Radiologic Features of Papillary Carcinoma in the Second Branchial Cleft Cyst.

Clinically, it may be very difficult to differentiate between benign branchial cleft cyst (BCC) and malignant BCC with papillary carcinoma preoperatively. Radiological features were reviewed retrospectively between benign BCC and malignant BCC with papillary carcinoma using computed tomography (CT) and magnetic resonance (MR) images. All patients had only a mass on the right upper lateral neck without lesion in the thyroid gland. Two patients had a mass in the upper medial part of BCC on CT images and one patient showed a well-circumscribed mass in the upper portion of BCC on MR image. Two patients received BCC removal only and one patient underwent total thyroidectomy including removal of BCC. As results, most cases of papillary carcinoma in the BCC were detected incidentally after surgical resection of BCC. However, we can differentiate between benign BCC and malignant BCC with primary papillary carcinoma by carefully reviewing radiologic images before surgery.