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

Abstract

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.

Unusual rectal polyp

“…Tree-like-appearance blood vessels observed on magnified NBI have been mentioned in colon MALT lymphoma. 4 In this case, Indogocarmine chromoendoscopy showed irregular mucosal surface pattern, not correlated with EUS finding. NBI magnifying colonoscopy showed Japan NBI Expert Team classification type 3 with branch-like microvascular pattern was the high spot and gave us the hint of colon MALToma.…”

“…Image‐enhanced colonoscopy was useful for observed microstructure of flatten lesion. Tree‐like‐appearance blood vessels observed on magnified NBI have been mentioned in colon MALT lymphoma 4 . In this case, Indogocarmine chromoendoscopy showed irregular mucosal surface pattern, not correlated with EUS finding.…”

Multiple Colorectal Mucosa-Associated Lymphoid Tissue Lymphoma Successfully Treated with Chemotherapy

“…According to the Japanese practical guidelines for hematological malignancies (2018, revised version) [7], careful follow-up without therapy, irradiation, and surgical resection are recommended for the treatment of extragastric MALT lymphoma in the localized stage. As local treatments, the effectiveness of surgical or endoscopic tumor resection and irradiation has been reported for primary colorectal MALT lymphoma [8, 9]; however, follow-up without treatment may be acceptable when patients are asymptomatic. As a drug treatment, the usefulness of H .…”