Frequency of thyroid nodules and thyroid cancer in thyroidectomized patients with Graves' disease

Incidental thyroid cancers are frequently detected in patients operated on for Graves' disease (GD). There are no clear data about the incidence and risk factors of incidental thyroid cancer in operated GD patients. The aim of this study is to evaluate the risk of thyroid carcinoma in surgically treated GD patients.

The data of 121 GD patients who underwent total thyroidectomy in a single center between 2005 and 2015 were retrospectively evaluated. The diagnosis of thyroid cancer was based on pathological examination.

Thyroid cancer was demonstrated in postoperative pathology specimens of 34 patients who were surgically treated for GD (28.1%). Preoperative thyroid ultrasonography (USG) revealed a nodular goiter in 62 (51.2%) patients. Nodules were not detected in the other 59 (48.8%) patients with GD. The frequency of thyroid cancer was significantly higher in patients with nodules (38% vs. 16%; p = 0.009). Thirty-two of the 34 cancer cases had papillary thyroid cancer (PTC), and the remaining 2 had follicular thyroid cancer (FTC). Of the 32 PTC patients, 28 were classical type, 2 patients had the follicular variant, 1 was the oncocytic variant, and 1 was a tall cell variant.

The incidence of thyroid cancer was higher in patients who underwent surgery for GD. In addition to a careful physical examination in the follow-up of the patients with GD, ultrasonographic evaluation should be performed. Surgical treatment should not be delayed in patients with GD when indicated.