MALT lymphoma of the floor of the mouth: a case report.

MALT (mucosa-associated lymphoid tissue) lymphomas are low-grade extranodal B-cell lymphomas that may involve various sites in the head and neck including the thyroid, salivary, and lacrimal glands. Development of MALT lymphoma in the head and neck is often associated with autoimmune diseases such as Sjögren syndrome or Hashimoto thyroiditis. Here we report a case of a MALT lymphoma of the floor of the mouth that likely arose in the sublingual gland. The patient was successfully treated with external-beam radiation therapy and remained disease-free at the 4-year follow-up.