Branchial Cleft Cyst Mimicking Malignant Thyroid Neoplasm Concurrent with Medullary and Papillary Thyroid Carcinoma: a Case Report

ABSTRACT

Branchial cleft cysts are the most common lateral neck mass, and usually have well-delineated cystic structures under ultrasonography. Ultrasonography and fine needle aspiration cytology is very helpful during preoperative diagnosis. However, these cysts may occur in unusual locations and have a sonographic morphology similar to malignant thyroid neoplasm. A 61-year-old woman presented with thyroid nodules, and ultrasonography revealed a 0.8-cm, hypoechoic, solid nodule with microcalcifications in the right lobe of thyroid in the lower portion.Postoperative histopathological examination revealed the 0.8-cm hypoechoic nodule to be a branchial cleft cyst. In addition, concurrent medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC) were found. Herein, we present a rare case of branchial cleft cyst mimicking malignant thyroid neoplasm concurrent with medullary and PTC.