Colonic mucosa-associated lymphoid tissue lymphoma

Endoscopic and Histopathological Characteristics of Gastrointestinal Lymphoma: A Multicentric Study

Background: Extranodal non-Hodgkin lymphoma (NHL) is more prevalent in the gastrointestinal (GI) tract than in other sites. This study aimed to determine the endoscopic characteristics of primary gastrointestinal non-Hodgkin lymphomas. Methods: We investigated 140 patients from three tertiary referral hospitals with primary malignant lymphoma of the gastrointestinal tract. Characteristics of the lesions were evaluated and analyzed using image-enhanced endoscopy, endoscopic ultrasound, and histopathology. Results: The median age was 60.5 (range: 11-99), and 59 (42.1%) were female. The most frequent complaint was abdominal pain (74.3%), followed by bloody feces (10%) and diarrhea (2.9%). B symptoms were observed in 15 (10.7%) patients. GI obstruction was the most common complication (10.0%), followed by hemorrhage (7.9%) and perforation (1.5%). Regarding endoscopic findings, the identified sites were the following: the stomach (61.4%), colon (10%), small intestine (10%), ileocecum (8.6%), rectum (6.4%), and duodenum (3.6%). Diffuse large B-cell lymphoma (DLBCL) and mucosa-associated lymphoid tissue (MALT) lymphoma are most prevalent in the stomach. Helicobacter pylori was identified in 46 cases (39.0%), with MALT lymphoma being the most infected subtype. Nearly all gastrointestinal non-Hodgkin lymphomas manifested as superficial type (25-59.6%) and ulcer type (15.6-50%) under endoscopy. We found that fungating type and protruding with ulcer type were more frequent types of aggressive lymphomas (diffuse large B-cell lymphoma, mantle cell lymphoma, and T-cell lymphoma) compared to the indolent types (MALT lymphoma, follicular lymphoma, duodenal-type follicular lymphoma, and small lymphocytic lymphoma) (p < 0.05). Conclusions: This study showed that most subtypes of gastrointestinal non-Hodgkin lymphomas exhibited same endoscopic features (superficial type and ulcer type). Aggressive gastrointestinal non-Hodgkin lymphomas (diffuse large B-cell lymphoma, mantle cell lymphoma, and T-cell lymphoma) were highly suspected when fungating lesions and protruding with ulcer lesions were encountered under endoscopy. Endoscopists should be aware of the connection between enhanced endoscopic characteristics and histological varieties of gastrointestinal lymphoma to improve diagnosis.

Colonic mucosa-associated lymphoid tissue lymphoma: A case report

Background

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.

Case presentation

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.

Conclusion

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 in the Gastrointestinal Tract in the Modern Era

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) typically arises from sites such as the stomach, where there is no organized lymphoid tissue. Close associations between Helicobacter pylori and gastric MALT lymphoma or Campylobacter jejuni and immunoproliferative small intestinal disease (IPSID) have been established. A subset of tumors is associated with chromosomal rearrangement and/or genetic alterations. This disease often presents as localized disease, requiring diverse treatment approaches, from antibiotic therapy to radiotherapy and immunochemotherapy. Eradication therapy for H. pylori effectively cures gastric MALT lymphoma in most patients. However, treatment strategies for H. pylori-negative gastric MALT lymphoma are still challenging. In addition, the effectiveness of antibiotic therapy has been controversial in intestinal MALT lymphoma, except for IPSID. Endoscopic treatment has been noted to usually achieve complete remission in endoscopically resectable colorectal MALT lymphoma with localized disease. MALT lymphoma has been excluded from post-transplant lymphoproliferative disorders with the exception of Epstein–Barr virus (EBV)-positive marginal zone lymphoma (MZL). We also describe the expanding spectrum of EBV-negative MZL and a close association of the disease with the gastrointestinal tract.

Clinicopathologic Findings in Patients With Initial Diagnosis of Extranodal Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue (MALT) in Colorectal Mucosa

OBJECTIVES

To evaluate clinicopathologic features, management, and behavior of colorectal extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT).

METHODS

Clinical data, laboratory studies, and radiographic records were reviewed (2005-2018), and fluorescence in situ hybridization studies were performed.

