Thyroid lymphoma: a rare tumor requiring combined management.

Thyroid lymphoma is a rare disease which occurs mainly in elderly females. Most patients with thyroid lymphoma have Chronic Lymphocytic Thyroiditis (CLT), suggesting a role of chronic antigen stimulation in the development of the disease. We present two cases of thyroid Diffuse Large B-cell Lymphoma (DLBCL) diagnosed after surgery (subtotal thyroidectomy) by means of combined histology and immunohistochemistry (positive staining for CD-20) in two elderly female patients presenting at our institution for compressive symptoms (dysphonia in patient 1, dysphagia in patient 2) due to a gross neck mass. Fine-needle aspiration was compatible with lymphocytic thyroiditis in the first patient and was indeterminate in the second patient. The first patient had a long-lasting history of hypothyroidism due to CLT and was on L-thyroxine replacement therapy, whereas the second patient had normal thyroid function and negative thyroid autoantibodies. After surgery both patients underwent chemotherapy (cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) plus rituximab). At one-year follow-up both patients were disease-free. Thyroid lymphoma is an uncommon tumor which requires prompt diagnosis and combined management for a high rate of cure to be achieved.