The prevalence of benign breast diseases in patients with nodular goiter and Hashimoto's thyroiditis.

Purpose: The evidence regarding association between thyroid disorders and benign and malignant breast diseases is increasing. The studies exploring the relationship between thyroid and breast diseases usually have focused on thyroid autoimmunity and functions in patients with breast pathologies. In this study, we aimed to reveal the frequency of benign breast conditions in patients with nodular thyroid disease (NTD) and Hashimoto's thyroiditis (HT).
Methods: Seventy-one women with NTD, ninety-five women with HT and seventy-two healthy people as a control group were included in the study. Serum thyroid-stimulating hormone, free triiodothyronine, free thyroxine, and thyroid peroxidase autoantibody levels were measured, and thyroid and breast ultrasonography were performed by a single operator in order to determine thyroid and breast pathology.
Results: Benign breast diseases were detected in 54.9% of patients with NTD, in 47.4% of those with HT, and 29.2% of control group in the study (p < 0.01 for nodular and Hashimoto groups versus control group). Simple cyst was found to be the most frequent pathology among benign breast diseases; fibrocystic changes, mixed lesions, benign solid mass, ductal ectasia, and complex cyst followed it. No significant relation was found regarding thyroid function and autoimmunity in patients diagnosed with benign breast disease (p > 0.05).
Conclusions: The results of our study support the association between benign breast diseases and thyroid diseases. An important implication of this finding may be demonstration of the necessity of scanning for potential breast pathology in women with nodular or autoimmune thyroid disease in clinical practice.