Solitary Schwannoma Research Articles

Benign Solitary Schwannoma of the Cheek: A Case Report and a Review of the Literature.

Schwannomas are generally known to be benign tumors that arise from Schwann cells. The most frequently encountered tumors of this type in ENT are vestibular schwannomas or acoustic neuromas. However, head and neck localization, although rare, has been documented in the literature. We present the case of a 13-year-old girl who presented with chronic swelling of the left cheek, leading to aesthetic discomfort. Clinical examination objectified a palpable swelling on both the external and internal sides of the left cheek. No other abnormalities were detected during the clinical examination. Ultrasound of the soft tissues identified the left cheek swelling as corresponding to a subcutaneous cyst. No further investigations were indicated for this patient. The treatment consisted of surgical excision via an intraoral approach with an internal buccal incision. Histological analysis confirmed the diagnosis of schwannoma. Schwannoma, a benign neurologic tumor, is rarely located in the face, particularly in the jaw. Its diagnosis is confirmed through histopathological examination, and treatment typically involves complete surgical removal when feasible.

Retraction: A Rare Case of Solitary Schwannoma of Submandibular Gland.

[This retracts the article DOI: 10.7759/cureus.21373.].

Massive spontaneous hemothorax caused by benign solitary schwannoma

Massive spontaneous hemothorax caused by benign solitary schwannoma

YAP1-MAML2 fusion in a pediatric NF2-wildtype intraparenchymal brainstem schwannoma

Biallelic inactivation of NF2 represents the primary or sole oncogenic driver event in the vast majority of schwannomas. We report on a four-year-old female who underwent subtotal resection of a right medullary intraparenchymal schwannoma. RNA sequencing revealed an in-frame fusion between exon 5 of YAP1 and exon 2 of MAML2. YAP1-MAML2 fusions have previously been reported in a variety of tumor types, but not schwannomas. Our report expands the spectrum of oncogenic YAP1 gene fusions an alternative to NF2 inactivation to include sporadic schwannoma, analogous to what has recently been described in NF2-wildtype pediatric meningiomas. Appropriate somatic and germline molecular testing should be undertaken in all young patients with solitary schwannoma and meningioma given the high prevalence of an underlying tumor predisposition syndrome. In such patients, the identification of a somatic non-NF2 driver alteration such as this newly described YAP1 fusion, can help ascertain the diagnosis of a sporadic schwannoma.

A case of a giant thoracic schwannoma

Background: Giant solitary schwannomas are rare, benign, and typically slow-growing tumors reaching up to 20 cm in size.Case Description: A 43-year-old male presented with shortness of breath and chest pain. The thoracic MRI showed a giant mass 15 cm in diameter filling the left chest cavity. The lesion was resected utilizing intrathoracic approach and required a multilevel approach. Vertebrectomy with instrumented fusion was performed. The pathological diagnosis was benign schwannoma without nuclear atypia. Postoperatively, the patient fully recovered without sequelae.Conclusion: A 43-year-old male presented with a 15 cm diameter chest mass that proved to be a schwannoma that was resected without long-term sequelae.

Clinical results after surgical resection of benign solitary schwannomas: A review of 150 cases

IntroductionPeripheral nerve schwannomas are the most common nerve tumors. While they are efficiently treated with surgery, the risk of neurological complications, especially sensory deficits, remains debated. HypothesisWe postulate that rates of post-operative sensory deficits in peripheral schwannoma surgery are low and are not increased in schwannomas of the hand, in which preservation of discriminative tact is of prime functional importance. Materials and methodsA retrospective multicenter study was carried out on 150 patients with an isolated peripheral schwannoma operated between 2002 and 2018, including 11 patients with schwannomas of the hand. All cases were reviewed preoperatively and postoperatively with a detailed exam of the neurological status. ResultsMost schwannomas were located in the lower limbs (58%). The two main affected trunks were the posterior tibial nerve in the lower limb and the median nerve in the upper limb. The average preoperative tumor volume measured on MRI was 2.93 cm3 [0.11 cm3–25 cm3]. The most common preoperative symptoms were paresthesia (77.1%) and pseudo-Tinel sign (55.7%). Less frequently, pain (50.3%) and hypoesthesia (18.1%) were observed. On the other hand, preoperative neurological motor manifestations remained exceptional (3.3%). The rates of new post-operative motor deficits, paresthesias, and sensory deficits were 4.6%, 10.9% and 8% respectively and were not increased in schwannomas of the collateral nerves of the hand. ConclusionSurgical resection is a safe procedure for peripheral nerve schwannoma treatment with satisfying functional results and an acceptable risk of nerve injury, especially for sensory function. Level of proofD; Multicenter retrospective study.

