Plexiform Schwannoma Research Articles

Plexiform schwannoma: A rare histological entity at a rare site

Plexiform schwannoma is an uncommon Schwann cell tumor, characterized by its multinodular growth with a plexiform histological pattern. Plexiform schwannoma arises from the soft tissues around the head and neck region. Few cases are associated with neurofibromatosis type 2 or schwannomatosis. We present a rare case of this tumor in a 25-year-old man, who presented with a discrete movable, deep seated nodule, associated with pain and tenderness over the spinal region, across the seventh cervical vertebrae with chief complaints of dizziness and vertigo for the last one year.

P28 Congenital Cellular Plexiform Schwannoma Masquerading as Infantile Haemangioma – A Case Report

Abstract Introduction Schwannomas are tumours of the peripheral nerve sheath that rarely metastasize but are prone to recurrence. They sometimes occur in the context of syndromes such as neurofibromatosis type 2, Carney complex, and schwannomatosis. Congenital schwannomas appear as an erythematous patch that increases in size in the first few weeks and can be easily mistaken for infantile haemangioma (IH). Case A 3-month-old boy was referred to us for suspected IH on the dorsum of his right hand. At birth, he had a slightly erythematous patch but was rapidly increasing in size. Initial ultrasound done locally suggested it may be an IH based on the demonstration of arterial and venous flows. He was otherwise well, and there were no concerns about his growth or development. On examination, he had a firm mass, measuring 3 cm in diameter, that was not clinically in keeping with a vascular anomaly. Our repeated ultrasound showed a solid tumour, possibly fibrosarcoma or myofibroma. Biopsy confirmed cellular plexiform schwannoma and he underwent excision. The results of whole genome sequencing are pending (SMARC-1 and NF), and he remains under the care of the oncology team. Conclusion Clinicians assessing infants with “haemangiomas” have a difficult task of differentiating them from other soft tissue tumours. The clinical appearance of vascularity, along with high vascular flow seen on the imaging, cannot always rule out soft tissue tumours. Assessment of firmness can be somewhat subjective, but any vascular lesion that is very firm should be investigated further.

Plexiform Schwannoma of Digital Nerve.

Plexiform schwannoma is an uncommon benign tumour that grows in a plexiform pattern. We report a 47-year-old man with a mass on the palmar aspect of the metacarpophalangeal joint of the right index finger that had been growing gradually for more than 10 years. The mass was palpated from the distal carpal tunnel to the ulnar aspect of the proximal interphalangeal joint of the index finger, with tingling and numbness sensation. The tumour was a multinodular tumour involving the first common palmar digital nerve to the ulnar proper palmar digital nerve. It was resected and reconstructed with a sural nerve graft. Plexiform schwannoma is rare in the digital nerve, with only six cases reported. Generally, classic schwannomas can be enucleated without causing neurologic deficits; however, plexiform schwannoma may require nerve resection. There have been reports of recurrence of plexiform schwannoma; definitive resection and long-term follow-up are necessary. Level of Evidence: Level V (Therapeutic).

Staged surgical excision of a premaxillary plexiform schwannoma causing nasal obstruction and deformity

While schwannomas of the head and neck are not uncommon, plexiform type schwannomas are rare with very few nasal cases described in the literature

Surgical treatment of multiple plexiform schwannomas arising from the superficial radial nerve: a case report

Schwannoma, or neurilemmoma, is a benign neoplasm that arises from Schwann cells, which surround peripheral, cranial, and autonomic nerve sheaths. Schwannoma has been reported to occur mainly as a singular lesion of the sacral nerve or sciatic nerve in young adults. Plexiform schwannoma, a subtype of schwannoma, is a rare neoplasm known to account for 2% to 5% of total schwannomas. Schwannoma of the upper extremities is relatively rare and is reported to occur mostly in the ulnar nerve. We report, with a literature review, a case of 4.2-cm and 2.8-cm symptomatic multiple plexiform schwannomas that occurred in the superficial radial nerve and were treated without neurologic sequelae by surgical resection.

