Cystic metastases of the neck from occult thyroid adenocarcinoma.

In 9 of 118 patients with differentiated thyroid carcinomas, a solitary cystic lateral cervical mass simulating a branchial cleft anomaly was the sole presenting sign of the disease. These masses were nodal metastases of occult papillary adenocarcinoma of the thyroid that underwent liquefaction necrosis. Sonographically, the masses presented a complex pattern. Accordingly, it is suggested that, in patients presenting with an asymptomatic solitary lateral cystic cervical mass, the possibility of metastasis from an occult thyroid malignancy should be considered, and consent for definitive surgery should be obtained. The ultrasonic pattern of the cystic mass is of importance in the differentiation of a cavitated lymph node from a branchial cleft cyst.