Differentiation of branchial cleft cysts and malignant cystic adenopathy of pharyngeal origin.

Objective: There is an increasing incidence of head and neck cancers that present as neck masses in a nonsmoking nondrinking population. These masses can be confused with benign cystic neck masses. The purpose of this study was to determine imaging criteria to differentiate benign lateral neck cysts from malignant cystic adenopathy.

Materials And Methods: A retrospective analysis of patients who underwent contrast-enhanced neck CT between July 2003 and July 2011 was performed. Patients were diagnosed with either a branchial cleft cyst or pharyngeal squamous cell cancer. Each examination was reviewed by a neuroradiologist, and, for each cyst or cystic lymph node, the anatomic level in the neck, dimensions, wall thickness, septations, homogeneity, extracapsular spread, calcifications, and fat stranding were recorded. Data analysis was performed using Student t tests and chi-square tests.

Results: Twenty-one patients with branchial cleft cysts and 29 patients with squamous cell carcinoma met the inclusion criteria. Significant differences between the groups were found with regard to size, homogeneity, and extracapsular spread. Branchial cleft cysts were found to be larger on the long axis (p < 0.001), short axis (p < 0.001), and height (p < 0.001). They were less likely to have extracapsular spread (p = 0.044) or septations (p = 0.059) and more likely to be homogeneous (p < 0.001).

Conclusion: Misdiagnosis of malignant cysts in the neck may lead to delay in diagnosis, a violated neck, tumor spillage, and spread. Differences in radiographic criteria can guide clinical decision making in the patient with a neck mass. However, fine-needle aspiration may be necessary to confirm the diagnosis.