Excision of large median and ulnar nerve schwannomas: a case series.

OBJECTIVE: Schwannomas are benign, slow-growing tumors originating from Schwann cells in peripheral nerves, commonly affecting the median and ulnar nerves in the forearm and wrist. Surgical excision is the gold standard treatment. This study presents our treatment strategies and outcomes for large-sized ulnar and median nerve schwannomas at the forearm and wrist level. METHODS: From 2012 to 2023, we enrolled 15 patients with schwannomas over 2 cm in size in the median or ulnar nerve at the forearm and wrist. The study included 12 patients with median nerve schwannomas (mean age: 61 years) and 3 with ulnar nerve schwannomas (mean age: 68 years), with a mean follow-up of 26.9 months. RESULTS: After surgery, all patients with median nerve schwannomas experienced mild, transient numbness affecting fewer than two digits, resolving within six months without motor deficits. Ulnar nerve schwannoma excision caused mild numbness in two patients, also resolving within six months, but all three developed ulnar claw hand deformity, which persisted but improved at the last follow-up. Despite this, patients were satisfied with the surgery due to relief from severe tingling pain. CONCLUSIONS: Schwannomas of the median, ulnar, and other peripheral nerves should be removed by carefully dissecting the connecting nerve fascicles to avoid injury to healthy ones. Sensory deficits may occur but are unlikely to significantly impact quality of life. However, in motor-dominant nerves like the ulnar nerve, there is a risk of significant motor deficits that could affect hand function, though not completely. Therefore, thorough preoperative discussion and consideration of interfascicular nerve grafting are essential.

Plexiform Schwannoma Clinically Masquerading as Thrombosed Vein.

Plexiform schwannoma is a rare benign nerve sheath tumor usually located in trunk, head, neck, upper extremities and occasionally in lower extremities. It is usually less than 2 cm in size and generally affects young adults. The tumour is composed of schwann cells and exhibit a plexiform growth pattern both in gross or histologic examination and is frequently accompanied by multinodularity causing serpentine distortion. Plexiform neurofibroma commonly mimics plexiform schwannoma and it is important to differentiate between them, as recurrence and malignant potential are more common with plexiform neurofibroma. We present the case of a 14-year-old female with history of a nodular soft tissue mass over his right foot measuring 11 cm in length. A Doppler scan of the foot was suggestive of thrombosed superficial vein in right foot. The histological evaluation of the mass revealed Plexiform schwannoma. S-100 immunostaining is diffuse and strong confirming the diagnosis of Plexiform schwannoma.

Rapidly Growing Leiomyoma Mimicking Schwannoma of the Saphenous Nerve in the Lower Extremity: An Unusual Case Report.

Leiomyomas and schwannomas are both types of rare benign soft tissue tumours. Leiomyomas are more commonly found in the lower limbs than in the upper extremities, while schwannomas are rare peripheral nerve sheath tumours that can occur in different anatomical regions. However, they rarely occur in the saphenous nerve. This case study presents a 41-year-old female patient with a solitary mass lesion located deep in the soft tissue of the anteromedial lower extremity. The physical examination revealed a palpable, elastic-hard, mobile and non-tender mass. Magnetic resonance imaging (MRI) showed an oval-shaped subcutaneous mass on contrast-enhanced T1-weighted sections. The initial MRI images suggested a schwannoma, but the tumour was later confirmed to be a leiomyoma after total enucleation. An immunohistochemical study was performed for differential diagnosis. Solitary mass lesions in the lower extremities can be mistaken for various types of tumours and misdiagnosed and require histopathological examination and good radiological imaging for differential diagnosis. Complete surgical excision is usually a safe and effective treatment for leiomyomas.

Asymptomatic Purely Intracranial Vagal Schwannoma: Clinical Case Report and Literature Review.

