Neuroma morphology: A macroscopic classification system

• Published in: Muscle & nerve Vol. 70; no. 6; pp. 1172 - 1180
• Main Authors: Raasveld, Floris V., Weigel, Daniel T., Liu, Wen‐Chih, Mayrhofer‐Schmid, Maximilian, Gomez‐Eslava, Barbara, Tereshenko, Vlad, Hwang, Charles D., Wainger, Brian J., Renthal, William, Fleming, Mark, Valerio, Ian L., Eberlin, Kyle R.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.12.2024; Wiley Subscription Services, Inc
• Subjects: Adult; Aged; Aged, 80 and over; amputation; biology; Classification; Comorbidity; Diabetes mellitus; extremity; Female; Humans; Male; Microenvironments; Middle Aged; Morphology; neuroma; Neuroma - classification; Neuroma - pathology; Pain; Pain Measurement; Patients; Peripheral Nervous System Neoplasms - classification; Peripheral Nervous System Neoplasms - diagnostic imaging; Peripheral Nervous System Neoplasms - pathology; Peripheral Nervous System Neoplasms - surgery; Prospective Studies; Reproducibility of Results; Vascular diseases; amputation; neuroma; biology; morphology; extremity
• ISSN: 0148-639X; 1097-4598; 1097-4598
• DOI: 10.1002/mus.28261

Introduction/Aims Neuromas come in different shapes and sizes; yet the correlation between neuroma morphology and symptomatology is unknown. Therefore, we aim to investigate macroscopic traits of excised human neuromas and assess the validity of a morphological classification system and its potential clinical implications. Methods End‐neuroma specimens were collected from prospectively enrolled patients undergoing symptomatic neuroma surgery. Protocolized images of the specimens were obtained intraoperatively. Pain data (Numeric rating scale, 0–10) were prospectively collected during preoperative interview, patient demographic and comorbidity factors were collected from chart review. A morphological classification is proposed, and the inter‐rater reliability (IRR) was assessed. Distribution of neuroma morphology with patient factors, was described. Results Forty‐five terminal neuroma specimens from 27 patients were included. Residual limb patients comprised 93% of the population, of which 2 were upper (8.0%) and 23 (92.0%) were lower extremity residual limb patients. The proposed morphological classification, consisting of three groups (bulbous, fusiform, atypical), demonstrated a strong IRR (Cohen's kappa = 0.8). Atypical neuromas demonstrated higher preoperative pain, compared with bulbous and fusiform. Atypical morphology was more prevalent in patients with diabetes and peripheral vascular disease. Discussion A validated morphological classification of neuroma is introduced. These findings may assist surgeons and researchers with better understanding of symptomatic neuroma development and their clinical implications. The potential relationship of neuroma morphology with the vascular and metabolic microenvironment requires further investigation. Peripheral nerve injury can lead to symptomatic neuroma formation, which may require surgical excision and targeted muscle reinnervation (TMR) or regenerative peripheral nerve interface (RPNI). The study examined 45 neuroma specimens from 27 patients, classifying them as bulbous, fusiform, or atypical. Pre‐operative pain was measured and compared across neuroma morphologies. The suggested classification system showed high inter‐rater reliability (κ = 0.8). Atypical neuromas were linked to higher pre‐operative pain levels and were more common in patients with diabetes or peripheral vascular disease. This morphological classification may help link neuroma types to specific symptoms, potentially improving treatment strategies for patients with painful neuromas.