Incidence of unsuspected metastases in lateral cervical cysts.

OBJECTIVE: Solitary cystic squamous cell carcinoma metastases may be difficult to distinguish clinically from a benign cervical cyst. We sought to identify the incidence of solitary cystic squamous cell carcinoma metastasis in patients presenting with apparently benign cervical cysts.

STUDY DESIGN: Retrospective review.

METHODS: The records of all patients who presented with isolated lateral cervical cysts between 1983 and 1999 were reviewed. Patients with a clinically apparent primary malignancy, a history of head and neck cancer, a history of irradiation, or age less than 18 years were excluded from analysis, as were patients with a histological diagnosis of nonsquamous cell malignancy or those without a final histological diagnosis.

RESULTS: One hundred twenty-one adult patients presented with an initial diagnosis of lateral cervical cyst. Metastatic squamous cell carcinoma was demonstrated histologically after surgical excision in 12 patients (9.9%). The incidence of malignancy was significantly greater in patients greater than 40 years of age (23.5%, P < .0001). Results of preoperative fine-needle aspiration (FNA) were negative for malignancy in five cases of metastatic squamous cell carcinoma. Panendoscopy with directed biopsies revealed an occult primary in the base of tongue in three patients, tonsil in one patient, and nasopharynx in one. No primary was found in six patients, despite repeated examinations and close follow-up.

CONCLUSIONS: Solitary cervical cysts in patients older than 40 years of age should be presumed to be carcinoma until proven otherwise. A negative FNA result may be misleading, because of hypocellularity of the cyst fluid. Excisional biopsy should be undertaken with provisions made for frozen-section analysis of the specimen and contingency panendoscopy with directed biopsies of Waldeyer's ring if frozen-section histological examination reveals malignancy.