Vagus nerve schwannoma is an infrequently occurring schwannoma, in which a distinct subtype exists wherein the tumor is confined to the cerebellomedullary cistern without invading the jugular foramen. This unique tumor is called purely intracranial vagal schwannoma. In this case report, we present a case of purely intracranial vagal schwannoma in its asymptomatic early phase, incidentally discovered during surgery performed on a patient with hemifacial spasm. Because of the small size of the tumor, we definitively recognized that it originated from the second rootlet on the caudal side. The tumor was totally resected uneventfully and a favorable prognosis was achieved. Furthermore, we conducted a comprehensive literature review to summarize the classification, origin, and surgical complications associated with this rare tumor type. Based on our literature review, we propose that: 1) the origin of tumor is related to the time of onset of symptoms, 2) nearly all purely intracranial vagal schwannomas can be entirely resected and favorable prognosis can be achieved, and 3) surgeons should be aware of potential cardiovascular complications during surgical procedures.

Thoracoscopic resection of a giant esophageal schwannoma: A case report and review of literature.

INTRODUCTION: Benign esophageal tumors are uncommon, accounting for approximately 2% of esophageal tumors. Esophageal schwannoma is a much rarer solid tumor with few cases reported in the literature. Open surgery is the surgical approach of choice for the treatment of esophageal tumors. With the advent of thoracoscopy, more and more countries are adopting a thoracoscopic approach to treat esophageal tumors, but there is still no clear surgical standard or modality for the treatment of esophageal tumors. PATIENT CONCERNS: A 50-year-old woman was admitted to our hospital. Over the past 2 months, her clinical presentation has included progressively worse swallowing disorder and weight loss. Gastroscopy showed an elevated lesion with a smooth surface visible 18 cm out from the incisors. An electron circumferential ultrasound endoscopy showed a hemispherical bulge with a smooth surface 18 to 23 cm from the incisor; the bulge originated from the intrinsic muscular layer and showed a heterogeneous mixed moderate ultrasound with a little blood flow signal and blue-green elastography in 1 of the sections measuring approximately 4 cm × 3 cm. Chest computed tomography (CT) showed a mass-like soft tissue shadow in the upper esophagus measuring approximately 39 mm × 34 mm, with a CT The lumen was compressed and narrowed, and the lumen of the upper part of the lesion was dilated, and the adjacent trachea was compressed and displaced to the right. INTERVENTIONS: After completion of the examination, assisted by artificial pneumothorax and thoracoscopic resection of esophageal masses were performed. DIAGNOSIS AND OUTCOMES: Postoperative pathology report: Mesenchymal-derived tumor (esophagus), combined with immunohistochemical staining results and morphologic features supported schwannoma. The patient's postoperative course was calm. The patient's postoperative dysphagia subsided. CONCLUSION: We describe a case of successful treatment of a schwannoma of the upper esophagus using artificial pneumothorax-assisted VATS. The combined use of Sox10 and S100 helps to improve the sensitivity and specificity of schwannoma diagnosis. Damage to the esophageal lining was avoided by mixed thoracoscopic and endoscopic exploration. This approach can also be applied to benign esophageal tumors in the thoracic and subthoracic segments, leading to better minimally invasive results.

Cellular Schwannoma Mimicking a Nodular Melanoma on the Sole of the Foot, an Avoidable Diagnostic Pitfall.

ABSTRACT: We report a rare case of cellular schwannoma (CS) manifesting as an ulcerated nodular lesion, mimicking spindle cell melanoma on the sole of the foot. CS, a benign variant of schwannoma, typically occurs in deep soft tissues but can rarely present cutaneously. The diagnosis of CS heavily relies on histopathological examination and immunohistochemical staining for specific markers such as SOX10 and S100. In this case, initial clinical suspicion of nodular melanoma was confirmed on biopsy, which revealed a spindle cell neoplasm positive for SOX10 and negative for melanocytic markers. Misdiagnosis of nodular melanoma was averted through complete excision. CS diagnosis demands careful consideration due to its resemblance to other spindle cell neoplasms, especially melanoma. Meticulous histopathological evaluation and immunostaining are important to differentiate CS from similar lesions, ensuring accurate diagnosis and appropriate management. This report contributes valuable insights into the diagnostic challenges and management of CS, particularly in unusual cutaneous presentations.

