Endocrine Abstracts

Introduction: Primary lymphoma of the thyroid (PTL) is a rare cause of malignancy, accounting for 5% of thyroid malignancies, with an annual estimated incidence of 2 per 1 million. Women are more commonly affected than men (2–8:1). Patients typically present in the sixth or seventh decade of life. Most thyroid lymphomas are non-Hodgkin’s lymphomas (NHLs) of B-cell origin. Patients with Hashimoto’s thyroiditis are at greater risk for developing PTL. Treatment and prognosis of PTL depend upon the histology and stage of the tumor at diagnosis.

Case report: We present a 50 years old man with a rapidly enlarging neck mass with compressive symptoms including dyspnea and stridor, requiring intubation. The cervical ultrasound revealed a sub-sternal goiter with heterogeneous, hypoechoic echostructure, and the fine-needle aspirating cytology was consistent with lymphocytic Hashimoto thyroiditis. The computed tomography (CT) scan revealed an enlarged thyroid gland with tracheal deviation as well as right neck lymphadenopathy. Thyroid function studies show thyroid-stimulating hormone 8.1 μIU/ml (reference, 0.27 to 4.20 μIU/ml), free thyroxine 13.7 ng/dl (reference, 12 to 22 pmol/dl), and positive anti-thyroperoxidase (TPO) antibodies. The core needle biopsy of the thyroid grand for combined pathology and immunohistochemistry revealed diffuse large B cell non-Hodgkin’s lymphoma with germinal center B-cell subtype.

Conclusions: Thyroid lymphoma is a rare cancer but must be considered in the differential diagnosis of patients presenting with an enlarging neck mass and a history of Hashimoto’s thyroiditis. Advances in both diagnosis and treatment in recent years have altered our approach to the management of this disease.