A Rare Case of Plexiform Schwannoma of the Little Finger and Its Management: A Case Report

Schwannomas are tumors of the Schwann cells found in the myelin sheath. They cause 5% of all benign soft-tissue cancers, occur equally in males and females, and occur later in life. Since they remain asymptomatic, diagnosing and treating them becomes challenging; current guidelines recommend imaging followed by excision. Here, we present a case of a 19-year-old male who presents in an outpatient setting with a history of painless swelling of the fifth digit for the past four years. Past medical history and physicals are unremarkable. Microscopic findings from fine-needle aspiration cytology (FNAC) confirmed the schwannoma diagnosis, showing loosely arranged spindle cells with elongated nuclei with pointed ends dispersed within the myxoid stroma.

Skin lesions in neurofibromatosis type 2: diagnostic and prognostic significance of cutaneous (plexiform) schwannomas

BackgroundNeurofibromatosis type 2 (NF2) is a genetic disease characterized by the appearance of multiple tumours in the nervous system. Cutaneous lesions are common and may provide useful diagnostic and prognostic information, but they have not been widely studied.ObjectivesTo characterize cutaneous lesions in a Spanish cohort of patients with NF2 and investigate associations with clinical and genetic severity.MethodsWe studied the clinical and histologic characteristics of cutaneous lesions in 49 patients with NF2 and analysed correlations with phenotype‐ and genotype‐based severity scores. We collected information on the presence/absence of cutaneous lesions, location, age at onset, type of lesion, and histologic features. We also studied level of systemic involvement and genetic mutations involved.ResultsForty‐nine patients (31 women [63.3%] and 18 men [36.7%]) were analysed, and 33 (67.3%) had cutaneous lesions presumed to be schwannomas. According to their clinical form, they were distributed as follows: 24 patients (48%) had deep tumours, 21 (42%) had plaque‐like lesions, and 3 (6%) had superficial tumours. Histologic examination from 27 lesions analysed out 23 patients showed classic schwannoma or hybrid schwannoma‐neurofibroma features in the 8 deep tumours biopsied and plexiform schwannoma features in the 17 plaque‐like lesions and the 2 superficial tumours analysed. Early onset (first 2 decades of life) was reported by all patients with plaques and superficial tumours. In our cohort, 100% of the patients with plaque‐like lesions and superficial tumours with microscopic features of plexiform schwannoma were in the 2 groups with the most severe clinical phenotypes, and 82.6% of them were in the 3 most severe genotype‐based classes.Conclusions and RelevanceCutaneous lesions, specially plexiform schwannomas, are common in NF2, and they usually appear at an early age providing useful diagnostic and prognostic information. These tumours are part of the spectrum of cutaneous manifestations in this disease. Although its diagnostic and prognostic value has been pointed out, there are few studies focussed on their analysis.

Cutaneous plexiform schwannoma of the digit- A case report

Schwannoma is a most common type of benign peripheral nerve sheath tumor in adults. Plexiform schwannoma [PS] are relatively rare with reported incidence of only 5%. Skin and soft tissues are primarily involved structure. It is rare to find them on the digits. We report a case of expansile swelling on the digit. The definitive diagnosis was revealed only after exision biopsy. Schwannoma should be included in the differential diagnosis of any swelling arising from the digits.

Plexiform Schwannoma at an Unusual Site Involving the Angle of Mouth

Plexiform schwannoma (PS) is a rare benign encapsulated peripheral nerve sheath tumor characterized by a plexiform pattern of intraneural growth often with a multinodular appearance. It usually presents as a solitary mass with a strong predilection for young adults between 20 and 50 years. Despite its common presentation in the head and neck region, involvement of the lip is extremely rare. Multiple cutaneous PSs are commonly associated with Neurofibromatosis type 2 or Schwannomatosis. To date, only a few cases of PS involving the lip have been reported. Here in we report another unusual case of PS involving the angle of mouth which was removed completely by surgical excision without any recurrence seen at 1-year post-surgery.

