Diagnostic accuracy and scope of intraoperative transoral ultrasound and transoral ultrasound-guided fine-needle aspiration of retropharyngeal masses

The use of transoral sonography-guided fine-needle aspiration for intraoperative localization of retropharyngeal masses has been described by Fornage et al. The purpose of this study was to assess the accuracy of this technique. We reviewed the images and medical records of 26 patients with a retropharyngeal lesion suspicious for a metastatic lymph node of Rouviere identified on CT and/or PET/CT. There were 14 patients with a history of thyroid cancer, 7 with mucosal squamous cell carcinoma, 1 with renal cell carcinoma, 1 with parotid acinic cell cancer, 1 with metastatic colon adenocarcinoma, and 2 with no history of cancer. Intraoperative transoral sonography was performed using a commercially available endovaginal transducer. A transoral sonography-guided fine-needle aspiration was performed with a 25-cm-long 20-ga Chiba needle through a needle guide attached to the transducer shaft. Cytopathologic results were categorized as malignant, benign, or nondiagnostic. Transoral sonography and transoral sonography-guided fine-needle aspiration were performed in all patients. A diagnostic specimen was obtained in 25 of 26 (96%) patients with a 100% overall accuracy. Twelve patients underwent subsequent transoral resection of the retropharyngeal mass. In each patient, surgical pathology confirmed the fine-needle aspiration biopsy result. In 4 patients, transoral sonography-guided injection of methylene blue was used to facilitate intraoperative localization of the metastatic retropharyngeal mass. Transoral sonography and transoral sonography-guided fine-needle aspiration of suspicious masses in the retropharyngeal space are highly accurate procedures for identification and cytologic evaluation of benign and metastatic lymph nodes of Rouviere and for presurgical localization.