Primary Mucosa-associated Lymphoid Tissue (MALT) Lymphoma Occurring in the Rectum: A Case Report and Review of the Literature

Abstract

The primary extranodal B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) is a distinct clinical pathologic entity that develops in diverse anatomic locations such as the stomach, salivary gland, thyroid, lung, and breast; however, colorectal involvement is rare. To the best of our knowledge, only 30 cases of primary rectal MALT lymphoma have been published in the English language literature, mostly from Japan. A single case has been reported from the US before this report. The most common symptoms ranged from asymptomatic to occult or gross gastrointestinal bleeding. Simultaneous involvement of the cecum or colon was seen in 20% of the patients. Ninety percent of the patients were classified as low grade, Stage 1 at the time of diagnosis. Polypoid lesions were 10-fold more common than ulcerative lesions. Seven patients were reported to have H pylori in the stomach. The majority of the patients underwent surgical or endoscopic resection as a cure; however, controversy exists with regards to antibiotic treatment or observation alone because of unknown etiopathogenesis. Infection with microorganisms other than H pylori has been postulated in the development of rectal MALT lymphoma; however, this hypothesis remains unproven. The overall prognosis of rectal MALT lymphoma appears favorable; however, long-term follow-up data is lacking. Therefore, periodic clinical monitoring should be done in these patients.

A Case of Rectal Mucosa-associated Lymphoid Tissue Lymphoma Diagnosed by Endoscopic Unroofing Technique

“…10 In the present case, H. pylori infection was not confirmed. Thus, the eradication of H. pylori was not attempted.…”

“…8,9 Most MALT lymphomas arise from the gastrointestinal organs. 10 However, it is able to develop in diverse anatomic locations such as the salivary gland, thyroid, lung and breast. 9,10 A relationship between gastric MALT lymphoma and Helicobacter pylori (H. pylori) infection has been clearly established, and low grade gastric MALT lymphoma is known to regress after eradication of H. pylori.…”

“…10 EUS could be applied to the diagnosis and recognition of subepithelial tumor, but it is possible that even small benign subepithelial tumors suspected on EUS would be reported as malignancy after resection. The unroofing technique is not commonly used, however,…”

Regression of Cecal MALT Lymphoma after Antibiotic Treatment in a Patient with <i>Helicobacter pylori</i> Infection

“…On the other hand, a standard treatment protocol for colonic MALT lymphoma has yet to be established because of the rarity of the disease and lack of an established etiological cause. Treatments for colonic MALT lymphoma include surgery, chemotherapy, radiotherapy and endoscopic resection (13). In 1997, Matsumoto et al reported the first case of rectal MALT lymphoma regression after H. pylori eradication therapy (14).…”

Complete Histopathological Disappearance of Rectal Malt Lymphoma after Eradication of Helicobacter pylori Confirmed by ESD

“…Primary rectal MALT lymphomas are even rarer, therefore, their treatment has not been well-studied and there is no established standard therapy. Recent reports have documented the disappearance of rectal MALT lymphomas following H. pylori eradication therapy [5][6][7][8][9][10][11][12][13][14][15][16], however, this remains controversial, and it is yet to be clarified whether complete histological disappearance of rectal MALT lymphomas can be achieved following H.pylori eradiation therapy, since all previous reports are based on evaluation of only the endoscopic findings. We performed ESD and evaluated the disappearance of the lesions histopathologically.…”