The Role of Ultrasound in the Diagnosis of Intraneural Perineurioma

ABSTRACT Introduction/Aims Reports on imaging‐based diagnosis of intraneural perineurioma remain limited. This study aimed to summarize the role of ultrasound in diagnosing intraneural perineuriomas to enhance clinical awareness and diagnostic accuracy among clinicians and ultrasonographers. Methods A retrospective study was conducted on 11 patients diagnosed with intraneural perineurioma through surgery or biopsy at our hospital between June 2015 and June 2022. All patients underwent ultrasonography, and their ultrasonographic characteristics were analyzed. Results All patients presented with isolated mononeuropathy. Sonography revealed fusiform enlargement of the affected nerve. The length of the lesion ranged from 1.5 to 20.0 (5.2 ± 5.4) cm. The intraneural perineuriomas were hypoechoic relative to skeletal muscle. The internal homogeneity was heterogeneous, without posterior acoustic enhancement. The lesion was centrally located within the nerve. The inner epineurium was blurred with a continuous fascicular structure. Two patients had hyperechoic calcifications with posterior acoustic shadows in their lesions. Vascularization assessment using color or power Doppler imaging revealed blood flow in all the tumors. The cross‐sectional area of the affected nerves was at least twice as large as that of the contralateral side, with some patients exhibiting up to an eight‐fold increase. Discussion High‐frequency ultrasonography provides important evidence for the clinical diagnosis of intraneural perineurioma. When combined with magnetic resonance imaging and electrophysiological studies, ultrasound can aid in clinical decision‐making and facilitate long‐term monitoring. Given its accessibility and diagnostic potential, ultrasonography can be one of the preferred imaging examinations for evaluating intraneural perineuriomas.