Computed Tomography - Guided Aspirations of Parapharyngeal and Skull Base Masses

Abstract

Computed tomography (CT) - guided aspirations of 22 parapharyngeal and skull base masses were performed via an oblique approach between the ascending ramus of the mandible and the pterygoid plates. A 22 g spinal needle was inserted through an 18 g introducer needle for sampling. Diagnostic specimens were obtained in 20 cases including six salivary gland neoplasms, five squamous cell carcinomas, five infections, and two cysts. On average, 2.8 passes into the mass were required although fewer were necessary to diagnose neoplasms (2.0 passes). No complications occurred. In this series, 100% of neoplasms were detected cytologically and there were no false-negative results. In two cases (9.1%) there was a discrepancy between the initial aspiration report and the final histologic diagnosis. CT-guided aspirations of skull base masses are a viable alternative to what would otherwise be a difficult surgical approach for biopsy. Diagnostic samples are obtained in 90.9% (20 of 22) with an accuracy of 90% (18 of 20).