Computed Tomography - Directed Fine Needle Aspiration of Skull Base Parapharyngeal and Infratemporal Fossa Masses

Abstract

Suspicious findings in the parapharyngeal region on computed tomographic (CT) or magnetic resonance imaging studies can be a diagnostic problem. Blind biopsy through the mucosa can be inadequate, since the abnormality is not directly visible. With CT guidance, fine needle aspiration (FNA) of parapharyngeal masses can be performed with a needle confidently placed within the lesion. Vital structures such as the carotid artery are avoided. We present a series of 33 CT-guided FNA on 30 patients to evaluate the safety and the degree of accuracy of the procedure. Most of the patients had been treated previously for local malignancy. All patients had surgical pathologic study, autopsy, or clinical and imaging follow-up to confirm the FNA cytology results. Twenty of the 33 biopsies were positive for malignant cells, confirming recurrence of the primary head and neck malignancy. Of the 33 CT-directed FNA, 13 were negative for malignant cells. Three of these 13 were found to be false-negative FNA. None of the patients had complications from the procedure. CT directed FNA of masses at the skull base or in the parapharyngeal area can be performed safely. A high degree of accuracy is achieved, with 30 (90.9%) accurate in identifying the presence or absence of malignancy in our series.