Schwannoma: Radiologic-Pathologic Correlation

Thenar lumps: a review of differentials

Most soft-tissue lumps in the hand are benign, with ganglions being the commonest, but in the thenar region, solid soft-tissue masses are more common than a ganglion. In this review, we focus on soft-tissue lesions (neoplastic and non-neoplastic) presenting as a palpable lump in this region. A specific diagnosis can often be reached using ultrasonography and/or magnetic resonance imaging. Most of these lesions are managed in local hospitals or primary care, whereas some are referred to specialist centres. This review article will help both general and musculoskeletal radiologists to diagnose and characterise these lesions, provide a guide for further imaging, and provide an insight into imaging features that may need specific investigations such as core biopsy, tertiary referral, and further review at multidisciplinary meetings.

External Oblique Muscle Schwannoma: A Rare Anatomical Presentation

Introduction

Schwannomas or neurilemmomas are rare, benign, and usually solitary lesions that arise from the nerve sheath. In the majority of cases, these tumors involve the extremities, head, neck, and trunk.

Case Presentation

In the present study, a 52-year-old man presented to our surgical department for the evaluation of a symptomatic lump in his left lateral abdominal wall. CT and MRI confirmed the presence of a cystic mass located between the external and internal oblique muscles. Histopathology and immunohistochemistry confirmed it to be benign schwannoma.

Discussion

Schwannomas have rarely been reported in the abdominal wall. To the best of our knowledge, this is the first case of schwannoma located in the left upper abdominal wall and the fifth case of abdominal wall schwannoma reported according to the reviewed medical literature.

Conclusion

Benign schwannoma should be included in the differential diagnosis of cystic and symptomatic lesions of the abdominal wall. The treatment of choice is surgical excision, and recurrence is extremely rare.

[Tumor involving the sciatic nerve: neurinoma or neurofibroma? Can MRI make the difference?]

The sciatic nerve is the terminal branch of the sacral plexus. Sciatalgia is a nerve root pain. In most cases, sciatica originates from degenerative disc disease. Tumor involving the sciatic nerve is extremely rare. We here report the case of a 33-year old patient with nerve tumor detected on MRI performed for drug-resistant sciatica. Tumor involving the sciatic nerve is rare and diagnosis is difficult. MRI data are crucial for establishing an effective surgical approach.

Diagnostic Imaging and Management of Common Intra-articular and Peri-articular Soft Tissue Tumors and Tumorlike Conditions of the Knee

Intra-articular (IA) and peri-articular (PA) tumors of the knee are frequently encountered by orthopaedic surgeons. Nonetheless, due to the possibility of great morbidity and potential mortality, it is important to recognize and differentiate between benign and malignant lesions in a timely manner. Therefore, the purpose of this article is to provide a concise, practical, and updated review of commonly encountered IA and PA tumors including intratendinous gout, synovial chondromatosis, schwannoma, pigmented villonodular synovitis, and synovial sarcoma, and a detailed description of differentiating features to include various imaging modalities.

Diffusion-weighted imaging and diffusion tensor imaging as adjuncts to conventional MRI for the diagnosis and management of peripheral nerve sheath tumors: current perspectives and future directions

Peripheral nerve sheath tumors (PNSTs) account for ~ 5% of soft tissue neoplasms and are responsible for a wide spectrum of morbidities ranging from localized neuropathy to fulminant metastatic spread and death. MR imaging represents the gold standard for identification of these neoplasms, however, current anatomic MR imaging markers do not reliably detect or differentiate benign and malignant lesions, and therefore, biopsy or excision is required for definitive diagnosis. Diffusion-weighted MR imaging (DWI) serves as a useful tool in the evaluation and management of PNSTs by providing functional information regarding the degree of diffusion, while diffusion tensor imaging (DTI) aids in determining the directional information of predominant diffusion and has been shown to be particularly useful for pre-operative planning of these tumors by delineating healthy and pathologic fascicles. The article focuses on these important neurogenic lesions, highlighting the current utility of diffusion MR imaging and future directions including computerized radiomic analysis. KEY POINTS: • Anatomic MRI is moderately accurate in differentiating benign from malignant PNST. • Diffusion tensor imaging facilitates pre-operative planning of PNSTs by depicting neuropathy and tractography. • Radiomics will likely augment current observer-based diagnostic criteria for PNSTs.

Saphenous nerve schwannoma as a cause of vascular claudication - case report and review of the literature

Schwannomas are peripheral nerve tumours that are uncommon. They typical present with a palpable mass, pain or neurological changes. We describe a saphenous nerve schwannoma compressing the superficial femoral artery and causing vascular claudication. We also review the literature.

Brachial plexus schwannoma mimicking cervical lymphadenopathy: A case report with emphasis on imaging features

RATIONALE

Brachial plexus schwannomas are rare benign tumors that are derived from Schwann cells. Because they are rare, and because of the complexity of the anatomy of the neck, these tumors can be a challenge to diagnose for radiologists and clinicians. In the present study, we describe a clinical case of brachial plexus schwannoma detected on ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI), and presenting as a palpable neck mass.

