Identification of continuity of transected nerve on sonography after neck dissection: direct sign of traumatic neuroma.

BACKGROUND

Traumatic neuroma can be confused with a metastatic lymph node after neck dissection for malignancy, thereby increasing patient anxiety and necessitating fine needle aspiration (FNA). To date, however, there have been no reports showing a direct ultrasonographic (US) sign of traumatic neuroma that could help distinguish it from a metastatic lymph node after neck dissection. Here, we describe a patient with traumatic neuroma who showed a direct US sign after total thyroidectomy with modified radical neck dissection (MRND).

SUMMARY: A 61-year-old man who had undergone total thyroidectomy with bilateral MRND for papillary thyroid carcinoma was found to have an oval-shaped nodule in his right lateral neck by US examination, which was first suspected of being a metastatic lymph node. However, when the position of the US transducer was changed to the oblique plane, a thin, cord-like, hypoechoic structure was found to be connected to the nodule. This structure passed between the longus capitis and scalenus medius muscles in an upward direction, and was ultimately located in the groove of the right transverse process of the C4 vertebra. Based on this anatomic relation, we concluded that the nodule was a traumatic neuroma and did not perform an unnecessary FNA.

CONCLUSIONS

The detection of a mass in the line of the transected nerve may be a direct US indication of traumatic neuroma after neck dissection.