Comprehensive analysis of diagnosis and treatment in 99 cases of abdominal Schwannoma.

PURPOSE: Schwannoma is a rare mesenchymal tumor. In this study, we analyzed clinicopathologically 99 schwannomas.This retrospective study delves into the clinical, pathological, and immunohistochemical dimensions of abdominal schwannomas. RESULTS: A cohort of 99 cases, comprising 4 malignant and 95 benign schwannomas, was meticulously examined. Clinical analysis revealed a notable gender distribution (1:1.7, male to female) and an average age of 58.5 years. The majority of cases were asymptomatic. A cohort of 99 cases, comprising 4 malignant and 95 benign schwannomas, was meticulously examined. Clinical analysis revealed a notable gender distribution (1:1.7, male to female) and an average age of 58.5 years. The majority of cases were asymptomatic. Tumor sizes ranged from 0.5 to 30 cm, with distinct locations in the stomach for most benign cases and the abdomen/small intestine for malignancies. Initial misdiagnoses were frequent. Pathological evaluations revealed distinct features, including Antoni A and B patterns, spindle cells, and lymphatic sheath structures in benign schwannomas. Malignant cases exhibited atypical cells, ulcers, and invasive growth. Immunohistochemical markers, such as S100, SOX10, and vimentin, consistently demonstrated positivity by contributing to accurate diagnoses. Treatment outcomes indicated a poor prognosis in malignant cases, with overall survival ranging from 10 to 41 months. Conversely, benign cases displayed no recurrence or metastasis during follow-up, despite atypical behaviors. CONCLUSION: This study underscores the rarity of abdominal schwannomas and underscores the need for a comprehensive diagnostic morphology and immunohistochemistry. SOX10 emerges as a crucial and specific marker for accurate diagnosis. Further research is imperative to refine diagnostic protocols and enhance our understanding of the clinical behavior of abdominal schwannomas.

Intralabyrinthine Schwannoma Mimicking Posterior Canalithiasis.

Intralabyrinthine schwannomas are a rare subgroup of vestibular schwannomas located within the membranous labyrinth of the inner ear and are known for their variable clinical presentations and symptoms. In the present study, we report on a patient with a persistent history of dizziness and positional vertigo, who was misdiagnosed with posterior canalithiasis. As hearing loss was not developed until late in the disease course, the patient was not properly diagnosed until magnetic resonance imaging revealed an intralabyrinthine schwannoma, which was not discovered on earlier imaging. In addition to the unusual clinical presentation, we describe the audio-vestibular profile of our patient. We suggest that a thorough vestibular evaluation, including caloric testing and a careful examination of the inner ear on imaging, is warranted in cases of treatment of refractory vertigo, even in patients where a diagnosis seems certain.

Primary schwannoma of the thyroid gland: analysis of case characteristics and review of the literature.

BACKGROUND: To improve the characteristics of primary thyroid schwannomas (PTS) and to provide reference basis for clinical diagnosis and treatment. METHODS: PubMed was searched for case reports of PTS up to December 2022 using the search terms "Thyroid nerve sheath tumor" or "Thyroid schwannoma" or "Thyroid Neurilemmoma", respectively. 34 cases were screened. RESULTS: PTS can occur at any age, nodules averaged 3.9 cm. The most common symptoms were voice change and dysphagia. Fine needle aspiration cytology showing spindle-shaped cells should be considered for schwannoma. Most cases underwent thyroid lobectomy or nodule removal with a good prognosis. Tissue types with both Antoni A and Antoni B features are common. Positive immunohistochemical staining for S-100 protein, CD34 and waveform proteins helped confirm the diagnosis. CONCLUSIONS: Positive immunohistochemistry for S-100 and wave proteins helps confirm the diagnosis. Preoperative diagnosis is challenging, but pathology and immunohistochemical staining are the gold standard for diagnosis. The first choice of treatment is surgical resection of the nodules, the prognosis is good.

