A Case of Bilateral Lymphoepithelial Cyst in the Thyroid Gland

Abstract

A 52-year-old woman had been diagnosed with Hashimoto's thyroiditis and a thyroid cyst in her twenties. Her primary care physician referred her to our office with complaints of a rapidly enlarging thyroid lesion, dysphagia, and dyspnea. Cervical ultrasonography revealed a multilocular mass approximately 8 cm in diameter in the left lobe of the thyroid gland. This mass was composed of an anechoic cyst, and a cyst with an isoechoic solid lesion. Additionally, there were two unilocular cysts with an isoechoic solid lesion approximately 2 cm in diameter in the right lobe. Fine-needle aspiration of both lobes' lesions revealed no signs of malignancy. These lesions were slightly viscous and yellowish-white with turbidity. Total thyroidectomy was performed thereafter because of the rapidly enlarging thyroid lesion, and the possibility of a connection between the cystic lesion and the lymphatic vessels or thoracic duct. Histological findings revealed that the thyroid lymphoepithelial cysts contained cholesterol crystals. Based on the ultrasonographic and intracystic findings, we speculated that the diagnosis was not a challenging one.