Mucosa-associated lymphoid tissue (MALT) lymphoma is a group of extranodal lymphomas that originate from B cells. Primary colonic MALT lymphoma is a rare disease, and there is no consensus on its endoscopic features and standard therapies. It is essential to raise awareness of colonic MALT lymphoma and choose the appropriate treatment.

In this case report, we describe a 0-IIb-type lesion that was found by electronic staining endoscopy and magnifying endoscopy. The patient underwent a definitive diagnostic ESD for diagnosis. The patient was evaluated for lymphoma after diagnostic ESD according to the Lugano 2014 evaluation criteria, which are divided into imaging remission on the basis of CT and/or magnetic resonance imaging (MRI) evaluation and metabolic remission on the basis of PET-CT evaluation. Based on the PET-CT results suggesting increased glucose metabolism in the sigmoid colon, the patient underwent additional surgical treatment. According to the pathological results of the surgery, we found that ESD could treat such lesions, which may provide a new option for colorectal MALT lymphoma.

The low incidence of colorectal MALT lymphoma, especially for 0-IIb lesions, which are difficult to detect, requires the use of electronic staining endoscopy to improve the detection rate. The combination with magnification endoscopy can improve the understanding of colorectal MALT lymphoma, which ultimately requires pathological support for diagnosis. According to our experience with the present patient case, ESD seems to be a feasible and economical choice for the treatment of massive colorectal MALT lymphoma. However, the combined application of ESD and another therapy scheme needs further clinical investigation.

Mucosa-associated lymphoid tissue (MALT) lymphoma is a subtype of non-Hodgkin lymphoma that is mainly involved in the gastrointestinal tract. The synchronous occurrence of colonic MALT lymphoma and adenocarcinoma in the same patient is extremely rare. We here report a case of synchronous colonic MALT lymphoma found on surveillance colonoscopy five months after surgery and chemotherapy for sigmoid adenocarcinoma.

A 67-year-old man was admitted because of hematochezia for two months. Colonoscopy suggested a colonic tumor before hospitalization. Abdominal computed tomography (CT) revealed local thickening of the sigmoid colon. The patient underwent a left hemicolectomy with local lymph node dissection. The histopathology revealed moderately differentiated adenocarcinoma and partially mucinous adenocarcinoma. The pTNM stage was T3N1Mx. The patient received chemotherapy with six cycles of mFOLFOX6 after surgery. Colonoscopy was performed five months later and revealed single, flat, polypoid lesions of the colon 33 cm away from the anus. Subsequently, the patient underwent endoscopic mucosal resection for further diagnosis. The pathological diagnosis was MALT lymphoma. Positron emission tomography /CT suggested metastasis. The patient refused further treatment and died ten months later.

Colonic MALT lymphoma may occur after surgery and chemotherapy for adenocarcinoma as a synchronous malignancy. Regular surveillance colonoscopy and careful monitoring after surgery are critical.

 = 1). Remission was achieved in 8 cases. Three patients relapsed, and 2 were re-treated. At the end of the study period, 67% of the patients were in remission. All patients were symptom-free. This current series of colonic MALT lymphomas shows the indolent nature of the disease, which may be treated with various modalities.

Colonic mucosa-associated lymphoid tissue (MALT) lymphoma is very rare, especially those which form a mass. Although the characteristics and treatment methods of gastric MALT lymphomas are well established, those of colonic MALT lymphomas have been insufficiently described. Here, we report a case of mass-forming cecal MALT lymphoma that was successfully treated by laparoscopy-assisted bowel resection. A 60-year-old woman with right lower abdominal pain and a palpable tumor was referred to our hospital. Colonoscopy showed a smooth elevated submucosal tumor-like lesion in the cecum. Histological and immunochemical findings were consistent with MALT lymphoma. Serum tumor marker levels were within normal range. Enhanced abdominal computed tomography showed a large tumor 55 mm in diameter in the cecum and edema of a few paracolic lymph nodes. The tumor was diagnosed as cecal MALT lymphoma classified as stage II1 by Lugano classification, and laparoscopy-assisted ileocecal resection was performed. The postoperative course was uneventful and the patient underwent eradication therapy for Helicobacter pylori. A year after the operation she has had no recurrence. In patients with mass-forming colonic MALT lymphoma without dissemination, surgical resection may be a feasible treatment.

A 63-year-old man with abdominal discomfort was referred to our hospital. Colonoscopy revealed a hemispherical-shaped protruding cecal mass of approximately 10 mm in size with a normal mucosal surface. Biopsy specimens showed nodules consisting of the proliferation of atypical lymphoid cells. Mucosa-associated lymphoid tissue (MALT) lymphoma was diagnosed based on the histological and immunohistochemical findings. Since upper gastrointestinal endoscopy demonstrated Helicobacter pylori-associated atrophic gastritis, eradication therapy was administered. The cecal mass disappeared completely within three months after triple therapy. Therefore, H. pylori eradication therapy may be a useful treatment option for cecal MALT lymphoma.