Perineurioma: A Rare Entity of Peripheral Nerve Sheath Tumors

Abstract

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.

Nerve conduction assessment and magnetic resonance imaging for the diagnosis of localized hypertrophic neuropathy of the sciatic nerve and the lumbo-sacral plexus

“…IP is a proliferation of perineural cells forming a "pseudo-onion" in the peripheral nerves affected [4,9]. The nerves most frequently affected by IP are the sciatic nerve, followed by the radial nerve [10]. Since pure perineuriomas are rare and most lesions classified as IP are instead LHN, the term "perineurioma" was proposed as a comprehensive category for a range of nerve conditions including neurofibroma, LHN and IP [11].…”

Magnetic Resonance Imaging of Nerve Tumors

“…12 Identifying avidly enhancing enlarged fascicles on postcontrast images may be helpful to distinguish perineuriomas from hypertrophic neurologic diseases, such as hereditary or inflammatory neuropathies, as the most important differential diagnosis. 32 The affected nerve also demonstrates increased ADC and low fractional anisotropy values. The ADC value of the lesion can approach 1.0 to 1.10 −3 mm 2 /s, possibly reflecting a more organized lesion in a young compact nerve.…”

“…They typically develop in young adults and children, and most commonly involve the sciatic, radial, and ulnar nerves, and also the sacral plexus. 13 14 25 32…”

“…They typically develop in young adults and children, and most commonly involve the sciatic, radial, and ulnar nerves, and also the sacral plexus. 13,14,25,32 On MRI, the affected nerve demonstrates low to intermediate signal intensity on T1W and heterogeneous high signal intensity on T2W with avid enhancement on postcontrast images. There is also a gradual increase of the nerve caliber proximally, followed by a gradual tapering distally (►Fig.…”

Health-related quality of life in patients with peripheral nerve tumors: results from the German multicentric Peripheral Nerve Tumor Registry

“…To date, clinical trial evidence with robust epidemiological and clinical information is limited mainly to single-center results regarding schwannoma and neurofibroma, most frequent among PNTs and benign tumors ( 4 ). Other rare entities, such as perineurioma, amyloidoma, lipoma, desmoid, lymphoma, and malignant peripheral nerve sheath tumors (MPNSTs), are scarcely described ( 5 , 6 ). No studies on life quality in patients with PNT have been conducted to date.…”