MALT Lymphoma : Sites

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MALT Lymphoma - Sites: MALT lymphomas usually occur in organs devoid of prominent organized lymphoid tissue. These sites acquire mucosa-associated lymphoid tissue (MALT) as a result of chronic inflammation of infectious, autoimmune, or unknown etiology.

The sites affected by MALT lymphomas include stomach (the most common site; accounts for 35% of all MALT lymphomas), ocular adnexa and orbit (13% of cases), skin (9%), lungs (9%), salivary glands (8%), breast (3%), thyroid (2%), liver, thymus, and others.

Some examples of chronic inflammatory or autoimmune conditions that predispose to MALT lymphomas include Helicobacter pylori gastritis, Hashimoto thyroiditis, and lymphoepithelial sialadenitis (usually associated with Sjogren syndrome). MALT lymphomas often regress if the inciting agent or the underlying source of inflammation is removed.

This gastric biopsy shows acquired MALT subsequent to Helicobacter pylori infection. Lymphoid tissue is not present in normal stomach. Image courtesy of: @PatholWalker.