Characteristic Ultrasound Feature of Traumatic Neuromas After Neck Dissection: Direct Continuity with the Cervical Plexus

Abstract

Traumatic neuroma may be easily confused with recurrent lymphadenopathy in the neck, causing patient anxiety, need for fine-needle aspiration (FNA), and even surgery. The purpose of this study was to evaluate the ultrasound (US) features that differentiate traumatic neuroma from recurrent lymphadenopathy after lateral neck dissection (LND), focusing on direct continuity with the involved nerve. This study compared US features of 56 traumatic neuromas in 36 consecutive patients, with 56 recurrent lymphadenopathies in 34 consecutive patients who had a previous history of total thyroidectomy and LND for thyroid cancer. Direct continuity of a nerve with a nodule and other US factors of a nodule (the short axis diameter, short-to-long axis ratio, location, shape, margin, echogenicity, vascular flow, hilar line, cystic portion, and echogenic dots) were evaluated in the two groups. Traumatic neuromas after LND had a prevalence of 17.8% (36/202) on US. Direct continuity with the involved nerve was visible in 98.2% (55/56) of the traumatic neuromas. The involved nerves in these traumatic neuromas were either terminal type (4/55, 7.3%) or spindle type (51/55, 92.7%). The short axis diameters, short-to-long axis ratio, location, shape, margin, and echogenicity were significantly different (p<0.001) in these two groups. None of the traumatic neuromas had a hilar line, vascular flow, or cystic portion. Direct continuity with the cervical plexus may be a characteristic US feature of traumatic neuroma after LND. This feature, along with ancillary findings, may prevent unnecessary surgery as well as painful FNA.