Endocrine Abstracts

Introduction: Primary thyroid lymphoma is a rare malignancy. In many series, it is reported that it is seen at a rate of 0.6-5% among thyroid cancers and approximately 2% among extranodal lymphomas. It is often seen as a painless mass in the neck. Almost all of them have underlying Hashimoto’s thyroiditis. In many instances, thyroid lymphoma was recognized after thyroid surgery for suspected carcinoma. The most common thyroid lymphomas are B-cell and Hodgkin lymphomas. The distinction between primary and secondary lymphoma is important because of the variables in diagnosis, treatment, and prognosis. Surgery, chemotherapy, radiotherapy, or combinations can be used in the treatment.

Case: A 69-year-old male patient underwent total thyroidectomy and central neck dissection due to a 3.5x2.5 cm nodule in the right thyroid lobe. During the operation, it was observed that the mass lesion in the right lobe had progressed to the lateral carotid and invaded the right internal jugular vein. In addition, partial right internal jugular vein excision was performed. The pathology report was determined as large B-cell lymphoma and lymphocytic thyroiditis findings were observed in the surrounding thyroid tissue. Lymphoma involvement was present in most of the lymph nodes. There was vascular and muscle invasion. In patient blood tests free T3:1.7 pg/ml (N:2.04-4.4), free T4:1.15 pg/ml (N:0.93-1.7) TSH:3.72 mIU/ml (N:0 .27-4.2), and Thyroid autoantibodies negative detected. The patient received 4 cycles of R-CHOP (Adriamycin + Cyclophosphamide + Rituximab + Vincristine) chemotherapy protocol. The before and after treatment PET-CT was reported as: The focus showing pathological 18F-FDG uptake in favor of malignant involvement in the whole body cannot be identified.

Conclusions: Thyroid lymphoma, which is rarely seen in patients presenting with a thyroid mass, should also be considered. While Hashimoto’s thyroiditis is seen in most primary thyroid lymphomas, primary thyroid lymphoma develops in only 0.6% of Hashimoto’s thyroiditis cases.