Endocrine Abstracts

Introduction: The association of thyroid carcinoma with Graves’ disease (GD) is considered rare. Over 85% of thyroid cancer in patients with GD was papillary thyroid carcinoma, although other histologic types including follicular, medullary, and anaplastic carcinoma could be found in some studies. We report here a series of cases of thyroid cancer discovered in patients with GD, in order to evaluate the incidence of thyroid carcinoma in patients operated on for GD and to identify criteria which may predict malignancy.

Patients and Methods: This is a retrospective study of patients who underwent surgery for Graves’ disease between 2010 and 2021, and for whom the pathological study revealed a thyroid carcinoma.

Results: Among 51 patients operated on for Graves’ disease, thyroid cancer was discovered in nine patients (17.6%). These were 9 women with an average age of 42 years (27 to 72 years). The indication for initial surgery was failure of medical treatment for Grave’s disease in 6 cases (66.7%) and papillary carcinoma diagnosed by fine needle aspiration of a thyroid nodule classified EUTIRADS IV or V in 3 cases (33.3%). A total thyroidectomy with bilateral central neck dissection was performed in all patients; due to malignancy on frozen section examination. The final histological examination confirmed, in addition to characteristic Graves’ lesions, the presence of a thyroid cancer. This one was a papillary microcarcinomas in 8 cases (88.7%) and a papillary carcinoma in one case (11.3%). Cancer was multifocal in only one patient. Furthermore, it was associated with lymph node metastasis in 8 patients. The nine patients underwent radioactive iodine therapy, with an average of 2-3 sessions per patient (100 mCi/session), until achieving a white cartography. The follow-up was marked by absence of recurrence in all patients.

Discussion/Conclusion: It was accepted that hyperthyroidism inhibited the development of neoplastic cells within the thyroid parenchyma. This concept is no longer accepted, even though the link between hyperthyroidism and cancer is controversial. The prevalence of thyroid cancer in Graves’ disease varies in the series between 0.4% and 9.8%. Literature shows that the presence of thyroid nodule(s) in patients with GD (25-33% of cases) may be considered as an indication for surgery because it is a suggestive indication of cancer. The most adequate radical surgery in this situation is to perform a total thyroidectomy. It has the advantage of better adjusting postoperative substitutive opotherapy doses and allows for a therapeutic supplement based on radioactive iodine.