An evidence-based approach to the treatment of thyroid lymphoma

Background: Primary thyroid lymphoma is a rare tumor that makes up 1-5% of thyroid malignancies and less than 2% of extranodal lymphomas. The treatment and prognosis of thyroid lymphomas can be divided into two distinct clinicopathologic entities: pure mucosa-associated lymphoid tissue (MALT) lymphomas and diffuse large B-cell or mixed subtypes. Methods: An evidence-based review was performed to determine the role of fine-needle aspiration (FNA) biopsy and adjuncts as the first diagnostic test for thyroid lymphoma, the role of open surgical biopsy, the role of palliative surgery as well as the best treatment (combined chemoradiation versus single modality surgery or radiation) for thyroid lymphoma. The ideal treatment of thyroid lymphoma was further assessed for both diffuse B-cell and MALT histologic subtypes. Results: Although an evidence-based review was challenging primarily due to a lack of high-level evidence, several recommendations are possible and presented regarding the optimal diagnostic methods and treatment of thyroid lymphoma. FNA and adjuncts are recommended as the first test to diagnose thyroid lymphoma, but open surgical biopsy may still be required in many cases. Combined chemoradiation therapy is recommended for all diffuse B-cell or mixed lymphomas. Single modality therapy with surgery or radiation alone may be considered for early-stage (IE) intrathyroidal MALT lymphomas. No recommendations could be made regarding the role of palliative surgery. Conclusion: Evidence-based recommendations can be applied to the individual patient with thyroid lymphoma with the involvement of an experienced multidisciplinary team consisting of an endocrine/oncology surgeon, radiation oncologist, and medical oncologist.