Lateral neck cyst as initial presentation of thyroid malignancy

A mass in the lateral aspect of the neck may cause a diagnostic dilemma for the clinician. Cystic lateral neck masses in young adults are most often benign as the most frequent cause is a branchial cleft cyst. However, this may be a pitfall as such a cystic mass can be a first presentation of occult malignancy.

Here we present a case of a 25-year-old female patient with a cystic mass in the right lateral neck. This lesion was eventually diagnosed as cystic degeneration within a metastatic invaded lymph node from papillary thyroid carcinoma. Total thyroidectomy with right central and lateral lymphadenectomy was performed.

The correct diagnosis risked to be missed as the initial appearance was mimicking a benign branchial cleft cyst.

We aimed to highlight the possibility of an underlying unsuspected thyroid carcinoma in young patients initially presenting with a neck mass mimicking the more common benign branchial cleft cyst. We underline the necessity of thoroughly examining suspected cysts as adequate diagnosis should avoid delayed treatment as it directly affects the tumor stage and prognosis.