RESULTS

Eleven patients were identified, six of whom were discovered as an incidental finding on endoscopy. Morphologic and immunophenotypic features were similar to MALT lymphomas at other sites except that lymphoepithelial lesions were uncommon. Three of nine patients were positive for BIRC3/MALT1 fusions, two of whom had identical B-cell clones identified in subsequent gastric biopsy specimens. Eight of 10 patients had no clinically evaluable disease after observation (±antibiotics; n = 4) or radiation/chemotherapy (n = 4).

CONCLUSIONS

Patients with incidental and localized colonic MALT lymphoma demonstrated an excellent prognosis with conservative management, although longer follow-up and data based on consistent staging and surveillance methods (including gastric evaluation) are necessary for informed management.

Successful Endoscopic Resection of Primary Rectal Mucosa-Associated Lymphoid Tissue Lymphoma by Endoscopic Submucosal Dissection: A Case Report

Mucosa-associated lymphoid tissue (MALT) lymphoma arises in extra-nodal sites from the malignant transformation of B lymphocytes that are mainly triggered by infection or autoimmune process. MALT lymphoma is frequently detected in the gastrointestinal tract. As the causal relationship between Helicobacter pylori (H. pylori) infection and gastric MALT lymphoma, it was well-established that early-stage gastric MALT lymphoma could be cured by H. pylori eradication, and about 50–95% of cases achieved complete response with anti-H. pylori treatment. Compared to the stomach which is the most involved site due to the high prevalence of H. pylori infection, the colorectum is rarely affected. Primary rectal MALT lymphoma is a rare malignancy, and there are no specific therapeutic strategies so far. Here we report a case of rectal MALT lymphoma successfully resected by endoscopic submucosal dissection (ESD). ESD serves as a novel strategy to cure small localized rectal MALT lymphomas to avoid unnecessary surgery or chemo-radiotherapy.

Laterally spreading tumor-like primary rectal mucosa-associated lymphoid tissue lymphoma: A case report

BACKGROUND

Colorectal mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease, and only a few cases have been reported to date. It has no specific clinical presentations and shows various endoscopic appearances. There is no uniform consensus on its treatment. With the advancement of endoscopic technology, endoscopic treatment has achieved better results in individual case reports of early-stage patients.

CASE SUMMARY

We report a case of rectal MALT in a 57-year-old Chinese man with no symptoms who received endoscopy as part of a routine physical examination, which incidentally found a 25 mm × 20 mm, laterally spreading tumor (LST)-like elevated lesion in the rectum. Therefore, he was referred to our hospital for further endoscopic treatment. Complete and curable removal of the tumor was performed by endoscopic submucosal dissection. We observed enlarged and dilated branch-like vessels similar to those of gastric MALT lymphoma on magnifying endoscopy with narrow-band imaging. And immunopathological staining showed hyperplastic capillaries in the mucosa. Histopathological findings revealed diffusely hyperplastic lymphoid tissue in the lamina propria, with a visible lymphoid follicle structure surrounded by a large number of diffusely infiltrated lymphoid cells that had a relatively simple morphology and clear cytoplasm. In addition, immunohistochemical analysis suggested strongly positive expression for CD20 and Bcl-2. Gene rearrangement results showed positivity for IGH-A, IGH-C, IGK-B, and IGL. Taking all the above findings together, we arrived at a diagnosis of extranodal marginal zone B-cell lymphoma of MALT lymphoma. Positron emission tomography-computed tomography examination showed no other lesions involved. The patient will be followed by periodic endoscopic observation.

CONCLUSION

In conclusion, we report a case of rectal MALT with an LST-like appearance treated by endoscopic submucosal dissection. Further studies will be needed to explore the clinical behavior, endoscopic appearance, and treatment of rectal MALT.

The Pillow Sign: Is It Always Benign?

Mucosa-associated lymphoid tissue (MALT) lymphoma is classically found in the stomach; however, in less common, cases can be found in extragastric locations. Colonic MALTomas are exceedingly rare and comprise a small group of extragastric cases. There is no standardized approach for optimal management of this disease. We report a case of a colonic MALT lymphoma found on colonoscopy that demonstrated the pillow sign and appearance of a benign lipoma. Despite antimicrobial and endoscopic therapy, the malignancy reoccurred in a patient with chronic hepatitis B, thereby precluding one of the mainstays of treatment, rituximab, until viral eradication.