PET/CT and contrast-enhanced CT imaging findings in benign solitary schwannomas

ObjectivesImaging features of positron emission tomography (PET)/computed tomography (CT) and contrast-enhanced CT and pathological changes in benign solitary schwannoma were retrospectively analyzed, and the factors associated with high uptake of fluorodeoxyglucose (FDG) were examined. MethodsThe PET/CT, contrast-enhanced CT, and pathological results of 58 cases of benign solitary schwannomas confirmed by surgery or biopsy were retrospectively analyzed. The association of each variable with the maximum standardized uptake value (SUVmax) was evaluated. ResultsThe SUVmax of the 58 benign schwannoma cases was 4.1 ± 2.1 (1.5–11.1). When the locations of schwannomas were divided into gastrointestinal system/heart/abdominal and pelvic cavities/thoracic wall (type-1 locations) and other sites (type-2 locations), the schwannoma location was significantly correlated with the SUVmax (r = 0.538, p = 0.000). The SUVmax values were 5.8 ± 2.4 and 3.3 ± 1.5, respectively (p = 0.000). Peritumoral lymphoid cuffs were observed in 7 cases, 4 of which were tumors of gastrointestinal origin, accounting for 80 % of the gastrointestinal schwannomas (4/5). The presence of peritumoral lymphoid cuffs was significantly correlated with the SUVmax (r = 0.456, p = 0.000). The location of the schwannoma was significantly correlated with the presence of peritumoral lymphoid cuffs (r = 0.640, p = 0.000). We found that a peritumoral lymphoid cuff is strongly correlated with the presence of regional lymphadenopathy. Among the 7 cases showing peritumoral lymphoid cuffs, 5 cases had the presence of peritumoral enlarged lymph nodes. The degree of enhancement was significantly correlated with the SUVmax (r = 0.556, p = 0.000). ConclusionsBenign schwannomas originating from the gastrointestinal system/heart/abdominal location and showing the presence of peritumoral lymphoid cuffs or moderate and significant enhancement on contrast-enhanced CT were significantly associated with high FDG uptake. An accurate understanding of the factors associated with high FDG uptake can help reduce the misdiagnosis rate.

Case Report of Schwannomas: Benign Tumour of the Peripheral Nerve Sheath

Schwannomas, also known as neurilemmomas, are benign peripheral nerve sheath tumours arising from the Schwann cells surrounding the nerve. Incidence of peripheral nerve sheath benign tumours occurring in the lower extremities is rare (1–10%). The authors present two cases with solitary schwannomas from the peripheral nerves. In one case, the schwannoma arose from the sural nerve and in the other, from the tibial nerve. They were successfully surgically removed with the aid of a surgical microscope, with no intraoperative or postoperative complications.

