intestine disease (IPSID) via small bowel endoscopy with a biopsy. He developed persistent diarrhea and subsequently presented with hypoproteinemia and moderate anemia. Transanal double-balloon endoscopy showed prominent villous edema in the middle and lower ileum, while a histological examination showed high lymphocyte/plasma cell infiltration in the mucosal layer. Furthermore, an immunostaining analysis showed that Cluster of differentiation (CD) 3 and CD20 were partially positive, while CD138 was diffusely positive. Immunoglobulin A positivity was also observed. He was diagnosed with IPSID and received a nutritional agent and minocycline. After three months, the patients' symptoms improved.

Extranodal Marginal Zone Lymphoma Presenting within the Meckel Diverticulum as Diverticulitis: A Case Report

Meckel diverticulum is the most common congenital defect of the gastrointestinal tract. It can be asymptomatic or mimic appendicitis and may be complicated by bleeding, diverticulitis, obstruction, and, rarely, neoplasia. We report the first case of extranodal marginal zone lymphoma occupying a Meckel diverticulum. A 44-year-old man with history of colonic diverticulitis presented to the emergency department for evaluation of acute abdominal pain. Radiography showed enteric obstruction, prompting diagnostic laparoscopy. Above the level of mid-ileum an intact Meckel diverticulum was identified. Microscopy showed extensive infiltration of sheets of small lymphocytes with abundant cytoplasm (monocytoid B-cells) prominently in submucosa and focally transmural involving serosal adipose tissue with multiple reactive germinal centers. The immunostains showed positivity for CD20, BCL-2, and CD43 (weak) and negativity for CD3, CD5, BCL-1, CD10, and BCL-6 in monocytoid B-cells. Fluorescence in situ hybridization studies revealed API2-MALT1 fusion signals consistent with t(11;18)(q21;q21), which confirmed the diagnosis of extranodal marginal zone lymphoma, also known as mucosa associated lymphoid tissue lymphoma.