PATIENT CONCERNS

A 49-year-old woman had a palpable mass in the right neck, which had been there for the last 1 year. Metastatic cervical lymphadenopathy was suspected in the primary health clinic; therefore, the patient was referred to our hospital.

DIAGNOSES

The right neck mass was a well-circumscribed oval soft tissue mass on US, CT, and MRI. US-guided core needle biopsy was performed and the mass was proved to be a schwannoma.

INTERVENTIONS

The patient did not undergo surgical excision because the brachial plexus schwannoma was small and there was no accompanying neurological symptom.

OUTCOMES

The patient is being followed up regularly at the outpatient department.

LESSONS

Brachial plexus schwannoma should be considered for a differential diagnosis in patients with a palpable neck mass, and imaging studies play an important role in diagnosing the brachial plexus schwannoma.

Intramasseteric Schwanoma mimicking an isolated cheek mass: Case report and review of literature

INTRODUCTION

Schwannoma is a benign well circumscribed tumor of the nerve sheath and it is mostly localized in the head and neck. Intramasseteric schwannoma represents a very rare entity and a few cases have been described in the literature.

PRESENTATION OF CASE

We present a case of an isolated, asymptomatic and slowly progressive right cheek tumor in a middle aged man. Although multiple investigations, including neck scanner and fine needle aspiration, were done, the diagnosis was obscure and difficult before definite surgical resection. Surgery showed an isolated and well-defined tumor inside the masseter muscle which was completely resected. Histopathologic finding confirmed the diagnosis of schwannoma with the characteristic Antoni A and Antoni B cells.

DISCUSSION

Among benign tumors of the peripheral nerves, schwannoma is a specific type that originates from Schwann cells. It is typically slowly growing, neoplasm that is displacing neural structures without direct invasion. History, physical examination, fine needle aspiration, and magnetic resonance imaging are used as diagnostic modalities, however definitive diagnosis and identification of the affected nerve are often difficult up to the time of surgery.

CONCLUSION

Herby we describe a very rare localization of schwannoma arising from masseter muscle in a 30 year old man who presents with painless neck mass. This rare entity should be considered in the differential diagnosis in any patient presented with cheek mass.

Orbital Frontal Nerve Schwannoma-Distinctive Radiological Features

PURPOSE

To review the radiological findings of frontal nerve schwannoma of the orbit and determine distinguishing imaging features.

DESIGN

Retrospective interventional case series.

METHODS

Setting: Single tertiary institution.

PERIOD

September 1996 to December 2016.

PATIENT POPULATION

Thirteen patients with orbital frontal nerve schwannoma.

INTERVENTION

Patients underwent surgical excision following preoperative imaging.

MAIN OUTCOME MEASURES

Imaging characteristics on computed tomography (CT) and magnetic resonance imaging (MRI).

RESULTS

There were 13 patients with histopathologically proven schwannoma of the frontal nerve. Mean age was 44.4 years and 61.5% were male. The majority (84.6%) of frontal nerve schwannomas extended between the supraorbital notch and superior orbital fissure. The most common shape seen in our patients with frontal nerve schwannoma was a multilobulated "beaded" appearance (46.2%), followed by a dumbbell (30.8%), oval (15.4%), and fusiform (7.7%) shape. On CT imaging, all patients had bony remodeling. Target sign, fascicular sign, and cystic degeneration were seen in 76.9%, 35.8%, and 46.2% of patients, respectively. On radiological-pathologic correlation, the zone of tightly packed cellular solid portion (Antoni A pattern) corresponded to the hypointense area on T2-weighted MRI and the hyperintense area on gadolinium-enhanced T1-weighted MRI.

CONCLUSION

Frontal nerve schwannoma should be considered as a differential diagnosis for any superior orbital mass. Our study describes several radiological findings that would point toward its diagnosis, including its multilobulated beaded or dumbbell shape, as well as additional signs such as the target sign, fascicular sign, and cystic degeneration.

A Case of Schwannoma of the Submandibular Region

Background:

We herein described a rare case of schwannoma of the hypoglossal nerve in the submandibular region with diagnostic imaging and histopathological findings.

Case Report:

A 31-years-old woman has had a palpable firm, rubbery, freely mobile mass in the submandibular region. Of imaging, MR images showed homogeneous isointensity on T1-weighted imaging (T1-WI), heterogeneous hypointensity on T2-WI, heterogeneous hyperintensity on short T1 inversion recovery (STIR), and heterogeneous enhancement on contrast-enhanced T1-WI. A clear capsule was observed on the margin and showed hypointense on T2-WI. Dynamic MRI showed heterogeneous gradual increased enhancement. The uptake of contrast medium was regionally slow. Diagnostic imaging using CT and MRI was suspected of salivary gland tumor or neurogenic tumor. In consideration of imaging diagnosis, a pleomorphic adenoma or a schwannoma was suspected. Final diagnosis was confirmed on the basis of histopathological finding and intraoperative findings.

Conclusion:

1. Histopathologic examination is inevitable, because MR findings are not specific.

2. Schwannomas were said to have specific MRI properties, including specific signs (split-fat sign, fascicular sign, target sign). However, they are not always observed.

3. This case confirmed the differential diagnosis on the basis of the intraoperative finding that the tumor was continuous with the hypoglossal nerve.

