Case report of API2-MALT1 fusion-positive MALT lymphoma arising from bilateral submandibular glands with no evidence of autoimmune syndromes.

Mucosa-associated lymphoid tissue (MALT) lymphoma arising from the salivary glands is usually associated with chronic infection or autoimmune syndromes, such as primary Sjogren syndrome. The occurrence of t(11;18)/API2-MALT1 is rare in salivary MALT lymphoma. Here we describe a case of API2-MALT1 fusion-positive MALT lymphoma of the bilateral submandibular glands with no evidence of autoimmune syndromes. A 70-year-old man complained of a painless swelling in the bilateral submandibular gland. Serology examination results were negative for anti-SSA and anti-SSB. His right submandibular gland was dissected, and he was diagnosed with MALT lymphoma with the API2-MALT1 fusion gene. Positron emission tomography/computed tomography scanning indicated mild fluorine-18-fluorodeoxyglucose uptake in the left submandibular gland and liver. He was treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone. After 6 years, the patient is alive and disease free. In the present case, the patient with API2-MALT1 fusion-positive MALT lymphoma had a good outcome despite the advanced clinical stage.