Skip Navigation
Skip to contents

Clin Endosc : Clinical Endoscopy

Search
Advanced Search
OPEN ACCESS
mobile search button mobile menu button

Articles

Page Path
HOME > Clin Endosc > Volume 58(3); 2025 > Article
CME for
KSGE members
Boost Your Learning with Quiz A 12 mm-sized rectal subepithelial tumor: uncommon, but one you must know
Seong-Jung Kimorcid, Jun Leeorcid
Clinical Endoscopy 2025;58(3):485-487.
DOI: https://doi.org/10.5946/ce.2025.068
Published online: April 30, 2025

Department of Internal Medicine, Chosun University College of Medicine, Gwangju, Korea

Correspondence: Seong-Jung Kim Department of Internal Medicine, Chosun University Hospital, 365 Pilmun-daero, Dong-gu, Gwangju 61453, Korea E-mail: ygegh@hanmail.net
• Received: February 28, 2025   • Revised: March 12, 2025   • Accepted: March 13, 2025

© 2025 Korean Society of Gastrointestinal Endoscopy

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

  • 856 Views
  • 75 Download
prev next
Full Article

Download PDF Download PDF

A 65-year-old woman presented with a rectal subepithelial lesion, approximately 1 cm in size, that was incidentally detected during a screening colonoscopy. She had hypertension but no history of alcohol consumption or smoking. At presentation, she reported no symptoms, including abdominal pain or diarrhea, and had experienced no associated weight loss. Initial endoscopic ultrasonography revealed a subepithelial tumor (SET) in the rectum, located approximately 4 cm proximal to the anal verge and measuring approximately 1 cm in size. The lesion exhibited a whitish, rounded appearance with a slightly depressed center, and was covered by mildly hyperemic mucosa. The lesion was firm and showed no signs of rolling. Observations using a miniprobe (12 MHz, UM-2R; Olympus) revealed a hypoechoic, homogeneous, and well-circumscribed mass in the second layer, measuring approximately 10.6×7.6 mm (Fig. 1). Endoscopic submucosal dissection was subsequently performed in an attempt at endoscopic resection. Following submucosal fluid injection to lift the lesion, dissection was performed using a needle knife, resulting in an en bloc resection. The final pathological specimen measured 12×10 mm, and histopathological findings are shown in Figure 2. What is the most probable diagnosis?
Histopathological evaluation using hematoxylin and eosin staining revealed diffuse and dense infiltration of small lymphocytes and lymphoepithelial lesions in the colonic mucosa (Fig. 2A, B). Immunohistochemical staining showed that CD20 and bcl-2 were positive, while CD3 and bcl-6 were negative, confirming the diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma (Fig. 2C–F). Esophagogastroduodenoscopy, computed tomography, and bone marrow biopsy were performed for staging, and the final diagnosis was stage I MALT lymphoma.
Colorectal MALT lymphomas constitute approximately 1% to 2.5% of all MALT lymphomas and are predominantly observed in the stomach within the gastrointestinal tract, while their occurrence in the colon and rectum is rare.1 This condition follows a relatively indolent course, with 5-year survival rates exceeding 90% following appropriate treatment.2 Due to its rarity, a standardized treatment protocol for colorectal MALT lymphoma has yet to be established.
Colorectal MALT lymphoma is most often detected during screening colonoscopy and diagnosed via biopsy. Endoscopic findings vary widely, ranging from SET, as seen in this case, to more extensive lesions.2,3 These lesions can present as single or multiple lesions, and while most patients are asymptomatic, they may also experience symptoms including abdominal pain, hematochezia, or bowel obstruction.4
Treatment for colorectal MALT lymphoma includes endoscopic resection, chemotherapy, rituximab monotherapy, surgical resection, radiation therapy, and Helicobacter pylori eradication.2,5-9 Although the optimal treatment remains inconclusive, surgery tends to be favored for symptomatic disease.2,8 Considering that colorectal MALT lymphoma is a malignant tumor, selecting an appropriate initial treatment modality is critical for achieving curative outcomes. Won et al.2 analyzed 50 case reports encompassing 73 patients with colorectal MALT lymphoma and reported that failure of first-line treatment and the presence of multiple tumors were significant risk factors for treatment failure.
If the disease is focal at an early stage and presents as a single lesion, endoscopic resection can serve as an excellent treatment modality.6,10 Endoscopic resection, with its low procedural risk and minimally invasive nature, plays an important role in organ preservation and maintenance of the patient's quality of life. Endoscopic resection may thus be an effective curative treatment for localized lesions. However, caution is advised when the lymphoma surface is accompanied by fine vascular structures and erythema, which can obscure the lesion margins. In such cases, a slightly wider incision than the estimated lesion size is recommended to achieve complete resection.
The patient in this case had been diagnosed with stage I single rectal MALT lymphoma, and following successful endoscopic resection with rectal preservation, showed no recurrence up to four years.
Fig. 1.
Colonoscopy revealed a subepithelial lesion in the rectum that measured about 1 cm in size. (A) Endoscopic ultrasonography revealed a hypoechoic, homogeneous, well-circumscribed mass in the second layer, measuring approximately 10.6×7.6 mm. (B) Endoscopic submucosal dissection was performed to remove the lesion. (C, D) The lesion was resected en bloc, and the final size was 12×10 mm.
ce-2025-068f1.jpg
Fig. 2.
Hematoxylin and eosin staining revealed a diffuse and dense infiltration of small-sized lymphocytes and a lymphoepithelial lesion in the colonic mucosa (A, ×40) (B, ×100). Immunohistochemical staining showed that CD20 (C, ×40) and bcl-2 (E, ×40) was positive, while CD3 (D, ×40) and bcl-6 (F, ×40) were negative.
ce-2025-068f2.jpg
  • 1. Chen PH, Lin YM, Yen HH. Primary mucosa-associated lymphoid tissue lymphoma of the colon. Clin Gastroenterol Hepatol 2011;9:e74–e75.ArticlePubMed
  • 2. Won JH, Kim SM, Kim JW, et al. Clinical features, treatment and outcomes of colorectal mucosa-associated lymphoid tissue (MALT) lymphoma: literature reviews published in English between 1993 and 2017. Cancer Manag Res 2019;11:8577–8587.Article
  • 3. Lee SH, Kang SB. A focally flat-elevated lesion in distal transverse colon resembling a subepithelial tumor. Clin Endosc 2023;56:388–390.ArticlePubMedPMCPDF
  • 4. Piotrowski R, Kramer R, Kamal A. Image of the month. Extranodal marginal zone B-cell (mucosa-associated lymphoid tissue) lymphoma of the colon presenting as an obstructing mass. Clin Gastroenterol Hepatol 2008;6:e18–e19.ArticlePubMed
  • 5. Akasaka R, Chiba T, Dutta AK, et al. Colonic mucosa-associated lymphoid tissue lymphoma. Case Rep Gastroenterol 2012;6:569–575.ArticlePubMedPMC
  • 6. Choi J. Successful endoscopic resection of residual colonic mucosa-associated lymphoid tissue lymphoma after polypectomy. Clin Endosc 2021;54:759–762.ArticlePubMedPMCPDF
  • 7. Conconi A, Martinelli G, Thiéblemont C, et al. Clinical activity of rituximab in extranodal marginal zone B-cell lymphoma of MALT type. Blood 2003;102:2741–2745.ArticlePubMed
  • 8. Raderer M, Pfeffel F, Pohl G, et al. Regression of colonic low grade B cell lymphoma of the mucosa associated lymphoid tissue type after eradication of Helicobacter pylori. Gut 2000;46:133–135.ArticlePubMedPMC
  • 9. Jeon MK, So H, Huh J, et al. Endoscopic features and clinical outcomes of colorectal mucosa-associated lymphoid tissue lymphoma. Gastrointest Endosc 2018;87:529–539.ArticlePubMed
  • 10. Kim WS, Joo MK. Advancements in endoscopic resection of subepithelial tumors: toward safer, recurrence-free techniques. 2025;58:256–258.ArticlePubMedPDF

