Primary Thyroid Lymphoma Associated With Graves' Disease

Abstract and Introduction

We report herein a case of thyroid mucosa-associated lymphoid tissue (MALT) lymphoma in a patient receiving antithyroid drug therapy for Graves' disease. A 75-year-old woman first presented with finger tremor and was diagnosed with Graves' disease on the basis of clinical and laboratory findings. Three years later, she presented with rapid and painless enlargement of the thyroid. Ultrasonography revealed a circumscribed hypoechoic area bilaterally in each lobe of the thyroid, and fine-needle aspiration biopsy showed diffuse monotonous infiltration of small- to medium-sized atypical lymphoid cells. ⁶⁷Ga scintigraphy was positive exclusively in the thyroid. After total thyroidectomy, the patient received radiation therapy for treatment of stage IE primary thyroid lymphoma. Results of histological examination, immunohistochemical analysis, and flow cytometric analysis confirmed MALT lymphoma. To our knowledge, there have been few published reports of primary thyroid lymphoma associated with Graves' disease. Our experience with this case, though rare, indicates that an enlarged thyroid in cases of Graves' disease should be examined carefully for primary thyroid lymphoma.

Primary thyroid lymphoma is a rare disease, representing approximately 5% of all thyroid malignancies. It is almost always a B-cell, non-Hodgkin's lymphoma,^[1] typically occurring in elderly women with Hashimoto's thyroiditis.^[2] Diffuse large B-cell lymphoma (DLBCL) and extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) are common subtypes of this malignancy.^[3,4] Because the normal thyroid gland lacks lymphocytic tissue, primary thyroid lymphoma is thought to develop from lymphocytic tissue acquired during the course of chronic inflammation or an autoimmune process.^[5] Graves' disease shares many clinical characteristics with Hashimoto's thyroiditis. For example, lymphocyte infiltrations in the thyroid gland, with or without a germinal center, are present in both diseases. However, primary thyroid lymphoma rarely occurs in patients with Graves' disease.^[6–10] We present a rare case of primary thyroid lymphomain a patient undergoing antithyroid drug treatment for Graves' disease.

Thyroid. 2004;14(9) © 2004 Mary Ann Liebert, Inc.

Cite this: Primary Thyroid Lymphoma Associated With Graves' Disease - Medscape - Sep 01, 2004.