MALT lymphoma of the rectum, presenting with rectal prolapsus: a case report

A Rare Case of Primary Extra-Nodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue (MALT) in the Rectum

Mucosa-associated lymphoid tissue (MALT) is a unique clinical condition that can manifest in different anatomic locations. In the gastrointestinal tract, it is typically seen in the stomach but is less commonly found in other sites. There have been a few cases in the literature in which primary MALT lymphoma is found in the rectum. We describe a case of a 63-year-old male who presented with rectal pain and bleeding. Colonoscopy revealed a rectal mass, which was excised with a trans-anal approach. Histopathological examination of the biopsy specimen was significant for MALT lymphoma. Therefore, the patient underwent radiation therapy followed by repeat colonoscopies to monitor disease recurrence.

Endoscopic mucosal resection and cure for rectal mucosa-associated lymphoid tissue lymphoma

We present a case of Helicobacter pylori-negative rectal mucosa-associated lymphoid tissue (MALT) lymphoma found on colonoscopy done for colorectal cancer screening. The lesion was successfully removed with endoscopic mucosal resection alone, without concomitant antibacterial treatment. On surveillance exams, the patient has had a 5-year disease-free survival. While prior reports highlight use of multiple modalities, this is the only case we are aware of in which treatment with endoscopic mucosal resection alone without antimicrobial therapy led to disease-free survival at 5 years.

Anti-Helicobacter Pylori Therapy in Primary MALT Lymphoma of Rectum

Primary rectal MALT lymphoma is a very rare entity among extranodal MALT lymphomas and its therapeutic management has not been standardized. Different approaches including surgery, chemotherapy and radiotherapy have been proposed in the last decades. There have been reports on complete responses after anti-Helicobacter pylori therapy, also in patients without serological or histological evidence of Helicobacter pylori infection. In our patient we obtained a complete response with anti-Helicobacter pylori therapy and a disease-free survival of 34 months. Endoscopic ultrasound was useful for diagnosis and follow-up. Although the mechanisms that determined this response remain a matter of debate, anti-Helicobacter pylori therapy can be considered as first-line therapy in stage IE, nonbulky primary rectal MALT lymphoma. Endoscopic ultrasound could play a relevant role in the management of this rare condition.

Mucosa-associated lymphoid tissue (MALT) variant of primary rectal lymphoma: a review of the English literature

PURPOSE

Primary rectal lymphoma (PRL) is the third most common cause of rectal cancer following adenocarcinoma (90-95 %) and carcinoid (5 %). The most common variant of PRL is the mucosa-associated lymphoid tissue (MALT) type. To date, no study has been able to recommend an optimal treatment algorithm for this rare disease. The aim of our study was to review the English literature on primary rectal MALT lymphoma.

METHODS

A review of the English literature was conducted to identify articles describing the MALT variant of PRL.

RESULTS

Fifty-one cases were identified. A complete response was achieved in 12 of 19 cases treated with Helicobacter pylori eradication therapy, 5 of 6 with radiation, 2 of 4 cases with chemotherapy, 2 of 4 with endoscopic resection, 6 of 8 cases with surgical resection, and all 8 with combination therapies. Cases failing initial therapies were responsive to various second-line treatments. Two cases spontaneously regressed with observation alone.

CONCLUSION

Complete regression of primary rectal MALT lymphoma was achieved using various therapeutic strategies, although the numbers of different treatment modalities are too small to draw definitive conclusions.

Role of Helicobacter pylori in gastric mucosa-associated lymphoid tissue lymphomas

Mucosa-associated lymphoid tissue (MALT) lymphoma is an indolent extranodal marginal zone B-cell lymphoma, originating in acquired MALT that is induced in mucosal barriers as part of a normal adaptive immune response to a chronic immunoinflammatory stimulus, most notably chronic infection by Helicobacter pylori (H. pylori). This antigenic stimulation initially leads to lymphoid hyperplasia; the acquisition of additional genetic aberrations culminates in the activation of intracellular survival pathways, with disease progression due to proliferation and resistance to apoptosis, and the emergence of a malignant clone. There are descriptions of MALT lymphomas affecting practically every organ and system, with a marked geographic variability partially attributable to the epidemiology of the underlying risk factors; nevertheless, the digestive system (and predominantly the stomach) is the most frequently involved location, reflecting the gastrointestinal tract’s unique characteristics of contact with foreign antigens, high mucosal permeability, large extension and intrinsic lymphoid system. While early-stage gastric MALT lymphoma can frequently regress after the therapeutic reversal of the chronic immune stimulus through antibiotic eradication of H. pylori infection, the presence of immortalizing genetic abnormalities, of advanced disease or of eradication-refractoriness requires a more aggressive approach which is, presently, not consensual. The fact that MALT lymphomas are rare neoplasms, with a worldwide incidence of 1-1.5 cases per 10⁵ population, per year, limits the ease of accrual of representative series of patients for robust clinical trials that could sustain informed evidence-based therapeutic decisions to optimize the quality of patient care.