Hyperthyroidism with thyroid cancer: more common than expected?

Hyperthyroidism is a group of diseases with many different etiologies and clinical manifestations. The most common causes include toxic multi-nodular goiter, Graves' disease and toxic adenoma. The prevalence of thyroid cancer developing in patients with hyperthyroidism has gradually increased in recent years. The aim of this study is to detect the incidental thyroid cancer rates in patients who have undergone a surgical operation due to hyperthyroidism, and to specify the patient groups in whom surgical treatment should come into the foreground.

A total of 591 patients, who had surgical excision of the thyroid due to hyperthyroidism between January 2007 and June 2017, were retrospectively analyzed.

Of all the patients included in the study, 377 (63.7%) had multi-nodular goiter, 132 (22.3%) had Graves' disease, 55 (9.4%) had nodular Graves' disease, and 27 (4.6%) had toxic adenoma. Thyroid cancer was determined in 131 out of 591 patients (22.6%) who were operated. The most common histologic type was thyroid micropapillary carcinoma (65/131; 49.6%). The accompanying pathologies to thyroid cancer were as follows: Toxic multi-nodular goiter (89/131; 67.9%), nodular Graves' disease (24/131; 18.3%), Graves' disease (13/131; 9.9%) and toxic adenoma (5/131; 2.8%).

Prevalence of cancer on a background of hyperthyroidism has gradually increased in recent years. It is not realistic to determine thyroid cancer prevalence only based on autopsy examinations. This rate significantly increases in the presence of nodule in clinical studies. Most of the carcinomas are microcarcinomas that do not have lymphovascular invasion and have very low lymph node metastasis. Thus, their treatment is still under debate.

Hyperthyroidism Micropapillary Cancer, Thyroid cancer.