Plexiform Schwannoma Masquerading as an Appendageal Tumor

Plexiform Schwannoma Masquerading as an Appendageal Tumor

Challenging Management of Plexiform Schwannoma and Plexiform Neurofibroma

Plexiform variants of neurofibromas and schwannomas are rare and typically arise in superficial soft tissues in the head and neck region. The treatment of these tumors is challenging and no generally accepted guidelines exist for their optimal management. The purpose of this study was to review the management and longterm prognosis of head and neck plexiform neurofibromas and schwannomas at 2 tertiary care academic hospitals in Finland over a 31-year period. The pathology files were searched for plexiform neurofibromas and schwannomas between the years 1990 and 2020. The case notes were reviewed for full management details. Two plexiform schwannomas and 6 plexiform neurofibromas were identified. Five of the 6 plexiform neurofibromas were managed operatively. All patients with a surgically managed plexiform neurofibroma underwent multiple operations. Sclerotherapy abolished 1 patient's cutaneous plexiform neurofibromas. The management of plexiform neurofibromas and plexiform schwannomas remains challenging. Sclerotherapy may offer a promising management option for cutaneous plexiform neurofibromas.

Schwannomatosis of the tibial nerve

<p class="abstract">Schwannoma is the most common type of benign tumor arising from the sheaths of the peripheral nerves. It occurs as a solitary tumor in most cases, but when it appears in multiple forms, it is necessary to differentiate it from plexiform schwannoma, schwannomatosis, neurofibroma and malignant peripheral nerve tumors. The authors experienced schwannomatosis in the tibial nerve without the features of neurofibromatosis type 2, so here we present a case report and literature review.</p>

A case of peripancreatic plexiform schwannoma

BackgroundPlexiform schwannoma is one of the least common variants of schwannoma, accounting for only 5% of all schwannoma cases. It generally occurs in the skin and subcutaneous tissues and is uncommon in deep soft tissue or viscera. We present an extremely rare case of plexiform schwannoma arising from the peripancreatic plexus.Case presentationA 29-year-old man presented with hyperglycemia detected during a medical checkup. He was diagnosed with type 1 diabetes based on the clinical findings and laboratory tests. During the diagnostic process for diabetes, a 2.5 cm mass was incidentally detected in the pancreas by abdominal ultrasound. Contrast-enhanced computed tomography revealed a mass that was gradually enhanced at the body and tail of the pancreas. Magnetic resonance imaging revealed low signal intensity of the mass on T1-weighted images and high signal intensity on T2-weighted and diffusion-weighted images. Magnetic resonance cholangiopancreatography showed no abnormal findings in the main pancreatic duct. Endoscopic ultrasonography (EUS) showed a lobulated, low-echoic mass with a clear boundary. EUS-guided fine needle biopsy was performed, and spindle-shaped cells that were diffusely immunopositive for S-100 and negative for c-kit and desmin were detected, resulting in a diagnosis of a neurogenic tumor arising from the pancreas or the peripancreatic nerve plexus. The patient underwent laparoscopic spleen-preserving distal pancreatectomy. Although the tumor was connected to the splenic plexus, the splenic artery could be divided along its adventitial plane. Macroscopic findings of the excised tumor consisted of multiple yellowish-white nodules, and its histopathological features were consistent with plexiform schwannoma. There was no pancreatic tissue on the dorsal surface of the tumor, which suggested that the tumor arose from the peripancreatic nerve plexus.ConclusionsThe findings documented herein can aid in the differential diagnosis of peripancreatic schwannoma and in planning appropriate treatment.

