Intraneural perineurioma – a retrospective study of 19 patients

Abstract

Introduction

Intraneural perineurioma is a benign neoplasm of peripheral nerve sheath with perineurial cell origin that typically affects teenagers and young adults and tends to result in a motor-predominant neuropathy. It is very rare lesion due to lack of familiarity among clinicians, lack of precise pathological diagnosis and uncertainties regarding its cause. The aim of our study is to present the epidemiology, clinical presentation, way of diagnosis and our management plan.

Study materials

Clinical monocentric study. Patients diagnosed as intraneural perineurioma tumor and managed by the same team of surgeons between 2009–2014.

Methodology

Nineteen patients were retrospectively chart reviewed. We included all patients with diagnoses of Intraneural perineurioma by MRI and or biopsy with morphological, immunohistochemical staining study confirmation. We classified patients by gender, age, symptoms, tumor localization, radiological aspect, management and pathological confirmation.

Results

Sex ratio was 10 males to 9 females with mean age of 31.2 (15–64). Weakness was presented in all cases with sensory component in 10 patients (52.6%). The ratio of upper limb to lower limb was 9–10 with 4 brachial plexus. All patients underwent MRI with 16 patients had nerves enlargement and 5 presented with typical fusiform tumor, hypointense to isointense on T1-weighted images and hyperintense on T2-weighted images. Eighteen patients were operated for excision biopsy and or palliative treatment for their motor deficit. Seventeen patients had pathological confirmation with a morphological pseudo-onion bulb shape and or specific immunohistochemical assay of (+) EMA and (−) s 100. One patient had only palliative treatment without excision biopsy.

Discussion

Our data confirms the equal penetration to both sex and upper to lower limbs. It confirms motor involvement of the tumor however, it shows high sensory component that can be accompanied in this type of tumors. MRI can show typical aspect but most of the time, it is nonspecific enlargement. A unique surgical strategy for each nerve lesion involvement was proposed and because of the benignity of the tumor, the surgical treatment focused to optimize the functional outcome. This study represents one of the most important and large clinical series of intraneural perineurioma in the literature.

Conclusion

Prospective studies with long-term follow-up are needed for this under diagnosed tumor. Its genetic and biochemical mechanism is still unknown.