Mucosa-Associated Lymphoid Tissue (MALT) lymphoma (also called MALToma or extranodal marginal zone lymphoma) is a B-cell non-Hodgkin lymphoma (NHL) that typically affects elderly patients in the 7th and 8th decades. MALTomas can be categorized according to their location as either gastric or nongastric. Gastric MALTomas are frequently associated with Helicobacter pylori (H. pylori) infection, whereas nongastric MALTomas are rather associated with autoimmune conditions (e.g., Sjögren syndrome, Hashimoto's thyroiditis). MALTomas typically present with nonspecific symptoms (e.g., fatigue, weight loss) and an unremarkable physical exam. Diagnosis is based on histopathology and immunohistochemistry. In the case of gastric MALTomas, a biopsy should be performed by upper gastrointestinal (UGI) endoscopy. Imaging techniques such as computed tomography (CT) are used for staging purposes. Treatment depends on the type of MALToma: Gastric MALTomas, for example, are treated in most cases with the eradication of the underlying H. pylori infection, whereas nongastric MALTomas are treated with radiation, chemotherapy, and surgery.
- Approx. 5% of NHLs are due to MALTomas
- Peak incidence: 7th and 8th decades
Epidemiological data refers to the US, unless otherwise specified.
- Gastric MALTomas: multiple studies show an association with H. pylori infection.
- Nongastric MALTomas: frequent association with autoimmune conditions
- Salivary gland MALTomas → see
- Thyroid MALTomas → see
MALTomas show an association with chronic immune stimulation (bacterial, autoimmune)! References:
- Symptoms depend on the affected organ
- Gastric MALTomas
- Salivary MALToma: parotid enlargement
- Blood analysis: anemia
- Histopathology and immunohistochemistry
- Imaging: CT, MRI for tumor staging
- Additionally, upper gastrointestinal (UGI) endoscopy
- Should be performed even if patient tests negative
- Eradication of H. pylori is curative in up to 90% of low-malignant gastric MALTomas
- If H. pylori eradication therapy fails → radiotherapy or chemotherapy
- Surgery: gastric resection only necessary if complications (e.g., perforation, bleeding, obstruction) occur.
- Depends on the exact type and staging
- Treatment options include : radiation, chemotherapy, surgery for local diseases