Thymic mucosa-associated lymphoid tissue lymphoma involving lymph nodes

Thymic mucosa-associated lymphoid tissue (MALT) lymphoma involving lymph nodes is quite rare with only 13 previous cases reported in the literature.

The 33-years-old female was referred to our department for the investigation of abnormalities on computed tomographic (CT) scans. CT scans showed a 9-cm×3-cm mass composed of a mixture of soft tissue and fat at the anterior mediastinum with lymphadenopathy in the neck, axillary and mediastinal regions. She was underwent complete surgical resection of the mass with regional lymph node dissection through a median sternotomy. Histological examination of the surgical specimens confirmed the diagnosis of MALT lymphoma arising in the thymus with nodal metastasis. She achieved complete remission after postoperative rituximab combined chemotherapy.

Thymic MALT lymphoma occurs most frequently in Asian female aged 40-60 years and commonly appears anterior mediastinal masses on CT scans. The excised tissue is necessary to confirm the accurate histological diagnosis. The disease usually remains localized for a long time, making local surgical resection highly effective. However, when the lymph nodes are involved, effective treatment approaches of the disease is still undefined.

We report a case of thymic MALT lymphoma involving lymph nodes, in which the patient was successfully treated with primary site resection with regional lymph node dissection followed by rituximab combined chemotherapy. Surgery provided not only a useful approach for collecting tissue for an accurate histological diagnosis, but also an effective local treatment, even in the case of advanced-stage thymic MALT lymphoma.