Classification of tumors by imaging diagnosis and preoperative fine-needle aspiration cytology in 120 patients with tumors in the parapharyngeal space

Background: Tumors in the parapharyngeal space are rare, and preoperative diagnosis is difficult because of anatomical and histological complexity. Methods: To evaluate the usefulness of preoperative diagnosis, we compared the classification of tumor localization in the prestyloid and retrostyloid compartments by imaging and preoperative cytological diagnosis by fine-needle aspiration cytology with the postoperative histopathological diagnosis in 120 patients with tumors in the parapharyngeal space. Results: Tumors were located in the prestyloid and retrostyloid compartments in 68 and 52 patients, respectively. The majority of histopathological diagnoses in the prestyloid and retrostyloid compartments were pleomorphic adenoma and schwannoma, respectively. All malignant tumors were in the prestyloid compartment. The preoperative cytological diagnostic rate for benign or malignant tumor was 95.2%, which was not inferior to that for other head and neck lesions. Conclusion: Our results suggested that the preoperative classification of tumor localization and cytological diagnosis improved the accuracy of presumptive diagnosis.