Nasal Tip Schwannoma Coexisting With Vestibular Schwannoma

Although a schwannoma can originate from any central or peripheral nerves, schwannomas originating from the nasal tip are extremely rare and only 4 cases have been reported so far in English literature. These 4 cases appeared solely without any other accompanying schwannomas. However, the authors recently treated a patient with a nasal tip schwannoma coexisting with vestibular schwannoma. The nasal tip schwannoma was successfully removed without cosmetic deformity by using an open rhinoplasty approach.

Retrospective Analysis of 20 Patients With Schwannomas: Magnetic Resonance Imaging Characteristics, Pain, and Outcomes Following Excision

A Tinel's sign, a percussion-induced, painful sensation, has been reported as the most useful sign for diagnosing a schwannoma. On magnetic resonance imaging, schwannomas often exhibit a split fat sign and a target sign. The typical treatment for schwannomas is surgical excision; however, excision often results in high rates of neurological deficit. The authors retrospectively reviewed 20 patients who underwent excision of a schwannoma from 2007 to 2015. Twenty patients presented with a split fat sign and 12 patients presented with a Tinel's sign on magnetic resonance imaging. Only 3 patients presented with a target sign on magnetic resonance imaging. The operative approach involved removing the schwannoma, preserving the nearby nerve fascicles, and leaving the epineurium open. Follow-up ranged from 3 to 91 months (average, 29 months). At final follow-up, all patients were pain free. Nineteen patients had normal sensation and full function of their affected limb. One patient developed postoperative posterior interosseous nerve palsy. A Tinel's sign, preoperative pain, and a split fat sign on preoperative magnetic resonance imaging are the clinical symptoms most useful for diagnosing a schwannoma. Schwannomas can be safely removed via intracapsular surgical excision with minimal complications, yielding eradication of preoperative pain, normal sensation, and full function. [Orthopedics. 2017; 40(6):e1036-e1043.].

Siatic nerve: beyond the sacral foramen

Sciatica may result from pathologies affecting the nerve both in its intraspinal and extraspinal course. In daily routine, the vast majority of cases are caused by herniation of the lumbar discs compressing the neural roots. Extraspinal causes of sciatic pain are usually underestimated and the imaging study may be completed after reporting the lumbar MRIs. However, early diagnosis of the exact etiology of sciatica is paramount for both relieving the symptoms and preventing any additional neurologic injury. In this pictorial assay, some relatively rare causes of sciatic neuralgia along the route of the sciatic nerve after leaving the sacral foramen will be displayed.

Extracranial Trigeminal Schwannomas: A Retrospective Analysis

OBJECTIVE

To analyse the clinic-radiological features and treatment outcome of extracranial trigeminal schwannomas.

METHOD

Medical records and radiographs of patients treated, from January 2011 to December 2013, for neurogenic tumors were retrospectively reviewed. Extracranial schwannomas other than those of trigeminal nerve were also excluded. A number of parameters, including the patient's age, gender, site, clinical features, radiographic features, histologic variants and treatment provided as well as any associated complications were recorded and analysed.

RESULT

A total of 5 patients met the inclusion criteria. The patients were males, aged 16-56 years. All the schwannomas appear to originate from the terminal branches of trigeminal nerve.

CONCLUSION

Long standing asymptomatic swelling of cheek should include trigeminal schwannomas as the differential diagnosis. The diagnosis though confirmed by the histologic examination but can also be made on the basis of MRI finding. Neural function can be preserved by meticulous surgery.

Peripheral Nerve Schwannoma: A Review of Varying Clinical Presentations and Imaging Findings

A schwannoma or neurilemmoma is a benign, isolated, noninvasive, and encapsulated tumor originating from Schwann cells of the peripheral nerve sheath. The incidence of a schwannoma occurring in the foot and ankle is rare, with prevalence rate of 1% to 10%. Schwannomas have no sex predilection, and they commonly occur in patients in their fourth decade. Malignant transformation of benign schwannoma is unusual; however, it is important to note that malignant variants of schwannomas do exist and account for about 5% to 10% of all soft tissue sarcomas. We present 3 cases of benign schwannoma in the lower extremity. All 3 patients presented with varying clinical symptoms, including pain, paresthesia, weakness, and a palpable mass. A schwannoma was eventually diagnosed in all 3 patients. We discuss and review the known entities of peripheral nerve schwannoma and describe the clinical and imaging findings and therapeutic strategies for treating and diagnosing peripheral nerve schwannoma.

Radioguided Occult Lesion Localization in Deep Schwannomas of the Peripheral Nerves: Results of a Preliminary Case Series

BACKGROUND

The detection of small deep schwannomas of the peripheral nerves has been increasing since the the use of precise neuroimaging techniques has become more widespread; however, although nonpalpable lesions can be well defined by images, it is often difficult to identify them during the surgical procedure. The authors report seven cases of nonpalpable small deep schwannomas surgically treated after their identification using the radioguided occult lesion localization (ROLL) technique.