Synchronous colonic mucosa-associated lymphoid tissue lymphoma found after surgery for adenocarcinoma: A case report and review of literature

BACKGROUND

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.

CASE SUMMARY

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.

CONCLUSION

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.

MALT lymphoma of the colon: a clinicopathological review

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) occurs in approximately 9% of non-Hodgkin B cell lymphoma. However, it occurs only rarely within the colon. The presentation is often asymptomatic, and can have multiple endoscopic appearances, including a single or multinodular polypoid lesion. Furthermore, small biopsies can make histological evaluation challenging. The 2016 WHO classification update includes many molecular features of entities and expands the differential diagnosis of lymphoid lesions of the colon. In addition to immunohistochemistry, molecular methods may be tempting to use for small difficult cases. Furthermore, treatment approaches are varied for this entity, and not well studied. Therefore, an updated review on MALT lymphoma of the colon is needed.

Successful Endoscopic Resection of Mucosa-Associated Lymphoid Tissue Lymphoma of the Colon

Mucosa-associated lymphoid tissue lymphomas are the most common form of primary malignant gastrointestinal lymphoma. Although typically found in the stomach, extragastric locations have been described, in rare cases, the colon. The optimal management of these neoplasms remains uncertain and limited largely to small retrospective series or case reports. We report a patient with a colonic mucosa-associated lymphoid tissue lymphoma identified during a routine screening colonoscopy which was removed endoscopically without any adjuvant antimicrobial therapy, chemotherapy, or radiation therapy. She remained disease-free after the 1-year follow-up, providing support to potential endoscopic therapy in appropriately selected patients.

Clinical features, treatment and outcomes of colorectal mucosa-associated lymphoid tissue (MALT) lymphoma: literature reviews published in English between 1993 and 2017

Background

Colorectal mucosa-associated lymphoid tissue (MALT) lymphoma (cMALToma) is rare and comprises only 2.5% of the MALT lymphomas. Its etiology and treatment have not been well established. The aim of this systematic literature review was to try to characterize cMALToma and analyze the risk factors for treatment failure with various therapeutic strategies.

Methods

We retrospectively reviewed 50 case reports from 1993 to 2017 through a PubMed search of English medical literature, describing cMALToma. We included 67 patients from previous case reports and we added 6 patients treated for cMALToma in our multicenter institutes. Risk factor analysis was done for treatment failure, defined as remission failure and recurrence.

Results

Of 73 patients diagnosed with cMALToma, tumors were located in 54 patients (74.0%) in the rectum, in 10 patients (13.6%) in the right colon, in 3 patients (4.1%) in the transverse colon, and in 6 patients (8.2%) in the sigmoid colon. In first-line treatment, patients achieved complete remission (CR) with surgery (18/19 cases), local resection (18/19 cases), chemotherapy (12/13 cases), radiation therapy (4/5 cases), antibiotics therapy including Helicobacter pylori eradication (12/15 cases), and no treatment (1/2 cases). Among these, eight cases (10.9%) needed second-line treatment, and there was overall remission failure in 3 cases (4.1%). Of the remaining 70 patients with CR, the tumor recurred in 5 patients (6.8%). The multivariable analysis showed that male sex, multiple tumors, and first-line treatment failure were significantly related to treatment failure (p=0.03, p=0.05, p=0.03, respectively).

Conclusion

CR of primary cMALToma was achieved using various therapeutic strategies. First-line treatment failure and multiple tumors were associated with treatment failure, although the numbers of cases that failed are too small to draw definitive conclusions.

Mass-forming mucosa-associated lymphoid tissue lymphoma of the cecum treated by laparoscopy-assisted bowel resection

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.

Simultaneous Occurrence of Colonic Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma (MALToma) and Lung Cancer

Colonic MALToma accounts for 2.5% of all MALTomas. MALToma can be associated with certain chronic infections, autoimmune disorders, Waldenstrom's macroglobulinemia, and old age. Synchronous MALTomas can occur in multiple organs. Simultaneous occurrence of colonic MALToma and colon cancer has been reported. A case of colonic MALToma and lung cancer is described here.

