Also called traumatic neuroma
Disorganised nonneoplastic proliferation of proximal end of severed/partially transected/injured nerve due to trauma or surgery
Usually painless, may be painful (especially on tapping/ palpation = Tinel sign))and may not respond to conservative therapy. Small, firm tender masses on palpation
Seen commonly in lower limbs, but also seen in oral cavity related to tooth extraction. Also seen in radial nerve and brachial plexus
Classification:
1. Spindle neuromas: Internal, focal, fusiform swellings, due to chronic friction or irritation to a nondisrupted, injured but intact nerve trunk
2. Terminal (lateral) neuromas: due to severe trauma with partial avulsion, disruption, or total transection of a nerve. Has a bulblous end. Usually after 1-12 months after amputation/trauma
Ultrasound:
Well defined, hypoechoic or similar to muscle
MRI:
Int on T1, int-to-high on T2 with ring like pattern (fascicular sign)
Treatment:
May be treated surgically or under ultrasound
Steroid is anti-inflammatory
Phenol produces severe demyelination and axonal degeneration
Glycerol works similarly, but is less effective
References:
1. Gruber H et al. Sonographically Guided Phenol Injection in Painful Stump Neuroma . AJR 2004; 182:952-954
2. Stuart RM et al. Sonography of Peripheral Nerve Pathology . AJR 2004; 182:123-129
