Rare Pulmonary Metastasis From Thyroid Mucosa-Associated Lymphoid Tissue Lymphoma

Primary pulmonary lymphomas constitute up to 1% of all pulmonary malignancies. Patients with mucosa-associated lymphoid tissue (MALT) lymphoma represent approximately 90% of patients with primary pulmonary lymphoma. Most pulmonary MALT lymphomas are primary tumors. Pulmonary metastasis is extremely rare. A 65-year-old woman was diagnosed with a thyroid MALT lymphoma in 2008 and underwent total thyroidectomy, followed by chemotherapy. After 5 years of follow-up, she referred to our hospital with an abnormal shadow on a chest roentgenogram. She underwent video-assisted thoracoscopic surgery and was diagnosed with metastatic thyroid MALT lymphoma. Postoperatively, she was treated with chemotherapy, including rituximab, and is alive without recurrence.