Diagnosis and outcome of childhood perineurioma

Indications and Outcomes of Nerve Reconstructions After Resection of Extremity Tumors: A Systematic Review

Objective: Peripheral nerve injuries resulting from tumor resection are unusual, but occasionally unavoidable. It can result in serious morbidity in motor deficits, sensory deficits, and even chronic pain. Nerve reconstruction after tumor resection is possible and seems to have positive recovery outcomes. However, nerve reconstructions are rarely performed and clear outcomes of nerve reconstructions after tumor resection are missing. This review aims to create an overview of the indications and outcomes in these patients. Methods: A systematic review was performed in May 2024 in PubMed and Embase databases according to the PRISMA guidelines. Search terms related to "tumor" and "nerve reconstruction" were used. Studies evaluating nerve reconstructions (nerve graft, transfer or coaptation) after tumor resection were included. Tumors not located in the extremities were excluded. A qualitative synthesis was performed on all studies. Where possible, motor, and sensory grades were recalculated according to the Medical Research Council (MRC)-scale. Results: Fifty-nine articles were included for quality synthesis after full-text screening. A total of 90 patients were described of which 44 after resection of malignant tumors. Most patients improved in motor and sensory function after nerve reconstruction. In both benign and malignant tumors, 77% demonstrated functional recovery on the MRC scale of ≥3. Most of the patients, >80%, recovered to a protective sensation of S2 or higher. Conclusion: Nerve reconstruction after tumor resection can help recover both sensory and motor function and may avoid chronic nerve pain. Nerve reconstructions should therefore be considered in tumor surgery.

Clinical Features, Natural History, and Outcomes of Intraneural Perineuriomas: A Systematic Review of the Literature

BACKGROUND

Intraneural perineurioma is a rare peripheral nerve sheath tumor characterized by localized proliferation of perineurial cells. The literature consists predominantly of case reports and institutional series, with inconsistent and confusing nomenclature. We present a pooled analysis of all reported cases of intraneural perineurioma in the literature.

METHODS

A systematic search of PubMed, MEDLINE, Embase, and Scopus was performed according to PRISMA guidelines to identify all reported cases of intraneural perineurioma in the literature. Individual cases were pooled and analyzed for demographics, clinical features, and outcomes.

RESULTS

A total of 172 cases were identified across 72 studies, of which 149 were found in major peripheral nerves and their branches. Median age of patients at diagnosis and onset of symptoms was 18 years (interquartile range [IQR], 12-34 years) years and 13.5 years (IQR, 8-26 years), respectively, with 54.4% (81/149) being female. The most common sites were the sciatic nerve or its branches (41.9%), median nerve (13.5%), radial nerve (12.2%), and brachial plexus (12.2%). Most patients were managed conservatively (52.9%; 72/136). Among those managed conservatively with available follow-up (n = 31), median follow-up was 11 months, and most (67.7%, n = 21) reported no change in neurologic status, although worsening was noted in 29.0% (9/31). Among surgically managed cases (n = 64), the most common intervention was resection with or without repair (62.5%; 40/64), neurolysis (25%; 16/64), or tendon transfers without resection (12.5%; 8/64). No lesion recurred after surgical resection.

CONCLUSIONS

Intraneural perineurioma represents a benign focal lesion presenting with weakness and atrophy affecting adolescents and young adults. Most cases are managed nonoperatively and surgical treatment strategies are varied.

Perineurioma: A Rare Entity of Peripheral Nerve Sheath Tumors

OBJECTIVE

 Intraneural perineurioma is a rare tumor entity. It is a benign, very slow growing peripheral nerve sheath tumor that typically occurs in children and young adults. Motor deficits and muscle atrophy are classic presenting symptoms, while sensory deficits are rare at the onset of the disease. Recommended treatment strategies are lacking. We have evaluated the clinical follow-up and our experience with treatment of this rare entity.

METHODS

 A total of 30 patients with intraneural perineuriomas were assessed retrospectively. Demographic data, clinical symptoms, diagnostic examinations, therapy strategies, and clinical outcome were analyzed. Descriptive statistical methods were used for evaluation.

RESULTS

 The mean age was 22 years. Eleven women and 19 men were affected. The lesion occurred in the area of the upper extremity in 16 patients and in the area of the lower extremity in 14 patients. The most frequently affected nerve was the sciatic nerve, followed by the radial nerve. All patients showed a motor deficit to some extent. Seventy percent (n = 21) revealed atrophy, 43.3% (n = 13) had sensitive deficits, and 17% (n = 5) suffered of pain. Fascicle biopsies were performed in 26 patients (87%). In four patients (13%), the tumor was completely resected and then reconstructed via nerve grafts. Seventy percent of the patients (n = 21) received a magnetic resonance imaging (MRI) within 5 years postoperatively, in which no progress was shown.