METHODS

Seven men, whose ages ranged from 34 to 70 years (mean 52 years), presented with symptomatic nonpalpable peripheral nerve lesions; two cases involved the sciatic nerve, two the femoral nerve, two the radial nerve, and one the tibial nerve. Before the operation, all the patients were studied by ultrasonography and magnetic resonance imaging (MRI); 1 h before the surgery 3-5 MBq of ^99mTc labeled with human albumin macroaggregates was injected into the lesion. A gamma detection probe permitted the preoperative and intraoperative detection of the nonpalpable schwannomas.

CONCLUSIONS

The ROLL technique provides good support for identifying small lesions of the peripheral nerves both preoperatively and intraoperatively. This technique permits the use of minimally invasive approaches performed with local anesthesia, with good cosmetic results and acceptance by the patients.

A diagnostic approach to popliteal fossa masses

There is a myriad of potential mass lesions that occur in the popliteal fossa, which present as palpable masses or are found incidentally on imaging. With a thorough knowledge and understanding of the appearances and locations of these different entities, one can narrow the differential diagnoses in the majority of cases. This will eliminate unnecessary additional investigations and enable a more rapid management. We present a review of frequently encountered and less common entities using an anatomical sieve, with the aim of providing a diagnostic approach to popliteal fossa masses.

High-Resolution Ultrasound of Schwannomas of the Limbs: Analysis of 72 Cases

Schwannomas are common benign tumors that develop in peripheral nerves. High-resolution ultrasound (HRUS) is an effective imaging modality in clinics. The aim of this study was to define the value of HRUS in diagnosing schwannomas that originate from different nerves in limbs. We reviewed the ultrasound and surgical records of 72 pathologically confirmed schwannomas in the limbs of 60 patients. Results revealed that 44 (61.1%) of 72 cases, 44 (75.9%) of 58 cases and 0 (0%) of 14 cases received an overall correct pre-operative diagnosis, a correct pre-operative diagnosis in nerve trunks and a correct pre-operative diagnosis in small branches, respectively. Identification of the nerve of origin of schwannomas through HRUS likely increased confidence in diagnosing these benign tumors.

Recurrent solitary fibrous tumor of lumbar spine with vertebral body involvement: imaging features and differential diagnosis with report of a case

Solitary fibrous tumors (SFTs) of the spine are exceedingly rare tumors of mesenchymal origin. Most spinal SFTs arise from the thoracic spine, followed by cervical spine, and last lumbar spine with only 6 cases reported in literature. SFTs represent a wide range of neoplasms, ranging from benign to malignant. These tumors can develop a late recurrence, even after a decade or more of initial presentation, requiring long-term follow-up. We present a case of recurrent SFT of the lumbar spine with vertebral body involvement, presenting more than a decade after initial resection. It was initially misdiagnosed as a paraganglioma. To the best of our knowledge, there have been only 3 previous cases reporting SFT with vertebral body involvement.

Extracranial schwannoma in the carotid space: A retrospective review of 91 cases

BACKGROUND

Schwannomas of the vagus nerve and cervical sympathetic nerve are rare; hence, only limited information exists regarding their diagnosis and clinical management.

METHODS

We conducted a retrospective review of the clinical features, imaging studies, and treatment results of patients with schwannoma of the vagus nerve and schwannoma of the sympathetic nerve.

RESULTS

Of 91 patients, 91% (n = 83) were preoperatively diagnosed with schwannoma tumors. Using the hyoid bone as an anatomic landmark, the location of the schwannoma of the vagus nerve in the carotid space was significantly different to the location of schwannoma of the sympathetic nerve (p = .003). Although 52 of the 76 patients followed up (68%) had postoperative nerve weaknesses, 13 patients (50%) and 14 patients (53.8%), respectively, fully recovered from schwannoma of the vagus nerve and schwannoma of the sympathetic nerve.

CONCLUSION

In the carotid space, schwannomas of the vagus nerve are usually located below the hyoid bone, whereas schwannomas of the sympathetic nerve more commonly arise from the suprahyoid compartment. Accurate preoperative diagnosis and the intracapsular enucleation surgical approach decreased the incidence of postoperative morbidity. © 2016 Wiley Periodicals, Head Neck 39: 42-47, 2017.

Nerve sheath tumor, benign neurogenic slow-growing solitary neurilemmoma of the left ulnar nerve: A case and review of literature

This paper represent a report of a case with ulnar nerve schwannoma (neurilemmoma), benign neurogenic slow-growing, tumors originating from Schwann cells along the course of a nerve (1) (2) (3). Schwannomas are the most common tumors of the peripheral nerves which occur in the adults (0.8–2%) (5). Usually they progress slowly and so they can remain painless swellings for a few years before other symptoms appear. Most of these lesions could be diagnosed clinically, are mobile in the longitudinal plane along the course of the involved nerve but not in the transverse plane (7). EMG, MRI, and ultrasonography are useful tools in the diagnosis. The definitive treatment of benign peripheral nerve schwannomatosis is complete enucleation of the tumor mass without damaging the intact nerve fascicles followed by confirmatory hystopathological examination (12). We present the case of a 62 years old right hand-dominant female who notice a slow increasing bulge over the inner aspect of her distal volar left forearm superior to the wrist, for a longer period of time not exactly specified; this was tracked and associated by pain, tingling and numbness over inner one and half fingers of her left hand in progress until the presentations. A diagnosis of soft-tissue tumor was presumed clinically. The other investigations were ultrasonography (US), nerve conduction studies (NCSs) such as sensory nerve action potential (SNAP) and compound muscle action potential (CMAP). In this case IRM was suggestive of a benign growth in her left ulnar nerve in the forearm region. Microsurgical techniques were used for ample enucleation of the tumor the distal volar left forearm. Subsequent histopathological examination confirmed the presumed diagnosis of a benign cellular schwannoma. At her last follow-up one month after surgery, the patient was neurological gradually improving sensory and motor function and she is highly satisfied with the results of surgery.