Image features and clinical analysis of retroperitoneal pelvic schwannoma: a case report.

BACKGROUND: Schwannomas are benign usually encapsulated nerve sheath tumors derived from the Schwann cells, and affecting single or multiple nerves. The tumors commonly arise from the cranial nerves as acoustic neurinomas but they are extremely rare in the pelvis and the retroperitoneal area. Retroperitoneal pelvic schwannomas often present with non-specific symptoms leading to misdiagnosis and prolonged morbidity. CASE PRESENTATION: We report the case of a 59-year-old woman presenting with a feeling of heaviness in the lower abdomen who was found to have a retroperitoneal pelvic schwannoma originating from the right femoral nerve. She had a history of two resections of peripheral schwannomas at four different sites of limbs. After conducting magnetic resonance imaging, this pelvic schwannoma was misdiagnosed as a gynecological malignancy. The tumor was successfully removed by laparoscopic surgery. Pathological analysis of the mass revealed a benign schwannoma of the femoral nerve sheath with demonstrating strong, diffuse positivity for S-100 protein. CONCLUSIONS: Although retroperitoneal pelvic schwannoma is rare, it should be considered in the differential diagnosis of pelvic masses, especially in patients with a history of neurogenic mass or the presence of neurogenic mass elsewhere.

Giant Common Peroneal Nerve Schwannoma Mimicking Synovial Sarcoma: An Unusual Case Report.

Schwannoma, also known as neurilemmoma or Schwann cell tumor, is one of the most common neoplasms of the nerve sheath which usually appears at the head, neck, or upper extremity. Schwannoma occurrence in the lower extremity originating from the common peroneal nerve is rarely reported according to literary findings. We report a case of a 32-year-old man who presented with a 6-month history of a growing lump in the left knee. MRT revealed a well-defined 9.6 cm × 7.8 cm × 6.5 cm multilobular mass of heterogeneous consistency with areas of necroses with a likely diagnosis of synovial sarcoma. After surgery, a final histopathological assessment of the tumor demonstrated Antoni A and B patterns with nuclear palisading, hallmarks of a schwannoma. Postoperatively the patient suffered a neurological complication-impaired dorsiflexion of the left foot. The patient started immediate physiotherapy in the Department of Rehabilitation. Three weeks after the operation, gradual improvement in neurological function was observed. To date, complete tumor excision combined with microscopic analysis and immunohistochemical staining remains the gold standard in diagnosing and treating a peripheral nerve schwannoma. Moreover, the use of additional nerve monitoring tools during surgery could help to prevent complications.

Laryngeal schwannoma masquerading as malignancy.

Laryngeal schwannoma is a rare type of neurogenous tumour with a non-specific presentation. We present a case of a middle-aged man with issues of hoarseness, globus sensation and intermittent episodes of throat pain. The Hopkins examination showed right vocal fold irregularity with fullness in the right ventricle. The contrast-enhanced CT neck revealed an ill-defined lesion with contrast uptake extending into the paraglottic region with no neck node involvement. Considering the clinical presentation of hoarseness, throat pain and globus with imaging revealing contrast enhancement of lesion, direct laryngoscopy and biopsy were planned to rule out malignancy. Intraoperatively, a well-defined submucosal capsulated swelling became apparent after incision and dissection of the mucosa over the right vocal fold. A complete excision of the swelling was done with microlaryngeal instruments without tracheostomy. The histopathological report was suggestive of schwannoma. The literature review discusses clinical presentation, location, imaging features and management strategy.

Historical Development of Diagnostic Criteria for NF2-related Schwannomatosis.

