Endocrine Abstracts

Introduction: Oncocytic tumors can occur in the thyroid gland and other endocrine tissues, including the parathyroid, pituitary gland, adrenal cortex, pancreas, gut, and lung. Thyroid oncocytic tumors are rare: 3-10% of thyroid epithelial tumors. They are characterized by the presence of oncocytic cells called “Hürthle” cells.

Objective: Describe the clinical, pathological and therapeutic features of oncocytic tumors of the thyroid gland.

Methods: A retrospective study including 35 cases of thyroid oncocytic tumors treated in our department between 1988 and 2021.

Results: The average age of our patients was 48 years. The sex-ratio (F/M) was 10,9. The mean size of the nodules on ultrasonography was 31,3mm. The nodule was unique in 25 cases. The nodules were classified according to the EU-TIRADS classification: EUTIRADS 2 (12 cases), EUTIRADS 3 (22 cases), EUTIRADS 4 (10 cases) and EUTIRADS 5 (10 cases). A lobectomy was performed in 31 cases, a total thyroidectomy was done in 1 case, and an isthmectomy was done in 3 cases. Among our patients, 33 patients had oncocytic adenoma and 2 patients had oncocytic carcinoma. In case of oncocytic carcinoma, a totalization with central lymph node dissection and radioactive iodine therapy were done. Evolution was favorable in these 2 cases.

Conclusion: In general, oncocytic tumors do not have a specific clinical presentation or distinguished features on ultrasonography. Furthermore, distinguishing hyperplasia from neoplasia, and benign from malignant is difficult on cytology. Anatomopathological examination is often needed to make the diagnosis of these tumors. Compared to other differentiated tumors, oncocytic carcinomas tend to be more aggressive, and have less radioactive iodine intake. Overall survival in 5 years is 50-70%.