Magnetic Resonance Imaging Features of Schwannoma of the Sinonasal Tract

PURPOSE

The purpose of the study was to explore the characteristic magnetic resonance imaging (MRI) findings of schwannoma of the sinonasal tract.

METHODS

Eighteen patients with histopathologically confirmed sinonasal schwannoma underwent conventional MRI, and 12 had dynamic contrast-enhanced MRI studies synchronously. The morphology feature, signal intensity, enhancement degree, and time intensity curve (TIC) pattern of schwannomas were retrospectively analyzed.

RESULTS

This entity appeared as a well-circumscribed, oval or fusiform soft tissue mass with a mean greatest diameter of 38 mm. Schwannomas exhibited isointense on T1-weighted image in 12 patients and hypointense in 6. On T2-weighted image, the lesions were heterogeneously isointense in 14 patients and hyperintense in 4. The lesions had heterogeneously moderate and marked contrast enhancement in 2 and 16, respectively. The mottled-, island-, and multicyst-like appearance were identified in 3, 4, and 11, respectively. Compared with inverted papilloma and lobular capillary hemangioma, the type I TIC is characteristic of schwannoma.

CONCLUSIONS

A well-circumscribed mass displaying T2 intermediate signal intensity, marked enhancement, and type I TIC, with cystic changes, strongly suggests the diagnosis of sinonasal schwannoma.

Telltale signs of peripheral neurogenic tumors on magnetic resonance imaging

Peripheral nerve sheath tumors are categorized into benign and malignant forms, comprising of neurofibroma and schwannoma in the benign category and malignant peripheral nerve sheath tumors in the malignant category. Magnetic resonance imaging plays an important role in the diagnosis of these lesions. The various imaging features and signs that help to identify and characterize a nerve sheath tumor are, distribution of the tumor along a major nerve, an entering or exiting nerve sign, target sign, a fascicular sign and a split-fat sign.

Brachial plexus tumor simulating an axillary metastasis from breast carcinoma

An ipsilateral axillary mass was detected on pre-operative ultrasound in a 79-year-old woman with newly diagnosed breast carcioma. The mass had sonographic features that were initially thought to represent a lymph node completely replaced by metastatic disease. Though ultrasound-guided axillary fine-needle aspiration was attempted, it could not be performed due to pain. At surgery, the mass was found to be a brachial plexus tumor.

Sonographic Differentiation Between Schwannomas and Neurofibromas in the Musculoskeletal System

OBJECTIVES

The purpose of this study was to determine key features and define a strategy for differentiation between schwannomas and neurofibromas using sonography.

METHODS

This retrospective study was approved by the Institutional Review Board at our hospital, and informed consent was waived. We reviewed sonograms of pathologically proven schwannomas and neurofibromas of the extremities and body wall. On grayscale images, tumors were evaluated on the basis of their size, maximum-to-minimum diameter ratio, shape, contour, margin, location, encapsulation, echogenicity, echo texture, cystic changes, presence of intratumoral calcifications, presence of a target sign, and presence of an entering or exiting nerve. If an entering or exiting nerve was identified, the nerve-tumor position and nerve-tumor transition were characterized. On color Doppler images, the presence and amount of vascularity were evaluated. Student t tests were used for analysis of continuous variables (size, maximum-to-minimum diameter ratio, and age); χ(2) and Fisher exact tests were used for analysis of categorical variables.

RESULTS

A total of 146 pathologically proven tumors, including 115 schwannomas and 31 neurofibromas of the extremities and body wall, were included. The maximum diameter, maximum-to-minimum diameter ratio, contour, cystic portion, nerve-tumor position, nerve-tumor transition, and vascularity were significantly different in schwannomas versus neurofibromas (P < .05), and a lobulated contour, fusiform shape, and hypovascularity of neurofibromas could be helpful for differentiation when a prediction model is considered. The nerve-tumor position, nerve-tumor transition, and maximum-to-minimum diameter ratio were also significantly different between groups (P < .05) and thus could be useful for differentiation of neurogenic tumors.

CONCLUSIONS

Sonographic findings are helpful in differentiating between schwannomas and neurofibromas.

Acute presentation of brachial plexus schwannoma secondary to infarction

Schwannomas of the brachial plexus are rare and typically present as slowly growing masses. We describe a case of a 37-year-old female who presented with acute onset of severe left upper extremity pain. Magnetic resonance imaging (MRI) showed a 2.3 × 2.1 cm peripherally enhancing centrally cystic lesion in the left axilla, along the cords of the left brachial plexus, with significant surrounding edema and enhancement. The mass was surgically removed. Pathology was consistent with a schwannoma with infarction. The pain completely resolved immediately after surgery.