NF2-related schwannomatosis (NF2; previously termed neurofibromatosis type 2) is a tumor-prone disorder characterized by development of multiple schwannomas and meningiomas. The diagnostic criteria of NF2 have been regularly revised. Clinical criteria for NF2 were first formulated at the National Institutes of Health Consensus Conference in 1987 and revised in 1990. Revised criteria were also proposed by the Manchester group in 1992 and by the National Neurofibromatosis Foundation (NNFF) in 1997. The 2011 Baser criteria improved the sensitivity of diagnostic criteria, particularly for patients without bilateral vestibular schwannomas. Revisions to the Manchester criteria were published in 2019, with replacement of "glioma" by "ependymoma," removal of "neurofibroma," addition of an age limit of 70 years for development of vestibular schwannomas, and introduction of molecular criteria, which led to the most widely used criteria. In 2022, the criteria were reviewed and updated by the international committee of NF experts. In addition to changes in diagnostic criteria, the committee recommended the use of "schwannomatosis" as an umbrella term for conditions that predispose to schwannomas. Each type of schwannomatosis was classified by the gene containing the disease-causing pathogenic variant. Molecular data from NF2 patients led to further clarification of the diagnostic criteria for NF2 mosaic phenotypes. Given all these changes, the diagnostic criteria of NF2 may be confusing. Herein, to help healthcare professionals who diagnose NF2 conditions in the clinical setting, we review the historical development of diagnostic criteria.

[Features of course of pain syndrome in patients with schwannomatosis]. / Osobennosti techeniya bolevogo sindroma u patsientov s shvannomatozami.

OBJECTIVE: To identify the characteristics of pain syndrome in patients with schwannomas depending on genetic predisposition. MATERIAL AND METHODS: The study included 46 patients with peripheral, spinal and intracranial schwannomas, corresponding to the schwannomatosis phenotype according to the 2022 clinical criteria. All patients underwent sequencing of the LZRT1, Nf2 and SMARCB1 and a copy number study in the NF2. RESULTS: The most severe widespread pain was observed in patients with pathogenic LZRT1 variants, while patients with mosaic variants may not even have local tumor-related pain. Patients with SMARCB1variants may have no pain or have localized pain that responds well to surgical treatment. CONCLUSION: Further studies of the molecular features of schwannomatosis and driver mutations in the pathogenesis of pain are necessary to improve the effectiveness of pain therapy in this group of patients. Schwannomatosis is a disease from the group of neurofibromatosis, manifested by the development of multiple schwannomas. Neuropathic pain is one of the main symptoms characteristic of peripheral schwannomas, however, the severity and prevalence of the pain syndrome does not always correlate with the location of the tumors. According to modern concepts, the key factors influencing the characteristics of the pain syndrome are the target gene and the type of pathogenic variant. The most severe widespread pain is observed in patients with pathogenic variants in the LZRT1 gene, while patients with mosaic variants may not even have local pain associated with tumors. Patients with variants in SMARCB1 may have no pain or localized pain that responds well to surgical treatment.

Esophageal schwannoma mimicking non-functional parathyroid adenoma on 99mTc-sestamibi imaging: a case report.

Technetium-99m sestamibi single-photon emission computed tomography/computed tomography (99mTc-sestamibi SPECT/CT) is a mainstay of the pre-operative localization of parathyroid lesions. We report here the case of a 30 year-old woman with a fortuitously discovered 2 cm cervical mass for which a parathyroid origin was originally suspected due to its retro-thyroidal localization and a personal history of nephrolithiasis. Normal serum calcium and parathyroid hormone (PTH) levels excluded primary hyperparathyroidism, raising suspicion of a non-functional parathyroid adenoma, and SPECT/CT imaging showed that the mass was 99mTc-sestamibi-avid. Fine-needle aspiration (FNA) was performed; cytology was non-diagnostic but the needle washout was negative for thyroglobulin, calcitonin and PTH, arguing against a thyroidal or parathyroidal origin of the mass. Core needle biopsy revealed a schwannoma, ostensibly originating from the recurrent laryngeal nerve; upon surgical resection, it was finally found to arise from the esophageal submucosa. This case illustrates the fact that endocrinologists, radiologists, nuclear medicine, head and neck, and other specialists investigating patients with cervical masses should be aware that schwannomas need to be considered in the differential diagnosis of focal 99mTc-sestamibi uptake in the neck region.