Endoscopic Evaluation of a Gastric Mass Mimicking a Subepithelial Tumor

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Korean J Helicobacter Up Gastrointest Res. 2026;26(2):255-256

Publication date (electronic) : 2026 June 8

doi : https://doi.org/10.7704/kjhugr.2026.0022

Younghee Choe, Byung-Wook Kim

Division of Gastroenterology and Hepatology, Department of Internal Medicine, Incheon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea

Corresponding author Younghee Choe, MD, PhD Department of Internal Medicine, Incheon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, 56 Dongsu-ro, Bupyeong-gu, Incheon 21431, Korea E-mail: ychoe@catholic.ac.kr

Received 2026 March 20; Revised 2026 May 11; Accepted 2026 May 18.

Question

A 56-year-old woman presented with a suspected mass during an esophagogastroduodenoscopy (EGD). She had no history of taking any specific medications other than for hypertension. Physical examination revealed no specific findings, and blood tests showed no abnormalities.

During the EGD, a 3 cm mass was observed in the lesser curvature of the lower body (Fig. 1). There was no rolling sign when prodded with forceps. What is the suspected diagnosis?

Fig. 1.

Endoscopic view of the lower body. A 3 cm subepithelial tumor- like lesion is visible along the lesser curvature.

Answer

The diagnosis is gastric extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma).

An additional endoscopic ultrasound was performed, and the lesion was in the muscularis mucosae (MM) (Fig. 2). Histological examination confirmed MALT lymphoma, and since the lesion was in the MM layer, sufficient tissue could be obtained via bite-on-bite biopsy. Helicobacter pylori was confirmed negative, and no BIRC3/MALT1 t(11:18) translocation was observed. The patient underwent radiation therapy on the stomach (30 Gy/15 fx), and after radiation therapy, the affected area was completely free of lesions (Fig. 3). The patient was Helicobacter pylori negative and had no t(11;18). This finding was associated with reduced responsiveness to eradication therapy, so radiation therapy was selected as the primary treatment modality.

Fig. 2.

Endoscopic ultrasound image. A hypoechoic mass is localized within the muscularis mucosa layer (arrow).

Fig. 3.

Follow-up endoscopy one year post-radiation therapy. Complete resolution of the previously noted subepithelial lesion.

MALT lymphoma is a low-grade B-cell lymphoma that frequently occurs in the stomach. It is considered a representative example of antigen-induced malignancy due to its association with infectious agents such as Helicobacter pylori and Chlamydophila psittaci, as well as autoimmune diseases [1]. It generally progresses more slowly than other lymphomas and can occur anywhere in the body, not just the digestive tract, with the stomach being the most affected organ. It can be caused by various genetic abnormalities such as t(11;18)(q12;q21), t(1;14)(p22;q32), and t(14;18)(q32;q21) translocations, as well as by chronic inflammation [2,3].

Approximately 80%–90% of gastric MALT lymphomas are associated with Helicobacter pylori infection, so eradication therapy is selected as the primary treatment, and treatment success is observed in about 80% of cases after successful eradication [4]. However, the etiology of Helicobacter pylori-negative MALT lymphoma remains unclear, although other microorganisms may be involved [5].

Gastric MALT lymphomas exhibit diverse appearances on endoscopy and are therefore also referred to as “characterized by a lack of endoscopic features.” It may appear as ulcers, raised nodules, or diffuse lesions; it can also present as multiple ulcer scars or as a mass, as seen in the patient above. Generally, there are no symptoms, so the diagnosis is made via EGD. Definitive diagnosis hinges upon histopathological evaluation via endoscopic biopsy. Since it can sometimes resemble simple gastritis, repeated biopsies are crucial if suspected.

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