Diagnosis and management of schwannomas originating from the cervical vagus nerve

INTRODUCTION

A schwannoma is a benign, slow growing, encapsulated nerve sheath tumour. Presentation of a schwannoma is a diagnostic and management challenge.

METHODS

Internet searches of PubMed/MEDLINE(®) for all articles listing schwannomas of the vagus nerve in the cervical/neck region (1980-2012) were undertaken to ascertain diagnostic pitfalls. The references of all articles were cross-checked to include all pertinent contributions. Further articles were traced through reference lists.

RESULTS

Schwannomas are solitary, well circumscribed and medial to the carotid sheath. Preoperative diagnoses of schwannomas in the lateral part of the neck can cause confusion with its nerve of origin (ie whether it arises from the vagus nerve or a sympathetic chain). Computed tomography and magnetic resonance imaging reveal valuable information regarding the location and origin of the tumour as well as aiding surgical planning. The diagnosis can be confirmed intraoperatively. Postoperative recovery of neurological function is dependent on the type of surgery. Histopathological studies searching for classical features and immunohistochemical staining for S100 also confirm the diagnosis.

CONCLUSIONS

Schwannomas should be considered in the differential diagnoses of unusual masses in the neck. Preoperative imaging elicits valuable information regarding the location and origin of schwannomas and histopathology confirms the diagnosis.

Symptomatic schwannoma of the abdominal wall: A case report and review of the literature

Schwannoma is a rare, benign tumor that arises from the nerve sheath. This tumor usually involves the extremities, but can also be found in the head and neck, trunk, pelvis, retroperitoneum, mediastinum and gastrointestinal tract. In numerous cases, the tumors are asymptomatic and are identified incidentally on physical examination or imaging. Occasionally, schwannoma is symptomatic due to compression of surrounding large nerves. In the present study, a 57-year-old female presented to the surgical outpatient’s department due to a well-localized parietal pain in the left lower quadrant. The onset of the pain occurred three years prior to presentation, without apparent cause and in the absence of other symptoms. Ultrasound and a computed tomography scan revealed a small solid tumor in the anterior abdominal wall, which was dimensionally stable over time, but was not noted in a preliminary analysis by a radiologist. The lesion was surgically removed using an anterior surgical approach. Histopathology revealed the tumor to be benign schwannoma. The painful symptoms completely disappeared. To the best of our knowledge, this is the third case of an abdominal wall benign schwannoma in the medical literature, and the first symptomatic case.

Giant retroperitoneal ancient schwannoma: Is preoperative biopsy always mandatory?

•

Giant schwannoma should be considered in the differential diagnosis of massive pelviabdominal masses.

•

In the presence of severe symptoms, attempted surgical resection without a preoperative biopsy may be warranted.

•

In such cases, total tumour resection, or at least debulking, will be beneficial.

INTRODUCTION

Schwannoma is the term given to tumours arising from Schwann cells of any nerve sheath. It may arise in the retroperitoneum, where it can attain enormous sizes and cause considerable diagnostic and therapeutic difficulties. A variety of incapacitating symptoms may arise, depending on its size alone and the related contagious organs.

PRESENTATION OF CASE

A 71-year-old female, who was incapacitated by a giant abdominal mass, associated with weight loss, immobility, general weakness and constipation. Radiologically, the presence of a huge pelviabdominal tumour was confirmed. A preoperative tissue diagnosis was entertained but omitted, and we resorted to direct surgical excision instead. During surgery, significant bleeding from the surrounding lumbar vessels was encountered, but it was controlled and the tumour was excised intact. Histopathologically, it showed the histologic features of ancient schwannoma.

DISCUSSION

In the patient presented here, who was rendered immobile by the tumour, total excision or at least debulking seemed appropriate, regardless of any biopsy result.

CONCLUSION

The diagnosis of retroperitoneal schwannoma and its variant “ancient schwannoma” should be considered when a huge pelviabdominal tumour is encountered. Although CT guided biopsy may be helpful in reaching a preoperative diagnosis, this might not change the decision for the need of total tumour excision or at least debulking, in the presence of incapacitating symptoms. With large tumours, the possibility of perioperative exanginating haemorrhage should be remembered and the necessary precautions activated.

Schwannomas of the upper extremity: analysis of 34 cases

BACKGROUND

Schwannomas are the most common benign tumours developing in peripheral nerves. They usually present as a slow-growing mass, sometimes associated with pain and paraesthesia. The aim of this study is to define the correct preoperative diagnosis, to review the surgical treatment employed and to evaluate short- and long-term neurological deficits.

METHODS

Thirty-four patients affected by schwannoma in the upper limbs were treated in the period 1995-2011. In 15 patients the tumour was located on the ulnar nerve, in 8 on the median nerve, in 2 on the radial nerve, in 1 on the anterior interosseous nerve, in 1 on the muscle-cutaneous nerve, and in the remaining 7 on the digital nerves. All patients were surgically treated using a microsurgical approach.