CONCLUSIONS

 To diagnose perineurioma, it is essential to take a biopsy of an enlarged, nonfunctional fascicle. Furthermore, a long-distance epineuriotomy to decompress the hypertrophic fascicle is reasonable. To preserve the nerves' residual function, a complete resection is not recommended. Results after grafting are poor. One reason for this might be residual tumor cells along the nerve that cannot be visualized. Malignant transformation is not yet reported and tumor growth is stable for years.

Intrinsic peripheral nerve and root tumor and pseudotumoral lesions at a tertiary care pediatric hospital

PURPOSE

Tumors affecting peripheral nerves in children are rare. Accurate diagnosis ensures that management is appropriate and timely. A review of intrinsic nerve tumors was completed to differentiate common peripheral nerve lesions based on clinical characteristics and investigations.

METHODS

A retrospective review was conducted for children (< 18 years old) diagnosed with an intrinsic tumor affecting peripheral nerve(s) or roots at the Children's Hospital of Eastern Ontario (CHEO) from 2009 to 2019.

RESULTS

We report 14 children with perineurioma (N = 6), neurofibroma (N = 4), intraneural ganglion cyst (N = 2), or lipomatosis (N = 2). Mean age of symptom onset was 8.2 years (range 0.3 to 17.3 years). Presenting symptoms included muscle weakness (7/14), painless muscle wasting (2/14), contracture (1/14), pain (1/14), or the identification of a painless mass (3/14). Nerve conduction studies (NCS) or electromyography (EMG) were performed in 11/14 patients. MRI was useful at differentiating between these pediatric nerve tumors. Biopsies were performed in nine patients with additional surgical management pursued in four patients.

CONCLUSION

The rare nature of peripheral nerve tumors in children can pose diagnostic challenges. NCS/EMG are important to assist with localization, and MRI is useful to distinguish more benign tumors. Key MRI, clinical, and NCS features can in some cases guide management, potentially avoiding the need for invasive procedures.

Clinical and Radiological Follow-up of Intraneural Perineuriomas

BACKGROUND

Management of intraneural perineuriomas remains controversial, largely due to the lack of knowledge regarding the natural history of these lesions.

OBJECTIVE

To describe the typical radiological growth pattern of intraneural perineuriomas and to determine how the pattern of growth relates to clinical progression.

METHODS

We performed a retrospective review of the magnetic resonance imaging (MRI) studies and serial clinical examinations of a cohort of patients with biopsy-proven intraneural perineuriomas who had 2 MRI studies at least 2 yr apart. The outcome of interest was radiological growth in length or width of the intraneural perineurioma. Radiological growth was tested for association with clinical progression.

RESULTS

Twenty patients were included in the study. By width, the lesions were on average larger on repeat imaging (P = .009). By absolute length, the lesions were on average longer on repeat imaging (P = .02). By lesion:landmark ratio, there was no difference in length of the lesions between sequential images (P = .09), with 10 (50%) lesions being shorter and 7 (35%) showing no change. No lesions grew to involve a new nerve or division of a nerve on sequential imaging. None of the variables tested were associated with clinical progression.

CONCLUSION

We found that intraneural perineuriomas only rarely grow in length, do not grow to involve new nerves or nerve divisions, and growth does not correlate with clinical progression. These findings have significant ramifications for management of these tumors.

Modern treatment of perineuriomas: a case-series and systematic review

Background

Perineuriomas are rare benign peripheral nerve sheath tumours of perineurial cell origin and can be classified into intraneural and extraneural perineuriomas. They most commonly present a mononeuropathy of gradual onset and slow progression, resulting in progressive neurological deficits like hypoesthesia or motor weakness. Therapy is still variable. Aim of the study was to compare our surgical treatment and our follow-up regime including high-resolution nerve sonography with the current literature to evaluate best treatment of perineuriomas.

Methods

Retrospective analysis of our dataset “peripheral nerve lesion” to identify patients suffering from perineuriomas between 01.01.2012 until 31.12.2018. Surgical treatment and the follow-up examination of three patients were described. Additionally, a systematic review including PubMed, the Cochrane Collaboration Library, Scopus and Google Scholar was performed for literature published between January 1, 1990 and October 31, 2019 independently by 2 authors.