Oral Medicine Case Book: An intra-oral solitary Schwannoma of the lower lip, a rare diagnosis

Oral Medicine Case Book: An intra-oral solitary Schwannoma of the lower lip, a rare diagnosis

Schwannom des Magens: seltene Differenzialdiagnose einer akuten oberen gastrointestinalen Blutung

Schwannomas are benign tumors derived from Schwann cells and their typical site of origin is the subcutaneous tissue of the extremities. Gastrointestinal localization of Schwannomas is extremely rare and the stomach is the prevalent site. Gastric schwannomas primarily occur in the gastric submucosa and are usually asymptomatic.We present a rare case of a solitary gastric schwannoma in a 51-year old male, which initially manifested with hematemesis by acute upper gastrointestinal (GI) bleeding. The upper GI-Endoscopy revealed a gastric submucosal tumor, 7 cm in size, located in the proximal corpus and fundus. In the endoscopical Ultrasound (EUS-Examination), the lesion appeared to arise from the fourth proper muscle layer (Muscularis propria). The fourth layer origin and the isoechogenicity, as compared to the normal muscle layer, are endoscopic ultrasonographic characteristics of gastric schwannomas and help in distinguishing them from gastrointestinal tumors (GIST). Because of the unclear histological identity, the patient underwent a "rendezvous" endoscopic-laparoscopic surgical resection of the tumor in toto. The histomorphological features of the lesion and the strong expression of S100 in combination with absence of DOG1 expression indicated the diagnosis of gastric schwannoma. There was no evidence of malignancy. The postoperative course was uncomplicated.This is a very rare manifestation of gastric schwannoma, representing a rare differenzial diagnosis in a case of acute upper GI-Bleeding. Only 14 % of gastric schwanommas are presented with gastrointestinal bleeding, including mainly melena rather than hematemesis. This case is considered to be worthy of presentation owing to the rare and unusual cause of upper GI bleeding implied in it.

Association of Genetic Predisposition With Solitary Schwannoma or Meningioma in Children and Young Adults

Meningiomas and schwannomas are usually sporadic, isolated tumors occurring in adults older than 60 years and are rare in children and young adults. Multiple schwannomas and/or meningiomas are more frequently associated with a tumor suppressor syndrome and, accordingly, trigger genetic testing, whereas solitary tumors do not. Nevertheless, apparently sporadic tumors in young patients may herald a genetic syndrome. To determine the frequency of the known heritable meningioma- or schwannoma-predisposing mutations in children and young adults presenting with a solitary meningioma or schwannoma. Using the database of the Manchester Centre for Genomic Medicine, this cohort study analyzed lymphocyte DNA from young individuals prospectively referred to the clinic for genetic testing between January 1, 1990, and December 31, 2016, on presentation with a single meningioma (n = 42) or schwannoma (n = 135) before age 25 years. Sequencing data were also examined from an additional 39 patients with neurofibromatosis type 2 who were retrospectively identified as having a solitary tumor before age 25 years. Patients with schwannoma were screened for NF2, SMARCB1, and LZTR1 gene mutations, while patients with meningioma were screened for NF2, SMARCB1, SMARCE1, and SUFU. The type of underlying genetic mutation, or lack of a predisposing mutation, was associated with the presenting tumor type and subsequent development of additional tumors or other features of known schwannoma- and meningioma-predisposing syndromes. In 2 cohorts of patients who presented with an isolated meningioma (n = 42; median [range] age, 11 [1-24] years; 22 female) or schwannoma (n = 135; median [range] age, 18 [0.2-24] years; 60 female) before age 25 years, 16 of 42 patients (38%) had a predisposing mutation to meningioma and 27 of 135 patients (20%) to schwannoma, respectively. In the solitary meningioma cohort, 34 of 63 patients (54%) had a constitutional mutation in a known meningioma predisposition gene. Twenty-five of 63 patients (40%) had a constitutional NF2 mutation, and 9 (14%) had a constitutional SMARCE1 mutation. In the cohort of those who developed a solitary schwannoma before age 25 years, 44 of 153 patients (29%) had an identifiable genetic predisposition. Twenty-four patients (55%) with a spinal schwannoma had a constitutional mutation, while only 20 (18%) with a cranial schwannoma had a constitutional predisposition (P < .001). Of 109 cranial schwannomas, 106 (97.2%) were vestibular. Four of 106 people (3.8%) with a cranial schwannoma had an LZTR1 mutation (3 were vestibular schwannomas and 1 was a nonvestibular schwannoma), and 9 (8.5%) had an NF2 mutation. A significant proportion of young people with an apparently sporadic solitary meningioma or schwannoma had a causative predisposition mutation. This finding has important clinical implications because of the risk of additional tumors and the possibility of familial disease. Young patients presenting with a solitary meningioma or schwannoma should be referred for genetic testing.