PLEXIFORM SCHWANNOMA INVOLVING THE ANTERIOR MANDIBLE

<h3>BACKGROUND</h3> Schwannomas and neurofibromas are common benign neoplasms originating from the peripheral nerves. These neoplasms originating in the oral and para-oral tissues, especially involving the jaw, are extremely rare. Plexiform schwannoma is a unique variant in which the Schwann cells demonstrate a unique plexiform pattern. A literature search revealed only 2 case reports of plexiform schwannoma involving the jaws. <h3>CASE REPORT</h3> A 47-year-old male patient was referred for consultation by his dentist for evaluation and diagnosis of a radiolucency in the anterior mandible with no apparent odontogenic/clinical etiology. The patient complained of sensitivity in this region and occasional radiating pain. Clinical examination showed no signs of infection or inflammation. The patient denied any known medical disease or history of surgeries. Cone beam computed tomography examination revealed a large, well-defined, hypodense, partially corticated lesion in the anterior mandible with evidence of impingement of the facial cortex, resulting in a scooped-out defect. The radiologic differential interpretation included peripheral ameloblastoma and peripheral giant cell granuloma. An incisional biopsy was recommended to determine the nature of this entity. Microscopic examination revealed a multicircumscribed, lobular mass bounded by a thin fibrous connective tissue capsule. Each lobule was composed of streaming fascicles of spindle-shaped cells, some of which formed a palisading arrangement. Immunohistochemistry was positive for protein S-100 and epithelial membrane antigen, which confirmed the diagnosis of plexiform schwannoma. <h3>DISCUSSION/CONCLUSIONS</h3> This is an unusual case of a unique variant of schwannoma, in this case a plexiform type, which is an extremely rare neurogenic neoplasm. This atypical presentation and location of the lesion, which mimics other peripheral benign neoplasms, highlights the importance of a systematic workup with the aid of the appropriate diagnostic tools for ideal patient care. It demonstrates the important role of immunohistochemistry to confirm the nature of this entity.

Review of Pediatric Head and Neck Neoplasms that Raise the Possibility of a Cancer Predisposition Syndrome.

Cancer predisposition syndromes (CPS) are generally heritable conditions that predispose individuals to develop cancer at a higher rate and younger age than their representative general population. They are a significant cause of cancer related morbidity and mortality in the pediatric population. Therefore, recognition of lesions that may be associated with a CPS and alerting the clinicians to its implications is a crucial task for a diagnostic pathologist. In this review we discuss benign pediatric head and neck lesions associated with CPS namely: odontogenic keratocyst, juvenile nasopharyngeal angiofibroma, ossifying fibroma of the jaw, paraganglioma, plexiform neurofibroma, plexiform schwannoma, mucosal neuroma, and nevus sebaceous syndrome; along with malignant tumors such as squamous cell carcinoma. Several head and neck melanocytic, endocrine, and central nervous system tumors can also be associated with CPS; they are beyond the scope of this article. Nasal chondromesenchymal hamartoma is discussed elsewhere in this issue.

Visceral plexiform schwannoma: A case series.

Plexiform schwannoma (PS) is a benign tumour of the peripheral nerve sheath that is typically found in the skin. Fewer than 15 cases of visceral PS have been reported to date in both adults and children. We herein discuss a series of 3 patients (2 male and 1 female) with abdominal PS, aged 10-16 years (mean age, 12 years). All the patients had an acute presentation with abdominal pain, which was associated with rectal bleeding in 1 case and with walking difficulties in 1 case. Radiological investigations included abdominal magnetic resonance imaging (MRI) and computed tomography, along with neurofibromatosis screening (cerebral MRI and dermatological evaluation). Complete removal of the mass was possible in 2 of the patients (in 1 case by laparoscopically assisted surgery). Follow-up was uneventful. Abdominal PS is a rare occurrence. Due to its possible association with neurofibromatosis, the diagnosis of PS should prompt an investigation for other manifestations of this disorder.

Plexiform Schwannoma Masquerading as Giant Cell Tumor of Tendon Sheath- A Case Report

Plexiform schwannoma is a rare benign variant of Schwann cell tumor characterised by multinodular plexiform growth pattern. Usual location of this tumor includes trunk, head, neck and upper extremities but it may rarely be found in lower extremities. It generally affects young adults with no sex predilection. We report a case of 37 years old male who presented with gradually progressive swelling of right little finger of 28years duration that was diagnosed as giant cell tumor of tendon sheath clinically, radiologically and intraoperatively. Authors wish to discuss the case due to its clinical rarity and diagnostic difficulties due to many common histological mimickers at that site.