RESULTS

The enucleation of the mass was possible without fascicle lesion in 12 cases. In 22 cases resection of the indissociable fascicles was performed. Postoperative paraesthesia was present in 28 out of 34 treated patients; this clinical sign regressed in a mean period of 12 months in 27 patients.

CONCLUSIONS

When approaching a palpable mass in the upper limbs, the possibility of a peripheral nerve tumour should always be considered. It is important to look for typical signs of schwannomas, such as a positive Tinel sign and peripheral paraesthesia. Imaging assessment with magnetic resonance imaging (MRI) and ultrasonography enables the determination of where the tumour takes its origin and from which nerve. Microsurgical techniques and know-how are recommended in approaching the resection in order to respect as many nerve fibres as possible.

Imaging findings of variable axillary mass and axillary lymphadenopathy

The axilla is a triangular space that contains mesenchymal tissues such as fat, vessels, nerves and lymph nodes, from which various diseases can develop. This article describes axillary masses and axillary lymphadenopathies using imaging findings from techniques such as ultrasonography, mammography, computed tomography and magnetic resonance imaging. Awareness of the characteristic imaging findings of disease entities that cause axillary masses and various axillary lymphadenopathies will help in the accurate diagnosis of axillary lesions.

Schwannoma of the submandibular gland: a case report

Introduction

Schwannoma is a benign, solitary, and slowly progressive encapsulated tumor originating from the sheath of myelinated nerve fibers. Schwannoma of the salivary gland is a particularly rare form of an extracranial neurogenic tumor. Here, we present an unusual case of a schwannoma of the submandibular gland in a 19-year-old man. Total excision of the submandibular gland resulted in complete resolution of symptoms with no cranial nerve deficits. The details of the histopathologic and immunohistochemical features are presented.

Case presentation

A 19-year-old Caucasian man was admitted to our clinic with a painless mass on the right side of his neck that he had had for the past four months. A neck examination revealed a smooth-surfaced, mobile, firm, and painless mass, 6cm in its greatest diameter, on the right side of the submandibular region. Fine-needle aspiration cytology was suggestive of a submandibular gland schwannoma. After the initial evaluation, our patient was prepared for surgical evaluation and resection with a presumptive diagnosis of a neurogenic tumor of the submandibular gland. The final diagnosis of schwannoma was verified by microscopic and immunohistochemical studies. At one-year follow-up of the case, there was no evidence of recurrence.

Conclusions

Schwannoma of the salivary gland is a particularly rare form of an extracranial neurogenic tumor. Our findings indicate good prognosis in an unusual case of a submandibular gland schwannoma in a 19-year-old man treated by surgical excision with no recurrence within 12 months of follow-up.

Role of magnetic resonance imaging in evaluation of cerebellopontine angle schwannomas

The aim of the present study was to evaluate the role of Magnetic Resonance Imaging (MRI) to localize and characterize the MR imaging features of cerebellopontine angle schwannomas and to compare with surgical/histopathological findings. It was a prospective study which included 19 patients, who presented with signs and symptoms s/o any lesion in the CP angle and were referred to the radiology department for MRI. All patients included in the study were subjected to detailed clinical history and physical examination following which MRI was carried out on Philips Gyroscan Achieva 1.5 Tesla unit and the standard protocol consisted of T1WI, T2WI, DWI and FLAIR images in axial, sagittal and coronal planes. Hearing abnormality was the most common presenting complaint in patients with CP angle schwannoma's followed by headache and tinnitus. Vestibulocochlear nerve was the most commonly involved nerve in patients with these lesions followed by involvement of trigeminal nerve. MRI was erroneous in giving provisional diagnosis of schwannoma in one case, which on subsequent surgery and histopathology was found to be a meningioma. The sensitivity of MRI for correctly diagnosing vestibular schwannoma was 100 % and specificity was 92.86 % with a positive predictive value of 94.12 % and accuracy of 96.67 %. MRI is considered as an excellent noninvasive investigation for CP angle schwannoma's. It can identify the site and extension of the lesions as well as the characteristic signal. Apart from diagnosing, MR imaging plays an important role in stratifying patients into appropriate treatment options.

Focal hand lesions: review and radiological approach

Focal hand lesions are commonly encountered in clinical practice and are often benign. Magnetic resonance (MR) imaging is the imaging modality of choice in evaluating these lesions as it can accurately determine the nature of the lesion, enhancement pattern and exact location in relation to surrounding tissues. However, while MR features of various soft tissue lesions in the hand have been well described, it is often still difficult to differentiate between benign and malignant lesions. We review the MR imaging features of a variety of focal hand lesions presenting at our institution and propose a classification into "benign", "intermediate grade" (histologically benign but locally aggressive with potential for recurrence) and frankly "malignant" lesions based on MR findings. This aims to narrow down differential diagnoses and helps in further management of the lesion, preoperative planning and, in cases of primary malignancy, local staging. Teaching Points • Hand lesions are often benign and MR is essential as part of the workup. • MR features of various hand lesions are well described but are often non-specific. • Certain MR features may help for the diagnosis but histological examination is usually required. • We aim to classify hand lesions based on MR features such as margin, enhancement and bony involvement. • Classifying these lesions can help narrow down differential diagnoses and aid management.

