[How to identify cystic lateral neck mass from CUP-like lesions: a diagnostic challenge].

A cystic lateral neck mass in adults represents a major challenge, as it can be difficult to distinguish between benign and malignant lesions. The incidence of carcinoma in initially benign treated neck cysts is estimated to be as high as 24%. The objective of this study was to ascertain the malignancy rate of cystic cervical masses and to provide a differentiation of cervical metastases in comparison to benign cervical cysts, utilising current guidelines.Between 2013 and 2023, a total of 155 patients with a suspected diagnosis of lateral neck cyst were recruited at the Department of Otorhinolaryngology at our University Hospital. All patients underwent cyst removal, either alone or in conjunction with panendoscopy.A histologically confirmed ipsilateral lymph node metastasis was identified in 21.9% of patients. The mean age of patients with malignant neck masses was significantly higher than that of patients with benign neck masses (64.0±12.8 versus 41.0±15.8; p<0.001). The probability of malignancy was low in patients younger than 54 years (11%), but increased markedly to 80% in the age group of 60-69 years. The clinical sensitivity for initial suspicion of a benign neck cyst was 60.3%, while the specificity was 48.7%.An individualized approach is necessary for the early diagnosis and treatment of unilateral neck cysts, as this condition requires a multifaceted assessment based on the patient's medical history, clinical findings, imaging, and clinical expertise. We advise that patients over the age of 40 years undergo image morphological staging, a "no-touch" panendoscopy, and histological confirmation.