A mosaic pattern of INI1/SMARCB1 protein expression distinguishes Schwannomatosis and NF2-associated peripheral schwannomas from solitary peripheral schwannomas and NF2-associated vestibular schwannomas.

The INI1/SMARCB1 gene protein product has been implicated in the direct pathogenesis of schwannomas from patients with one form of schwannomatosis [SWNTS1; MIM # 162091] showing a mosaic pattern of loss of protein expression by immunohistochemistry [93% in familial vs. 55% in sporadic cases]. To verify whether such INI1/SMARCB1 mosaic pattern could be extended to all schwannomas arising in the sporadic and familial schwannomatoses [i.e. to SMARCB1-related (SWNTS1) or LZTR1-related (SWNTS2) schwannomatosis or to SMARCB1/LZTR1-negative schwannomatosis] and whether it could be involved in classical NF2 or solitary peripheral schwannomas METHODS: We blindly analysed schwannoma samples obtained from a total of 22 patients including (a) 2 patients (2 males; aged 38 and 55years) affected by non-familial SMARCB1-associated schwannomatosis (SWTNS1); (b) 1 patient (1 female; aged 33years) affected by familial schwannomatosis (SWTNS1/ SMARCB1 germ line mutations); (c) 5 patients (3 males, 2 females; aged 33 to 35years) affected by non-familial (sporadic) LZTR1-associated schwannomatosis (SWNTS2); (d) 3 patients (3 males; aged 35 to 47years) affected by familial schwannomatosis (SWTNS2/ LZTR1 germ line mutations); (e) 2 patients (1 male, 1 female; aged 63 and 49years, respectively) affected by non-familial schwannomatosis (SWTNS, negative for SMARCB1, LZTR1 and NF2 gene mutations); (f) 4 patients (3 males, 1 females; aged 15 to 24years) affected by classical NF2 (NF2: harbouring NF2 germ line mutations; and (g) 5 patients (3 males, 2 females; aged 33 to 68years) who had solitary schwannomas. [follow-up=15-30years; negative for constitutional/somatic mutation analysis for the SMARCB1, LZTR1 and NF2 genes] were (blindly) analyzed. The INI1/SMARCB1 immunostaining pattern was regarded as (1) diffuse positive nuclear staining [= retained expression] or (2) mosaic pattern [mixed positive/negative nuclei = loss of expression in a subset of tumour cells]. All solitary peripheral schwannomas and NF2-associated vestibular schwannomas showed diffuse nuclear INI1/SMARCB1 staining in 97-100% of neoplastic cells; schwannomas obtained from all cases of non-familial and familial schwannomatosis and NF2-associated non-vestibular schwannomas showed a mosaic pattern ranging from 10 to 70% of INI1/SMARCB1-positive expression. We did not record a complete lack of nuclear staining. The present data suggests that (a) mosaic loss of immunohistochemical INI1/SMARCB1 expression, despite the interlesional variability, is a reliable marker of schwannomatosis regardless of the involved gene and it might help in the differential diagnosis of schwannomatosis vs. solitary schwannomas and (b) INI1/SMARCB1 expression is not useful in the differential with mosaic NF2, since NF2-associated peripheral schwannomas show the same immunohistochemical pattern.

Erratum: Clinical features of spinal schwannomas in 65 patients with schwannomatosis compared with 831 with solitary schwannomas and 102 with neurofibromatosis Type 2: a retrospective study at a single institution.

Erratum: Clinical features of spinal schwannomas in 65 patients with schwannomatosis compared with 831 with solitary schwannomas and 102 with neurofibromatosis Type 2: a retrospective study at a single institution.