Colorectal Lymphoma: A Review

Non-Hodgkin lymphoma (NHL) that primarily involves the colon is rare and should be distinguished from the more common systemic nodal lymphoma. It has unique clinical expectations and management consideration. Different histologic subtypes of NHL involve the colon, which varies in the clinical behavior and likelihood of obtaining durable remissions with treatment. This article will review the current understanding of the different histologic subtypes of primary colorectal lymphoma and propose management algorithms.

Synchronous MALT lymphoma of the colon and stomach and regression after eradication of Strongyloides stercoralis and Helicobacter pylori

Mucosa-associated lymphoid tissue (MALT) is vital for host immunological surveillance against pathogens. MALT lymphoma, also known as extranodal marginal zone B cell lymphoma, is a non-Hodgkin's lymphoma subtype that predominantly arises in the gastrointestinal tract. Chronic Helicobacter pylori (H. pylori) infection is a common cause of gastric MALT lymphoma, although other infections are reported in association with extragastric MALT lymphomas. To our knowledge, here we report the first case of synchronous MALT lymphomas of the colon and stomach in the presence of Strongyloides stercoralis and H. pylori infections that resolved after eradication of both organisms.

Endoscopic features and clinical outcomes of colorectal mucosa-associated lymphoid tissue lymphoma

BACKGROUND AND AIMS

Colorectal mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease. The purpose of this study was to investigate the clinical and endoscopic features of colorectal MALT lymphoma.

METHODS

Patients diagnosed with colorectal MALT lymphoma at Asan Medical Center from 2002 to 2016 were eligible. Medical records were reviewed to investigate clinical features and treatment outcomes. Endoscopic pictures were assessed to characterize the endoscopic features of colorectal MALT lymphoma.

RESULTS

A total of 51 patients were enrolled. The median age was 60 years (interquartile range, 55-71), and 21 (41%) were men. Twenty-six patients (51%) were asymptomatic. Forty-four patients (86%) were in early disease stages, namely Lugano stages I, II, and II_E. Endoscopic appearances were classified as 4 distinct types: subepithelial tumor type (26 patients, 51%), polyposis type (10 patients, 20%), epithelial mass type (7 patients, 14%), and ileitis type (8 patients, 16%). The rectum (20 patients, 39%) was the most common location, followed by the ileocecal area (15 patients, 30%). An initial endoscopic impression of lymphoma was made in only 7 patients. Forceps biopsy sampling as the initial tissue acquisition method could histologically diagnose MALT lymphoma in 28 of 35 patients (80%). Polypectomy as the initial histologic diagnosis could diagnose MALT lymphoma in 16 of 16 patients. Progression-free and overall survival rates at 5 years were 92% and 94%, respectively.

CONCLUSIONS

Colorectal MALT lymphomas show various endoscopic appearances, complicating the endoscopic suspicion of colorectal MALT lymphoma. The prognosis of colorectal MALT lymphoma was excellent.

A Rare Case of MALT Lymphoma Underlying Ileocecal Intussusception

Intussusception is an extremely rare diagnosis in adults, with an etiologic process identified in the majority of cases. The authors describe an unusual case of mucosa-associated lymphoid tissue (MALT) lymphoma as the underlying cause of ileocecal intussusception in an elderly woman. The patient presented with complaints of abdominal pain of variable intensity that had increased in severity over the past several months. A contrast-enhanced computed tomographic scan revealed evidence of ileocecal intussusception, and a subsequent exploratory laparotomy revealed high-grade bowel obstruction. Early recognition of intussusception is critical to appropriate management and resolution.

Radiotherapy for mucosa-associated lymphoid tissue (MALT) lymphoma of the rectum: a case report

Extra-nodal mucosa-associated lymphoid tissue (MALT) lymphoma is frequently involved with the upper gastrointestinal tract, but rarely involved with the rectum. We report a case of rectal MALT lymphoma treated by radiotherapy (RT) alone. A 74-year-old woman with lower abdominal pain was diagnosed with MALT lymphoma by endoscopic mucosal resection (EMR). She was diagnosed as stage IE (Ann Arbor) MALT lymphoma by diagnostic work-up and review of EMR specimens. Definitive RT was performed with curative intent, totaling 30 Gy in 15 fractions. Complete response was confirmed by colonoscopy after RT with no progression observed at 5 years. Definitive RT is effective for rectal MALT lymphoma.