Case presentations and review of plexiform schwannoma in the foot

Plexiform schwannoma is a soft tissue tumor that rarely presents in the lower extremity. We have reported on 2 cases of plexiform schwannomas that occurred in the foot and ankle. Owing to the relative obscurity of this condition in the lower extremity, we have also provided an overview of plexiform schwannomas and discussed the differences between this and other suspicious nodular soft tissue masses. The first patient was a 38-year-old female, who had a soft tissue mass located on the lateral aspect of her right foot that became symptomatic. The second patient was an 11-year-old male, who had a symptomatic soft tissue mass on the plantar aspect of his right foot. Both patients underwent surgical excision of the tumor.

Neurilemmoma of median nerve

Neurilemmomas constitute one of the most common tumors of peripheral nerves. Rarer amongst them is their occurrence in median nerve in the region of arm. A sixteen-year-old female presented with painless mass in right arm which was non-tender on palpation with positive Tinel's sign and no motor or sensory deficit in the affected arm. Ultrasound examination revealed an eccentrically arising mass of size 19 × 11 mm along median nerve. MRI study revealed a mass homogenously isointense on T1 weighted images and hyperintense in T2 weighted images placed eccentrically in relation to median nerve in arm. Excisional biopsy under loupe magnification was carried out which revealed the mass to be neurilemmoma. This slowly growing benign tumor of peripheral nerves with an incidence of 5% with 14% involvement of Median nerve can be enucleated from the nerve with little or no damage. In spite of advanced imaging studies the mass cannot be differentiated preoperatively from another peripheral nerve sheath tumor neurofibroma. Both these tumors although bearing some clinical and imaging resemblance carry different intraoperative findings, histopathological features and post-operative results.

Imaging findings of head and neck dermatofibrosarcoma protuberans

BACKGROUND AND PURPOSE

Dermatofibrosarcoma protuberans is a rare, locally aggressive sarcoma of the skin in children and adults, usually involving the trunk and extremities and less commonly the head and neck. Despite clinical reports in the literature on the management of dermatofibrosarcoma protuberans, there are limited articles describing its imaging features.

MATERIALS AND METHODS

We retrospectively reviewed the demographics and imaging findings in all 24 patients with pathologically proven dermatofibrosarcoma protuberans of the head and neck seen at a tertiary cancer center between 2001 and 2010.

RESULTS

Twenty-two of the 24 lesions were nodular and well circumscribed; 19 of the 24 were located on the scalp. On imaging, all 24 lesions involved subcutaneous tissues. The lesions ranged in size from 0.6-9.5 cm (mean, 3.7 cm; standard deviation, 2.3 cm). Twelve lesions involved the soft tissues either at or extending directly to the midline. Thirteen lesions were associated with bulging of the skin surface. Fourteen lesions were imaged with CT and 14 with MR imaging. Whereas variable enhancement patterns were noted on CT and MR imaging, dermatofibrosarcoma protuberans was usually T2-hyperintense and demonstrated marked enhancement. None of the lesions was associated with bone invasion, perineural spread, or nodal/distant metastasis.

CONCLUSIONS

Knowledge of the imaging characteristics of dermatofibrosarcoma protuberans may alert neuroradiologists to include dermatofibrosarcoma protuberans in the differential diagnosis of lesions about the head and neck with similar imaging characteristics.

Schwannoma in the upper limbs

Schwannomas are the commonest tumours of peripheral nerves. Despite the classical description that schwannomas are well encapsulated and can be completely enucleated during excision, a portion of them have fascicular involvement and could not be completely shelled out. A retrospective review for 8 patients was carried out over 10 years. 75% of schwannoma occurred over the distal region of upper limb (at elbow or distal to it). It occurs more in the mixed nerve instead of pure sensory or motor nerve. 50% of patients had mixed nerve involvement. Fascicular involvement was very common in schwannoma (75% of patients). Removal of the tumour with fascicles can cause functional deficit. At present, there is no method (including preoperative MRI) which can predict the occurrence of fascicular involvement; the authors therefore proposed a new system to stratify patients who may benefit from interfascicular nerve grafts. In this group of patients, the authors strongly recommend that the possibility and option of nerve graft should be discussed with patients prior to schwannoma excision, so that nerve grafting could be directly proceeded with patient consent in case there is fascicular involvement of tumour found intraoperatively.

Elastographic and contrast-enhanced ultrasound features of a benign schwannoma of the common fibular nerve

Differential diagnosis of a mass in the popliteal fossa includes a number of pathologies, such as Baker's cyst, extra-articular ganglia cyst, hematoma, proliferation of adipose tissue, aneurysm of the popliteal artery, thrombosed varicose vein, gouty tophi and benign or malignant soft tissue tumors. Schwannoma is the most common benign peripheral nerve tumor. However, only a few authors have so far reported on schwannomas located on the common fibular nerve. The aim of this paper is to present contrast-enhanced ultrasound and ultrasound elastographic features of a rare case of schwannoma of the common fibular nerve as well as imaging features of a schwannoma of the peripheral nerve.