Extraneural Perineurioma Research Articles

Pseudolipoblastic Perineuroma: A Rare Histologi̇c Subtype.

Pseudolipoblastic perineurioma is a very uncommon variant of extraneural perineurioma, with only a limited number of cases documented in the medical literature. The most remarkable histopathologic characteristic is the existence of vacuolated cells that closely resemble lipoblasts; besides the presence of small, spindle shaped, or epithelioid perineurial cells. In this study, we present another case of pseudolipoblastic perineurioma, predominantly characterized by the presence of vacuolated "pseudolipoblastic" cells. The immunohistochemical expression of EMA, Glut-1, claudin-1, collagen type IV, and laminin as well as S-100 negativity is essential for the diagnosis to support the perineurial origin. Simple excision is the best treatment option for these benign tumors that do not recur or metastasize. It is crucial to recognize this rare entity to differentiate it from many other tumors characterized by prominent intracytoplasmic vacuoles.

EXTRANEURAL PERINEURIOMA OF THE MANDIBLE - A CASE REPORT

A 36-year-old female patient was referred to a private clinic presenting an asymptomatic, intraosseous lesion in the posterior right mandible. Itraoral examination revealed no significant alteration. X-rays and cone-beam computed tomography exams revealed a well-defined, radiolucent, hypodense lesion with a sclerotic border in the right side of the mandible. The tumor appeared to cause fusiform enlargement of the mandibular canal. After an incisional biopsy, histopathological analysis revealed a proliferation of slender, spindle-shaped cells with long cell processes arranged in storiform and short-fascicular patterns. The findings were suggestive of extraneural perineurioma. Immunohistochemical reactions for S100, EMA, and Glut-1 antigens confirmed the diagnosis. The tumor was resected under general anesthesia. Follow-up is still ongoing. Funding: CAPES/Brazil; FAPEMIG/Brazil; CNPq/Brazil. A 36-year-old female patient was referred to a private clinic presenting an asymptomatic, intraosseous lesion in the posterior right mandible. Itraoral examination revealed no significant alteration. X-rays and cone-beam computed tomography exams revealed a well-defined, radiolucent, hypodense lesion with a sclerotic border in the right side of the mandible. The tumor appeared to cause fusiform enlargement of the mandibular canal. After an incisional biopsy, histopathological analysis revealed a proliferation of slender, spindle-shaped cells with long cell processes arranged in storiform and short-fascicular patterns. The findings were suggestive of extraneural perineurioma. Immunohistochemical reactions for S100, EMA, and Glut-1 antigens confirmed the diagnosis. The tumor was resected under general anesthesia. Follow-up is still ongoing. Funding: CAPES/Brazil; FAPEMIG/Brazil; CNPq/Brazil.

Extraneural Soft Tissue Perineurioma: A Case Report

A perineurioma is a rare benign peripheral nerve sheath tumor derived from perineurial cells. Based on clinical and pathologic features, perineuriomas can be classified into two subtypes: Intraneural perineurioma and the extraneural perineurioma.

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

BackgroundPerineuriomas 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.MethodsRetrospective 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.ResultsIn 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.ConclusionsPerineuriomas 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.

Extraneural perineurioma: CT and MRI imaging characteristics.

To examine the CT and MRI characteristics of extraneural perineuriomas. With IRB approval, our institutional imaging database was retrospectively reviewed for cases of pathologically proven extraneural perineuriomas. CT and MRI features were recorded, correlative imaging analyzed, and the electronic medical record cross-referenced. We identified ten patients [(seven males, three females, mean age 49.4 ± 18.3years (range, 16-70years)]. All cases were pathologically confirmed. Nine cases were conventional soft tissue extraneural perineuriomas, including one with "reticular" features and one with histologic features of malignancy; the tenth case contained admixed Schwann cells (hybrid perineurioma/schwannoma). Six out of ten patients underwent CT and ten of ten MRI evaluation. Nine out of ten MRIs were performed with IV contrast. Five lesions were subcutaneous, four intermuscular, and one intramuscular. Mean lesion diameter was 4.3 ± 2.7cm (range, 0.9-10.2cm). Nine out of ten lesions were well circumscribed; one had irregular margins. On CT, five of six were hypodense and one isodense compared to skeletal muscle. Most lesions were T1 isointense (5/10) or hypointense (4/10) and T2 hyperintense (7/10) relative to skeletal muscle, and demonstrated solid enhancement (6/9). There was no evidence of muscular denervation on any MRI exam, and a nerve of origin was identified in two out of ten cases. Extraneural perineuriomas have a distinctly different imaging appearance from intraneural perineuriomas, manifesting as rounded or ovoid soft tissue masses, without evidence of muscular denervation, and usually without an apparent nerve of origin. Because these features mimic other benign and malignant soft tissue lesions, including sarcomas, biopsy or excision is needed for definitive diagnosis.

