[Thyroid lymphoma in a 51-year-old woman].

Thyroid gland is an uncommon site for involvement by lymphoma. Because of the lack of specific histopathologic criteria for diagnosis, thyroid lymphomas are not usually diagnosed until a thyroidectomy is done, even when a fine-needle aspiration biopsy is performed before surgery. We report the case of a woman with a non-Hodgkin lymphoma presenting as thyroid enlargement with systemic manifestations of the disease. The preoperative histologic diagnosis was poorly differentiated thyroid carcinoma. If the lymphoma was primarily thyroid or the involvement of thyroid was a part of the generalized dissemination of a nodal non-Hodgkin lymphoma is difficult to establish. She was treated with a combination of surgery and chemotherapy with excellent outcome. We comment the problems in the diagnosis of this disease.