Extremely rare case of retropharyngeal space benign plexiform schwannoma - Excised through Smith- Robinson Approach

Background: Approximately 25–45% of schwannomas are typically slow-growing, encapsulated, and noninvasive tumors that occur in the head-and-neck region where they rarely involve the retropharyngeal space. Here, we report deep-seated benign plexiform schwannoma located in the retropharyngeal C2-C5 region excised utilizing the Smith-Robinson approach.Case Description: A 30-year-old male presented with dysphagia and impaired phonation attributed to an MR documented C2-C5 retropharyngeal schwannomas. On examination, the lesion was soft, deep seated, and extended more toward the right side of the neck. Utilizing a right-sided Smith-Robinson’s approach, it was successfully removed. The histopathology confirmed the diagnosis of a plexiform schwannoma.Conclusion: Retropharyngeal benign plexiform schwannomas are rare causes of dysphagia/impaired phonation in the cervical spine. MR studies best document the size and extent of these tumors which may be readily resected utilizing a Smith-Robinson approach.

Giant intradural plexiform schwannoma of the lumbosacral spine - a case report and literature review

BackgroundPlexiform schwannoma (PS), variant of schwannoma, often involves multiple fascicles as plexiform neurofibroma, and is usually located superficially on the dermis and subcutaneous layers. Spinal PS is extremely rare, and there is insufficient information on its natural course and treatment strategy. We describe the clinical features and treatment of giant intradural PS at the lumbosacral spine.Case presentationA 66-year-old man presented with leg pain, paresthesia, and weakness for 2 years. Magnetic resonance imaging demonstrated a large mass lesion involving a continuous multi-lobulated bead-like mass and a cystic portion from L1 to S3. The lesion was iso-intense on T2-weighted images (WI), iso- to slightly low-intense on T1-WI, and heterogeneous enhancement on contrast-enhanced T1-WI. The large mass lesion had three portions, including a cystic mass at L1, continuous multi-lobulated bead-like mass with a cystic portion from L2 to S1, and multi-lobulated mass from S2 to S3, which were identified with severe adhesions with cauda equina on operative assessment. Grossly total extirpation was achieved at the lumbar spine, and remained three round shaped small masses at the lumbar area and a multi-lobulated round masses from S2 to S3 involving nerves related with motor function of the lower extremities and anal sphincter, respectively. Histological examination revealed multinodular or plexiform growth pattern composed of spindle-shaped tumor cells, which were diffusely and strongly positive for S100 protein with KI67 < 1%. There were no recurrence of preoperative symptoms and changes of the remained masses over a 2-year follow-up period.ConclusionSubtotal extirpation to minimize neural deficits and close observation can be considered an appropriate treatment strategy for a giant spinal PS considering its benign prognosis and histological features, with a high risk of neurological damage during surgery.

Plexiform Schwannoma of the Oral Cavity: Report of Eight Cases and a Review of the Literature.

Plexiform schwannoma represents an unusual schwannoma variant, characterized by multinodular growth grossly and/or microscopically. A review of the English-language literature reveals only 28 previously reported cases involving the oral cavity, and herein we present 8 additional cases. Among these 36 patients, the average age at diagnosis was 28 years (range 5 to 62 years), with a female-to-male ratio of 1.4:1. The most frequently involved sites were the tongue (n = 13) and lip (n = 11). Lesion duration prior to presentation averaged 5.3 years (range, 6 weeks to 26 years). The average lesion size was 2.1 cm (range, 0.3 to 16 cm). The typical clinical presentation was a painless mass, although infrequent findings included pain/discomfort, paresthesia, difficulty chewing, and limited buccal mobility. All cases clinically appeared as a solitary mass or localized cluster of tumor nodules, with the exception of one patient who had neurofibromatosis 2 (NF2) and exhibited two distinct nodules on the tongue and buccal mucosa. In addition, extraoral neural neoplasms were evident in four patients, including three with NF2. Typical microscopic findings included multiple well-circumscribed tumor nodules, each surrounded by a perineurium-derived capsule with immunoreactivity for epithelial membrane antigen. The nodules contained characteristically bland and diffusely S-100-positive spindle cells arranged in Antoni A and B patterns; however, modest nuclear pleomorphism was evident in three cases. Most patients (n = 23) were treated by excision or enucleation and curettage, and three patients experienced recurrence. Unlike plexiform neurofibromas, plexiform schwannomas exhibit only a weak association with neurofibromatosis and have no known malignant potential.