Intraosseous intraneural perineurioma derived from the inferior alveolar nerve with an abnormality of chromosome 22 and expression of the BCR-ABL fusion gene: report of a case and review of recent literature

BackgroundPerineurioma (PN) is a peripheral nerve disease that primarily develops in the limbs and trunk and very rarely occurs in the oral cavity. PN is classified into two types: intraneural perineurioma (INPN) and soft tissue perineurioma (extraneural perineurioma, ENPN). In this article, we report a patient with mandibular body INPN derived from the perineurium of the inferior alveolar nerve.Case presentationThe patient was a 43-year-old male. He consulted our department for a detailed examination of the right mandibular body. A biopsy was performed at another hospital and he was diagnosed with a schwannoma. At his first visit, hypesthesia extending from the right lower lip to the mental region was recognized and enlargement of the right mandibular canal was confirmed with X-ray CT and MRI. Considering the possibility of future tumor growth, we extirpated the tumor under general anesthesia. Cystic tumor was seen continuously in the inferior alveolar nerve. Immunohistologically, the tumor cells were positive for Glut-1, weakly positive for EMA, and weakly positive for Claudin-1, and the histopathological diagnosis was INPN. In addition, absence of the BCR region of chromosome 22 and expression of the BCR-ABL fusion gene were observed by fluorescent in situ hybridization (FISH), and a chromosome 22 abnormality was confirmed. These findings indicated that the disease was a neoplastic lesion.ConclusionExpression of the BCR-ABL fusion gene in INPN that develops in the oral cavity is thought to be very rare, and to the best of our knowledge, ours is the first case to be reported in the literature. About three postoperative years have passed, but findings suggestive of recurrence have not been observed.

Extraneural soft tissue perineurioma

Perineuriomas(tumors of perineurial cells) are relatively rare, benign peripheral nerve sheath-originated neoplasms, presentingextraneural or intraneural tumors. Extraneural perineuriomas seem to be more common than intraneural perineuriomas.Extraneural perineuriomas are found mainly in skin and soft tissues. Soft tissue perineurioma is a kind of extraneuralperineuriomas, and it is the most common type of perineuriomas. Histopathologically, soft tissue perineurioma is characterized bywell-circumscription, fibromyxoid stroma, and bland spindle cells representing the fascicles or whirling growth pattern, which isaccentuated on the perivascular zones. Herein, we present one case of extraneural soft tissue perineurioma occurring on thelower back region.

Cutaneous Intraneural Perineurioma

Perineuriomas are benign neoplasms composed of perineurial cells. Classically, perineuriomas are divided into 2 distinct clinicopathologic entities, known as intraneural and extraneural perineuriomas. Intraneural perineuriomas, first described as interstitial hypertrophic neuritis, involve the major nerve trunks, causing motor or sensory deficits. Here, we report a case of a 42-year-old man presenting a lesion on the second finger of the right hand. The patient did not refer any previous trauma, tenderness, or sensorial nerve deficit. Histologic analysis showed a plexiform dermal lesion composed of enlarged nerve fascicles due to proliferation of spindle perineurial cells, arranged in onion-bulb-like structures. The proliferating cells showed positive membranous staining for epithelial membrane antigen and were negative for S100 protein, which highlighted residual Schwann cells. Fluorescence in situ hybridization studies revealed the loss of one signal for chromosome 22 probe in 15% of the spindle cells. In our report, we present the first case of cutaneous intraneural perineurioma, a benign tumor, which expands the morphological spectrum of cutaneous neural lesions.

A Rare Peripheral Nervous System Tumor: Soft Tissue Perineurioma of the Hallux

Perineuriomas are rare tumors of the peripheral nervous system that occur as either intraneural or extraneural lesions. Intraneural perineuriomas generally affect the major nerve branches in the upper extremity, whereas extraneural perineuriomas have a predilection for the subcutaneous tissues of the lower extremities. In this article, we describe the case of an adult patient who had a perineurioma localized to the foot. 4.

