• Clinical science

MALT lymphoma (Extranodal marginal zone lymphoma)

Summary

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.

Epidemiology

  • Approx. 5% of NHLs are due to MALTomas
  • Peak incidence: 7th and 8th decades

References:[1]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

MALTomas show an association with chronic immune stimulation (bacterial, autoimmune)! References:[2][3][1]

Clinical features

  • Symptoms depend on the affected organ
  • Gastric MALTomas
  • Non-gastric MALTomas:
    • Salivary MALToma: parotid enlargement

References:[1][4]

Diagnostics

General approach

Gastric MALToma

References:[1][5]

Treatment

Gastric MALTomas

Nongastric MALToma

  • Depends on the exact type and staging
  • Treatment options include : radiation, chemotherapy, surgery for local diseases

References:[5][1]