Sinonasal Schwannoma in a Six-Year-Old: An Unusual Presentation

Schwannomas commonly occur in the head and neck region and extremities, but nasal schwannoma is extremely rare. It accounts for less than 4% of benign solitary schwannomas of the head and neck region. Few cases and very few case series have been reported till date. We report the case of a six-year-old female who presented with mouth breathing of two years with persistent and progressive right nasal obstruction of three months. There was recurrent watery ipsilateral nasal discharge, but no epistaxis, no otologic or throat symptoms, no headaches, facial pain, proptosis or visual loss, no facial hypoesthesia, fever or weight loss. She also had right sided epiphora. She had used topical steroid and decongestant without improvement. Ten months prior to presentation, she had right dacrocystorhinostomy. Examination revealed mucosa mass completely filling the right nasal cavity with an ipsilateral deviation of nasal septum—it was painless with no contact bleeds. Nasal patency was clinically absent bilaterally. Computed tomogram revealed expansile isodense soft tissue mass in the right nasal cavity with heterogeneous enhancement on contrast administration which measured 2.5 cm by 3.7 cm by 5.2 cm. She had an intranasal excision of the tumour and histology revealed Antoni A and B patterns, which is diagnostic of schwannoma. She was fully relieved of symptoms after surgery. Conclusion: Solitary nasal schwannoma is rare especially in childhood. There are various causes of epiphora; definitive investigation of the cause in the index case was not established before dacrocystorhinostomy. Thorough nasal evaluation of epiphora or related ocular symptoms should be sought before definitive procedures.

Schwannoma of the seminal vesicle in a patient with rectal cancer

Introduction: Schwannomas are benign tumors arising from the cells responsible for producing the myelin sheath surrounding peripheral nerve cells. Presentation of case: A patient presented with intermittent bloody stools and diarrhea. Following a work-up, including colonoscopy, computed tomography (CT) scan, and endorectal ultrasound and biopsy, he was found to have a clinical T3N1 rectal adenocarcinoma. The CT scan also showed an incidental mass in the right seminal vesicle that on biopsy was consistent with a benign stromal nodule. After neoadjuvant chemoradiation, a low anterior resection (LAR) and concomitant resection of the right seminal vesicle was performed. Pathologic evaluation of the right seminal vesicle revealed a benign schwannoma. Discussion: This unusual case of a solitary schwannoma of the seminal vesicle in a patient with a locally advanced rectal adenocarcinoma illustrates the difficulty in diagnosing these rare lesions because of their generally asymptomatic nature.

The Primary Large Fourth Ventricular Schwannoma Removed by the Cerebellomedullary Fissure Approach. Case Report and Review of the Literature

The objective of this study was to present a case of a solitary fourth intraventricular schwannoma with a review of the literature, and to analyzing the current theories of its origin and application of trancerebellomedullary fissure approach. The authors presented a primary intraventricle schwannoma occurring in the lateral recess of the fourth ventricle in a 53-year-old female. She presented with severe headache, dysphagia, horizontal nystagmus, ataxia and quadriparesis were detected on initial examination. Imaging studies showed a large mass in the fourth ventricle and a marked hydrocephalus. The tumor was removed by microsurgical dissection using the cerebellomedullary fissure approach at our Institution. Complete removal was achieved and no reccurrence was noted follow-up period of 8 months after surgery. To our knowledge, this is the ninth reported case schwannoma of fourth intraventricule in the literature, which is unrelated to the cranial nerves and cerebellar hemisphere parenchyma, blood vessel or to the dura, is extremely rare. The etiology and natural history of intraventricular schwannomas is not well understood. The presenting clinical, radiological and pathological features of this tumor are summarized. We have discussed the effectiveness of this approach for removal of bulky tumors of the fourth ventricle, the other cases reported in the literature are reviewed and the benefits and potential hazards of trancerebellomedullary fissure (T-CMF) approach. Intraventricular schwannomas are benign tumours that are amenable to complete surgical removal, having a good prognosis without the need of adjuvant therapy.

