The true malignancy rate in 135 patients with preoperative diagnosis of a lateral neck cyst

OBJECTIVE: In this study, the true malignancy rate in 135 patients with a preoperative tentative diagnosis of a lateral neck cyst (LNC) was assessed. Furthermore, the sensitivity and specificity of fine needle aspiration of suspected LNC were evaluated and the diagnostic delay was analyzed. STUDY DESIGN: This study was retrospective in design and included all patients who had undergone surgery for a suspected LNC in four secondary hospitals in the eastern regions of Denmark during the period of 2009 to 2012. METHODS: One hundred thirty-five patients were identified and included by means of a search strategy for NOMECO surgical procedure codes KENB40A+B in the electronic surgical booking systems. Because the procedure codes also include median neck cysts and fistulas, the latter were excluded manually. RESULTS: Of the 135 patients preoperatively diagnosed with LNC, a malignant postoperative histopathological diagnosis was revealed in 19 patients (14.4%). Of these, three individuals were between 35 to 40 years of age. In 17 cases, preoperative fine-needle aspiration biopsy showed benign cytology, whereas histopathology postoperatively proved to be malignant. This renders a sensitivity of 88.8% and a specificity of 60.0% for fine needle aspiration biopsy with regard to LNC diagnostics. CONCLUSION: This study suggests that, for patients older than 35 years, a cystic lateral neck mass should be considered potentially malignant; by contrast, LNC is a diagnosis of exclusion. Any delay in treatment should be avoided until final histopathological diagnosis has been obtained. Arguably, all patients older than 35 years with a cystic lesion laterally on the neck should be included in the fast-track cancer referral program. LEVEL OF EVIDENCE: 2b.