Intraneural reticular perineurioma of the hypoglossal nerve

Intraneural perineurioma or reticular perineurioma, which is 1 variant of extraneural perineurioma, has been rarely reported in the head and neck region. We report a case of a 52-year-old woman who wasseen with a swelling in the neck. A mass was found located on the medial aspect of the left submandibular gland and was palpated with a sponge-like texture. The mass was seen as a homogenous semisolid lesion on CT and ultrasound examination. Surgical exploration revealed expansion of the hypoglossal nerve. Microscopically, the tumor showed both pseudo-onion bulb, which is a feature of intraneural perineurioma, and reticular pattern with microcysts, which is a feature of reticular variant of extraneural perineurioma. The tumor cells were immunopositive for epithelial membrane antigen and human erythrocyte glucose transporter-1 (GLUT-1). An intraneural reticular perineurioma of the hypoglossal nerve should be included in the differential diagnosis of submandibular swelling.

Multiple orofacial intraneural perineuriomas in a patient with hemifacial hyperplasia

Perineurioma is a rare benign nerve sheath tumor derived of perineurial cells. There are two main types of perineurioma which differ histologically and clinically: intraneural and extraneural (soft tissue) perineurioma. Intraoral perineurioma is extremely rare. This report describes a case of multiple orofacial intraneural perineuriomas in a patient with hemifacial hyperplasia and discusses clinical, histologic, and ultrastructural features as well as differential diagnosis of perineuriomas, with emphasis on intraneural perineurioma.

Cutaneous perineurioma. Clinical and histological findings and differential diagnosis

Perineuriomas, composed almost exclusively of EMA (epithelial membrane antigen) positive cells, represent a rare and distinct entity in the spectrum of nerve sheath tumours. At present three subtypes, including intraneural and extraneural perineurioma as well as sclerosing perineurioma, can be distinguished; atypical and malignant perineuriomas are extremely uncommon. We analysed the clinicopathological and immunohistochemcial features of 13 cases of cutaneous perineurioma. The neoplasms arose in adult patients (age range from 18 to 71 years) and were seen on the hand (six cases), the thigh (three cases), the lower leg (two cases), the forearm (one case) and in perinasal location (one case). Morphologically, seven neoplasms showed features of dermatofibroma-like perineurioma, four lesions were consistent with sclerosing perineurioma, one cellular lesion resembled a solitary fibrous tumour, and one case was diagnosed as atypical/malignant cutaneous perineurioma; no local recurrences or tumour progression has been reported so far. The differential diagnosis of various variants of cutaneous perineurioma from other mesenchymal lesions as well as melanocytic and epithelial neoplasms is discussed.

Extraneural perineurioma of the face: an unusual cutaneous presentationof an uncommon tumour

Perineurioma is an uncommon, benign tumour of the peripheral nerve sheath that has two major clinicopathological forms - intraneural and extraneural. We present a case of extraneural perineurioma that occurred at an unusual site - the facial skin of a 70-year-old woman - which illustrates the wide, and potentially misleading, clinicopathological spectrum of this poorly recognized tumour.

Extraneural Retiform Perineuriomas: A Report of Four Cases

We present here four cases of extraneural perineurioma (EP), which occurred in 31, 32, 42 and 43 year old women in the left hand, right arm (2 cases) and right axillary regions, respectively. All tumors were well circumscribed, with a thin capsule. They were 2, 2, 1.5 and 1.5 cm in the largest diameter. Microscopically all tumors had a distinctive appearance composed of interconnected cords of cells which ran in a parallel fashion or formed a characteristically looking cellular lattice. These cords were composed of cells with tapered to stellate shaped nuclei having one or two inconspicuous nucleoli. The space between the cells of the lattice was edematous and empty looking, or it was composed of myxoid matrix, or it was filled with characteristically looking globular deposits of collagen extracellular matrix. These globular deposits of collagen extracellular matrix often indented the nuclei, giving them a stellar appearance. Immunohistochemically all tumors reacted positively with antibodies to epithelial membrane antigen. Antibodies to smooth muscle actin, muscle-specific actin, S-100 protein, cytokeratin AE1/AE3, cytokeratin CAM 5.2, and HMB-45 gave uniformly negative immunohistochemical results.