Plexal intraneural perineurioma: an analysis of the clinicoradiologic presentation of this rare variant

• Published in: Acta neurochirurgica Vol. 165; no. 4; pp. 927 - 934
• Main Authors: Lenartowicz, Karina A., Amrami, Kimberly K., Spinner, Robert J.
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.04.2023; Springer Nature B.V
• Subjects: Adolescent; Adult; Atrophy; Brachial Plexus; Brain tumors; Children; Cranial Nerve Neoplasms; Diagnosis; Electronic medical records; Female; Humans; Infant; Interventional Radiology; Magnetic Resonance Imaging; Male; Medicine; Medicine & Public Health; Minimally Invasive Surgery; Nerve Sheath Neoplasms - diagnostic imaging; Nerve Sheath Neoplasms - surgery; Neurology; Neuroradiology; Neurosurgery; Original Article - Brain Tumors; Patients; Peripheral nerves; Peripheral nervous system; Peripheral Nervous System Neoplasms - diagnostic imaging; Peripheral Nervous System Neoplasms - surgery; Peripheral neuropathy; Polyneuropathy; Surgical Orthopedics; Surgical outcomes; Young Adult; Plexus; Intraneural perineurioma; Peripheral nerve sheath
• ISSN: 0942-0940; 0001-6268; 0942-0940
• DOI: 10.1007/s00701-022-05442-0

Purpose Intraneural (IN) perineurioma is a rare benign peripheral nerve sheath tumor, typically presenting as a painless, progressive mononeuropathy in adolescents. A rare plexal variant has been described, although there are little data describing its clinicoradiologic features. Herein, we present the largest case series of plexal IN perineuriomas reported in the literature. Methods Electronic medical records (EMR) from 1990 to 2022 from a single academic institution were reviewed for a diagnosis of IN perineurioma involving the brachial or lumbosacral plexus. This identified 18 patients, of which 17 had available MR imaging. We reviewed the EMR for demographics, clinical presentation, imaging characteristics, and surgical outcomes. Results Eighteen patients were identified. Most patients were male (11/18, 61%) and first developed symptoms at the age of 9.6 years (range 7 months to 55 years). Diagnosis occurred on average at the age of 22 years (4–57 years), which is significantly earlier than distal IN perineurioma ( p  = 0.0096). All patients (100%, 17/17) presented with motor polyneuropathy and muscular atrophy in multiple nerve distributions, with associated sensory loss (12/17, 71%). Most plexal lesions occurred in the brachial plexus (66%, 12/18). Five (29%, 5/17) patients presented with a hand/foot discrepancy, and 5 patients (29%) had a limb length discrepancy. Five patients underwent tendon transfer, of which two had failure of tendon transfer at most recent follow-up (50%, 2/4) due to progression of neurologic loss affecting the donors. Of patients managed nonoperatively, 87% of patients (6/7) with follow-up information demonstrated disease progression with worsening motor function or sensory loss, and 2 patients demonstrated progression on imaging at most recent follow-up. Conclusions Plexal perineurioma represents an uncommon variant of IN perineurioma that presents as a progressive motor and sensory polyneuropathy in childhood or early adolescence. Surgical management remains controversial, and tendon transfer tends to result in poor long-term surgical outcomes.