Results

In the first case, the left ulnar nerve was affected. In the second case, the left peroneal nerve and in the third case the right median nerve was affected. High-resolution nerve sonography was performed in each case. All patients underwent interfascicular neurolysis combined with a targeted fascicular biopsy under electrophysiological monitoring. Neurological deficits improved subsidized by rehabilitation. Surgical therapy and the neurological outcome were compared with literature. Systematic review revealed 22 articles, which met the inclusion criteria. Therefore, demographics, surgical treatment and neurological outcome of 77 patients were analysed.

Conclusions

Perineuriomas are rare benign nerve sheath tumours with a slow progression, sometimes difficult to diagnose. Decompression and neurolysis may improve neurological deficits. High resolution nerve sonography might serve as a helpful additional diagnostic tool in this process.

Sodium Fluorescein as Intraoperative Visualization Tool During Peripheral Nerve Biopsies

OBJECTIVE

Owing to technical development of specific fluorophore filters, the neurosurgical application of sodium fluorescein (SF) has regained value in brain tumor surgery. The aim of this study was to determine the usefulness of SF during nerve biopsies.

METHODS

This single-center study included 5 cases of nerve biopsies performed under microscope-based fluorescence with SF performed between March 2016 and February 2017. SF was applied intravenously (1 mg/kg body weight). After microsurgical dissection of the involved nerve segment, fluorescence-guided fascicular biopsy was performed. Selection of target fascicles was at the surgeon's discretion and took into account nerve stimulation for preservation of motor function and fluorescence intensity. Correlation to histopathologic examination was examined. Video analysis of intraoperative images comparing target fascicles with intense fluorescent response to adjacent fascicles of the same nerve segment was performed using ImageJ.

RESULTS

All patients had motor or sensory deficits. Magnetic resonance imaging findings were similar, depicting long segments of gadolinium enhancement (minimum 11.7 cm). Each biopsy sample was positive resulting in diverse histopathologic results. Digital image analysis revealed a statistically significant difference of the complementary color green (P = 0.0473).

CONCLUSIONS

Magnetic resonance imaging is the gold standard in diagnostic work-up of peripheral nerve disorders. Longitudinal nerve thickening with positive contrast enhancement is an unspecific magnetic resonance imaging finding. Various pathologies, such as tumors and inflammatory lesions, may cause this morphologic phenomenon. Nerve biopsies may be needed for diagnostic work-up. Intraoperative SF may help to depict the most affected fascicles and identify target fascicles for biopsy and increase diagnostic certainty of nerve biopsies.

Clinicoradiological features of intraneural perineuriomas obviate the need for tissue diagnosis

OBJECTIVE

This study aimed to define a set of clinicoradiological parameters with a high specificity for the diagnosis of intraneural perineurioma, obviating the need for operative tissue diagnosis.

METHODS

The authors retrospectively reviewed MR images obtained in a large cohort of patients who underwent targeted fascicular biopsy and included only those patients for whom the biopsy yielded a diagnosis. Clinical and radiological findings were then tested for their ability to predict a tissue diagnosis of intraneural perineurioma. The authors propose a new set of diagnostic criteria, referred to as the Perineurioma Diagnostic Criteria. The sensitivity, specificity, positive predictive value, and negative predictive value of several clinicoradiological methods of diagnosis were compared.

RESULTS

A total of 195 patients who underwent targeted fascicular biopsy were included in the cohort, of whom 51 had a tissue diagnosis of intraneural perineurioma. When the clinicoradiological methods used in this study were compared, the highest sensitivity (0.86), negative predictive value (0.95), and F1 score (0.88) were observed for the decision trees generated in C5.0 and rPart, whereas the highest specificity (1.0) and positive predictive value (1.0) were observed for the Perineurioma Diagnostic Criteria.

CONCLUSIONS

This study identified clinical and radiological features that are associated with a diagnosis of perineurioma. The Perineurioma Diagnostic Criteria were determined to be the following: 1) no cancer history, 2) unifocal disease, 3) moderate to severe hyperintensity on T2-weighted MR images, 4) moderate to severe contrast enhancement, 5) homogeneous contrast enhancement, 6) fusiform shape, 7) enlargement of the involved nerves, and 8) age ≤ 40 years. Use of the Perineurioma Diagnostic Criteria obviates the need for tissue diagnosis when all of the criteria are satisfied.