Mucosa-Associated Lymphoid-Tissue Lymphoma of the Cecum and Rectum: A Case Report

A colonic mucosa-associated lymphoid-tissue (MALT) lymphoma is relatively rare compared to lymphomas of the stomach or small intestine. We present a case of a MALT lymphoma in the cecum and rectum found during screening colonoscopy. A 54-year-old female, who had undergone right-breast-conserving surgery with axillary dissection due to an invasive ductal carcinoma and a left-breast excisional biopsy due to microcalcification following adjuvant chemoradiation therapy 3 years earlier, was found to have 3-mm-sized smooth elevated lesions in both the cecum and rectum. No pathologic lesion or lymphadenopathy was found at any other site, but chronic gastritis negative for Helicobacter pylori infection was found. The polyps were removed by using an endoscopic biopsy and revealed an extra nodal marginal zone B-cell MALT lymphoma, showing positive for CD3 and CD20 by immunohistochemical staining. The patient underwent close observation without any additional treatment and has shown no evidence of recurrence as of her last visit.

Mucosa-Associated Lymphoid Tissue Lymphoma of the Sigmoid Colon Discovered on Routine Screening Colonoscopy in Patient with Hepatitis C and Helicobacter pylori Infection

Mucosa-associated lymphoid tissue (MALT) lymphoma is predominantly found in the stomach. Rarely, it is found in the proximal colon and even less so in the sigmoid colon. We present a rare case of primary sigmoid colon MALT lymphoma in a patient with concomitant Helicobacter pylori and hepatitis C infection. We also review current imaging, staging, and therapeutic modalities. To our knowledge, this is the first sigmoid colon MALT lymphoma reported in the United States.

Concurrent colonic mucosa-associated lymphoid tissue lymphoma and adenoma diagnosed after a positive fecal occult blood test: a case report

Background

Colonic lymphoma is an uncommon presentation of extranodal lymphoma. Colonic mucosa-associated lymphoid tissue lymphoma is a different entity from gastric mucosa-associated lymphoid tissue lymphoma, and very rare. The presentation and management of colonic mucosa-associated lymphoid tissue are highly variable in the literature.

Case presentation

We report the case of a 59-year-old Taiwanese man who underwent a colonoscopy after a positive test for fecal occult blood. His past history included hypertension and hyperthyroidism. The colonoscopy revealed an adenomatous polyp and mucosa-associated lymphoid tissue lymphoma. We successfully performed a polypectomy and endoscopic mucosal resection. The lymphoma was staged according to the Ann Arbor system modified by Musshoff as E-I. Our patient showed no lymphoma recurrence over a 3-year follow-up.

Conclusions

Endoscopic mucosal resection for colonic mucosa-associated lymphoid tissue lymphoma without disseminated disease may be feasible. We successfully used colonoscopic treatment without adjuvant therapy to treat early-stage pathogen-free colonic mucosa-associated lymphoid tissue lymphoma.

Regression of Cecal MALT Lymphoma after Antibiotic Treatment in a Patient with Helicobacter pylori Infection

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.

Colonic mucosa-associated lymphoid tissue lymphoma identified by chromoendoscopy

Colonic mucosa-associated lymphoid tissue (MALT) lymphomas are a rare occurrence and the definitive treatment has not been established. Solitary or multiple, elevated or polypoid lesions are the usual appearances of MALT lymphoma in the large intestine and sometimes the surface may reveal abnormal vascularity. Herein, we report a case of MALT lymphoma and review the relevant literature. Upon colonoscopy, a suspected pathologic lesion was observed in the proximal transverse colon. The lesion could be distinguished more prominently after using narrow-band imaging mode and indigo carmine-dye spraying chromoendoscopy. Histopathologic examination of this biopsy specimen revealed lymphoepithelial lesions with diffuse proliferation of atypical lymphoid cells effacing the glandular architecture and centrocyte-like cells infiltrating the lamina propria. Immunohistochemical analyses showed that tumor cells were positive for CD20 and Bcl-2e, and negative for CD10, CD23, and Bcl-6. According to Ann-Arbor staging system, the patient had stage II_E. A partial colectomy with dissection of the paracolic lymph nodes was performed. Until now, there is no recurrence of lymphoma at follow-up.