Ultrasound-guided percutaneous fine-needle aspiration in parapharyngeal space lesions: a critical appraisal with illustrative cases.

Abstract

Parapharyngeal space (PPS) lesions represent a rare and heterogeneous group of deep neck entities whose diagnostic evaluation is often challenging because of their deep anatomical location and their close relationship with major neurovascular structures. Cross-sectional imaging with computed tomography (CT) and magnetic resonance imaging (MRI) plays a central role in lesion characterization and anatomical localization. However, in selected cases cytological confirmation may be required to refine the differential diagnosis and guide clinical management. Ultrasound-guided percutaneous fine-needle aspiration (FNA) may represent a minimally invasive diagnostic option when an adequate acoustic window and a safe percutaneous access corridor can be identified. Nevertheless, PPS sampling differs substantially from routine cervical FNA because of the anatomical complexity of the region and the potential proximity to major vascular structures. This article provides a critical appraisal of ultrasound-guided percutaneous FNA for PPS lesions, focusing on anatomical considerations, technical workflow, and decision-making in patient selection. Three illustrative cases from our institutional experience demonstrate how imaging finding and ultrasound assessment guide the decision-making process in performing - or avoiding - percutaneous sampling of PPS lesions.