Schwannoma over submandibular region: A rare presentation

Schawannomas (neuromas, neurilemmomas) are benign tumors originating from Schwann cells or nerve fiber sheet cells. They are solitary, encapsulated tumors usually attached to, or surrounded by, a nerve. Most schwannomas of the hypoglossal nerve originate from the intracranial portion, but they may extend extracranially. Solitary and extracranial schwannomas are extremely rare. The peripheral hypoglossal schwannomas are extremely rare. Treatment of these tumors depends on the extension of the tumor. We present the case of a 44-year-old male with swelling over left submandibular region. Patient was successfully treated surgically.

Benign solitary schwannoma of right ulnar nerve – A case report

Introduction: Benign peripheral nerve schwannomas are uncommon tumours. Extra cranial schwannomas have also been reported from uncommon and unusual sites including breast, pancreas, and gastrointestinal system. Peripheral nerve schwannomas may pose a problem in clinical diagnosis, however an appropriate diagnostic work-up including thorough history and clinical examination, Ultrasonography, magnetic resonance imaging, fine needle aspiration cytology, nerve conduction velocity and electromyography study may all help reaching the correct preoperative diagnosis. The important clinical differential diagnoses include traumatic neuroma, neurfibromas, lipoma, cold abscess and muscle hernia. The definitive treatment of benign peripheral nerve schwannoma is complete enucleation of the tumour mass without damaging the intact nerve fascicles followed by confirmatory histopathological examination. When there is a doubt on histopathology, a positive Immunohistochemical staining with S100 is helpful in confirming a diagnosis of schwannoma. Case presentation: We had 40 years female who had a slow growing swelling over the inner aspect of her right elbow for the last one year; this was followed by pain, tingling and numbness over inner one and half fingers of her right hand for six months. Tinnels sign was positive over the swelling. Her subsequent clinical examination and investigations including a magnetic resonance imaging was suggestive of a benign growth in her right ulnar nerve in the elbow region. Complete enucleation of the swelling was done from the right ulnar nerve in the elbow region and subsequent histopathological examination confirmed it to be a benign cellular schwannoma. Patient recovered successfully after the surgery and paresthesia in the distribution of her right ulnar nerve also improved six weeks after surgery. At her last follow-up six months after surgery, the patient was completely asymptomatic and highly satisfied with the results of surgery. Conclusion: A correct preoperative diagnosis of peripheral nerve schwannomas is possible, and it can be successfully managed with complete enucleation of tumour mass with satisfactory patient outcomes.

Sural nerve schwannoma: a case report

The differential diagnosis for a swelling on the posterior aspect of lower leg is very few. The least of all suspected is a Benign peripheral nerve sheath tumor that too a schwannoma. Though schwannomas can be found in any part of the body especially with a predilection for head and neck, on the contrary they are extremely rare in the extremities especially the lower extremity. Here we present one of the few cases of a solitary schwannoma, confirmed on Histopathology, arising from the sural nerve of the right leg which did not present with any other symptoms even though itself being of a considerable size. The tumor was successfully removed with no postoperative complications and recurrence on follow up.

The First Case of Benign Solitary Schwannoma Arising in the Rectus Abdominis Muscle

We presented a rare case of schwannoma arising from the rectus abdominis muscle in a 26-year-old woman. She had referred to our department with a complaint of painless swelling on the right side of the umbilical region. The mass was about 4 cm in diameter, flat, elastic, and immobile. Ultrasonographic examination revealed a 37×30 mm cystic lesion in the right rectus abdominis muscle and showed a heterogeneous low-echo area within the cyst. Magnetic resonance (MR) imaging examination of the abdomen showed a low-intensity in T1-weighted imaging, and T2-weighted images indicated niveau formation of a high-intensity area and a low-intensity area. With these findings, the patient was scheduled for surgery. Surgical specimen was 3×2.5 cm surface-flat cystic tumor containing bloody fluid, and pathological diagnosis was schwannoma associated with cystic degeneration. This is the first case, to our knowledge, of schwannoma arising in the rectus abdominis muscle.