The incidence of malignancy in clinically benign cystic lesions of the lateral neck: our experience and proposed diagnostic algorithm.

AIM: Solitary cystic masses of the lateral neck in an adult patient can pose a diagnostic dilemma. Malignancy must be ruled out since metastases arising from H&N cancers may mimic the presentation of benign cystic masses. Only a small number of studies have investigated the diagnostic management and malignancy rate of clinically benign solitary cervical cystic lesions. There are no established guidelines for the diagnostic evaluation.

METHODS

Retrospective review of the clinical, cytological, radiological, and pathological records of all adult patients (> 18 years) operated on for second branchial cleft cysts (BrCC) between 1/2008-2010/2016. Patients with apparent primary H&N malignancy, history of H&N cancer or irradiation, preoperative fine needle aspiration (FNA) of highly suggestive or confirmed malignancy, missing pertinent data, or age less than 18 years were excluded from analysis.

RESULTS

28 patients were diagnosed as having BrCC. The diagnosis was based on clinical findings, FNA cytology, and typical sonographic features. The histologic analysis determined an overall rate of malignancy of 10.7% (3/28): two patients had metastatic papillary thyroid carcinoma, and one patient had metastatic tonsillar squamous cell carcinoma. Purely cystic features on pre-operative ultrasound was the only significant predictor for true BrCC on final histology (p = .02).

CONCLUSIONS

Occult malignancy is not rare among adult patients presenting with a solitary cystic mass of the lateral neck. A diagnostic algorithm is proposed. Further studies are needed to establish the appropriate workup and management of an adult patient presenting with a solitary cystic mass of the lateral neck.