Prediction of lymph node status in patients with surgically treated head and neck squamous cell carcinoma via neck lavage cytology: A pilot study

Background: Neck dissection is a standardized surgical procedure for patients with head and neck squamous cell carcinoma (HNSCC) and plays a critical role in the choice of adjuvant treatment based on histopathological findings. Saline irrigation is routinely performed at the end of surgery. However, this irrigant is not used for diagnostic purposes. Methods: Intraoperative irrigation of the neck dissection wound was performed in 56 patients with HNSCC (N = 93 neck dissections), and the cytological suspension obtained was processed via the liquid-based cytology (LBC) technique, Papanicolaou staining, and immunocytochemical staining. Microscopic preparations were screened for the presence of tumor cells and classified as positive, borderline, or negative. These results were correlated with the histopathological and clinical data. Results: Neck lavage LBC demonstrated high diagnostic value in detecting lymph node metastases (N+) with extracapsular spread (ECS), with a specificity, sensitivity, negative predictive value, and positive predictive value of 93.1%, 100%, 100%, and 80%, respectively. Tumor cells were detected in 4.8% of N- cases, 20% of N+ cases without ECS, and 100% of N+ cases with ECS. Receiver operating characteristic curve analysis showed an area under the curve of 0.8429 for the prediction of N+ (p < .0001) and 0.9658 for the prediction of N+ with ECS (p < .0001). Conclusions: Differential lavage cytology can provide valid and rapid information on the lymph node status in patients with HNSCC and showed an excellent correlation with histopathology. Thus, neck lavage LBC may facilitate faster and more reasonable planning of adjuvant treatment and help improve the therapeutic management of patients with HNSCC.