From the Guidelines
MALT lymphoma is a type of non-Hodgkin lymphoma that represents 7% of all non-Hodgkin’s lymphomas and can arise at any extranodal site, with at least one-third presenting as a primary gastric lymphoma. This cancer typically forms in the stomach but can also occur in other areas such as the lungs, thyroid, salivary glands, eyes, or skin. MALT lymphoma is often linked to chronic inflammation caused by infections, particularly Helicobacter pylori (H. pylori) in gastric MALT lymphoma, as noted in the study published in the Annals of Oncology 1.
Key Characteristics of MALT Lymphoma
- Represents 7% of all non-Hodgkin’s lymphomas
- Can arise at any extranodal site
- At least one-third present as a primary gastric lymphoma
- Often linked to chronic inflammation caused by infections, such as H. pylori
Diagnosis and Treatment
The diagnosis of gastric MALT lymphoma is based on the histopathologic evaluation of gastric biopsies, and the presence of active H. pylori infection must be determined by histochemistry or alternatively urea breath test 1. Eradication of H. pylori with antibiotics should be employed as the sole initial treatment of localized H. pylori-positive gastric MALT lymphoma, with any of the highly effective anti-Helicobacter antibiotic regimens proposed being used. In case of unsuccessful H. pylori eradication, second-line therapy should be attempted with alternative triple- or quadruple-therapy regimens of proton-pump inhibitor plus antibiotics.
Treatment Options
- Eradication of H. pylori with antibiotics for localized H. pylori-positive gastric MALT lymphoma
- Second-line therapy with alternative triple- or quadruple-therapy regimens for unsuccessful H. pylori eradication
- Irradiation and systemic therapy for H. pylori-negative cases or patients who fail antibiotic therapy
Prognosis and Follow-up
MALT lymphoma generally has a favorable prognosis with a slow-growing nature, and many patients achieve long-term remission with appropriate treatment. Regular follow-up endoscopies are essential to monitor treatment response in gastric cases, as noted in the study published in the Annals of Oncology 1.
From the Research
Definition and Characteristics of MALT Lymphoma
- MALT (Mucosa-Associated Lymphoid Tissue) lymphoma is a type of non-Hodgkin's lymphoma that arises from the mucosal lymphoid tissue in various extranodal sites, such as the stomach, lung, eye, and salivary glands 2, 3.
- It is characterized by the presence of mature B-cells lacking expression of CD5 and CD10, and often presents with overlapping morphologic features but distinct clinical behaviors 2.
- MALT lymphomas are classified as extranodal marginal zone lymphomas of MALT-type, which represents about 8% of all non-Hodgkin's lymphomas 2.
Pathogenesis and Genetic Abnormalities
- The pathogenesis of MALT lymphoma is closely linked to chronic infections, such as Helicobacter pylori infection in the stomach, which can lead to the development of lymphoma 2, 4.
- Genetic abnormalities, such as t(11;18) and bcl10 nuclear expression, have been associated with MALT lymphoma and can influence the response to treatment 2, 5.
- The genetic constitution of MALT lymphoma is characterized by different, usually mutually exclusive, genetic abnormalities that lead to activation of the nuclear factor kappa B (NF-kappaB) pathway 4.
Diagnosis and Treatment
- Diagnosis of MALT lymphoma can be challenging, and endoscopic diagnosis is often difficult due to the lack of specific findings 6, 3.
- Narrow-band imaging (NBI) magnifying endoscopy can be useful in the diagnosis and evaluation of the response to eradication therapy of MALT lymphoma 6.
- Treatment of gastric MALT lymphoma often involves eradication of H. pylori infection, which can lead to remission in most patients 2, 4.
- Treatment of non-gastric MALT lymphomas is less well established, but may involve radiotherapy, systemic therapy, or antibiotic therapies 4.