MRI features of peripheral traumatic neuromas

• Published in: European radiology Vol. 26; no. 4; pp. 1204 - 1212
• Main Authors: Ahlawat, Shivani, Belzberg, Allan J., A. Montgomery, Elizabeth, Fayad, Laura M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2016; Springer Nature B.V
• Subjects: Adult; Bone surgery; Contrast Media; Diagnostic Radiology; Female; Humans; Image Enhancement; Imaging; Internal Medicine; Interventional Radiology; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medicine; Medicine & Public Health; Middle Aged; Musculoskeletal; Neuroma - pathology; Neuroradiology; Observer Variation; Orthopedics; Peripheral Nerve Injuries - pathology; Peripheral Nervous System Neoplasms - pathology; Radiology; Retrospective Studies; Tumors; Ultrasound; Young Adult; United States > US; Baltimore Maryland; Neuroma-in-continuity; End-bulb neuroma; Neuroma; MRI; Enhancement
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-015-3907-9

Objectives To describe the MRI appearance of traumatic neuromas on non-contrast and contrast-enhanced MRI sequences. Methods This IRB-approved, HIPAA-compliant study retrospectively reviewed 13 subjects with 20 neuromas. Two observers reviewed pre-operative MRIs for imaging features of neuroma (size, margin, capsule, signal intensity, heterogeneity, enhancement, neurogenic features and denervation) and the nerve segment distal to the traumatic neuroma. Descriptive statistics were reported. Pearson’s correlation was used to examine the relationship between size of neuroma and parent nerve. Results Of 20 neuromas, 13 were neuromas-in-continuity and seven were end-bulb neuromas. Neuromas had a mean size of 1.5 cm (range 0.6–4.8 cm), 100 % (20/20) had indistinct margins and 0 % (0/20) had a capsule. Eighty-eight percent (7/8) showed enhancement. All 100 % (20/20) had tail sign; 35 % (7/20) demonstrated discontinuity from the parent nerve. None showed a target sign. There was moderate positive correlation (r = 0.68, p = 0.001) with larger neuromas arising from larger parent nerves. MRI evaluation of the nerve segment distal to the neuroma showed increased size (mean size 0.5 cm ± 0.4 cm) compared to the parent nerve (mean size 0.3 cm ± 0.2 cm). Conclusion Since MRI features of neuromas include enhancement, intravenous contrast medium cannot be used to distinguish neuromas from peripheral nerve sheath tumours. The clinical history of trauma with the lack of a target sign are likely the most useful clues. Key Points • MRI features of neuromas include enhancement and lack of a target sign . • Contrast material cannot be used to distinguish traumatic neuromas from PNSTs . • Traumatic neuromas can simulate peripheral nerve neoplasms on imaging .