Figure & Data

REFERENCES

    Citations

    Citations to this article as recorded by  

      • PubReader PubReader
      • ePub LinkePub Link
      • Cite
        CITE
        export Copy Download
        Close
        Download Citation
        Download a citation file in RIS format that can be imported by all major citation management software, including EndNote, ProCite, RefWorks, and Reference Manager.
        Format:
        • RIS — For EndNote, ProCite, RefWorks, and most other reference management software
        • BibTeX — For JabRef, BibDesk, and other BibTeX-specific software
        Include:
        • Citation for the content below
        A 12 mm-sized rectal subepithelial tumor: uncommon, but one you must know
        Clin Endosc. 2025;58(3):485-487.   Published online April 30, 2025
        DOI: https://doi.org/10.5946/ce.2025.068
        Close
      • XML DownloadXML Download
      Figure
      • 0
      • 1
      A 12 mm-sized rectal subepithelial tumor: uncommon, but one you must know
      Image Image
      Fig. 1. Colonoscopy revealed a subepithelial lesion in the rectum that measured about 1 cm in size. (A) Endoscopic ultrasonography revealed a hypoechoic, homogeneous, well-circumscribed mass in the second layer, measuring approximately 10.6×7.6 mm. (B) Endoscopic submucosal dissection was performed to remove the lesion. (C, D) The lesion was resected en bloc, and the final size was 12×10 mm.
      Fig. 2. Hematoxylin and eosin staining revealed a diffuse and dense infiltration of small-sized lymphocytes and a lymphoepithelial lesion in the colonic mucosa (A, ×40) (B, ×100). Immunohistochemical staining showed that CD20 (C, ×40) and bcl-2 (E, ×40) was positive, while CD3 (D, ×40) and bcl-6 (F, ×40) were negative.

      Fig. 1.

      Fig. 2.

      A 12 mm-sized rectal subepithelial tumor: uncommon, but one you must know
      Clin Endosc : Clinical Endoscopy Twitter Facebook
      © Korean Society of Gastrointestinal Endoscopy.
      Close layer
      TOP