Schwannoma: Radiologic-Pathologic Correlation

Long-term Follow-up with MRI Scans After Enucleation of Peripheral Nerve Schwannomas: Results from a Single-center Case Series

BACKGROUND

Enucleation is a surgical technique to resect peripheral nerve schwannomas. The procedure has a low risk for postoperative deficit, but a small chance for recurrence, because tumor cells may remain inside the pseudocapsule that is left after resection. Magnetic resonance imaging (MRI) scans are frequently performed after surgery to investigate potential residual tumor, but currently there is little information in the literature on the value of follow-up with MRI.

MATERIAL AND METHODS

All patients who underwent enucleation of a peripheral nerve schwannoma between October 2013 and June 2022 were included. Postoperative MRI scans (gadolinium-enhanced) made at different time points after the surgery were re-examined for residual enhancement. Patients with residual enhancement were contacted to inform whether symptoms had recurred.

RESULTS

A total of 75 schwannoma enucleations in 74 patients were included. The first postoperative MRI scan, performed 3 months after the surgery, showed no residual enhancement in 50 patients. In the remaining 24 patients, another MRI scan was made 1 year after the surgery, which still showed a possible remnant in 11 patients. On the third MRI scan, performed 2 years after enucleation, there were 7 suspected cases (9%). None of these patients had clinical symptoms at a mean postoperative follow-up of 5 years.

CONCLUSIONS

Our data show that the value of postoperative MRI scans after enucleation of peripheral nerve schwannomas is limited, because residual enhancement in the beginning can be non-specific and the small percentage of patients, that persistently had a potential remnant, were all asymptomatic.

Low back pain with axillary mass in a perimenopausal woman: A case of schwannomatosis mimicking metastasis

Schwannomatosis is a rare neurocutaneous syndrome characterized by the presence of multiple schwannomas along the peripheral nerves, distinctly excluding the vestibular nerves. It is recognized as the third principal form of neurofibromatosis, alongside neurofibromatosis types 1 and 2. In this report, we discuss the case of a 45-year-old woman who initially sought medical attention for low back pain and swelling in her left axilla. Her magnetic resonance imaging revealed multiple enhancing intradural extramedullary lesions, along with a mass in the right upper thoracic region and another in the left axilla, raising suspicions of metastasis. However, a comprehensive analysis that aligned imaging results with histopathological findings confirmed the diagnosis of schwannomatosis. This case highlights the importance of differentiating between various conditions that can cause multiple intradural extramedullary masses, such as nerve sheath tumors, meningiomas, and metastasis. The presence of multiple schwannomas suggests a diagnosis of either neurofibromatosis type 2 or schwannomatosis, making the distinction between these two conditions critical for appropriate management.

A Rare Case of Sural Schwannoma With Involvement of the Medial Sural Cutaneous Nerve: A Case Report and Literature Review

Schwannomas are benign tumors derived from Schwann cells, typically occurring in the head, neck, and upper extremities, but are less frequent in the lower extremities. They can arise sporadically or from genetic conditions such as neurofibromatosis type 2, associated with NF2 gene mutations. This report details the case of a 57-year-old female with a two-year history of a painless, slowly growing mass in the posterior aspect of the right proximal cruris. Physical examination revealed a 2 cm, elastic-hard, mobile, non-tender mass with a positive Tinel's sign. Ultrasound and magnetic resonance imaging suggested a benign nerve sheath tumor characterized by hypoechoic features. The performed surgery revealed that the tumor involved the medial sural cutaneous nerve. Histologic analysis confirmed the diagnosis of schwannoma, showing typical Antoni A and Antoni B regions. Postoperative recovery was uneventful, with no recurrence or neurological deficits at the two-month follow-up. This case demonstrates an unusual localization of a sural schwannoma and highlights the importance of precise physical examination and imaging to diagnose schwannomas accurately. Clinicians should consider schwannoma as a differential diagnosis in patients presenting with slow-growing palpable masses in the lower extremities.

Cubital tunnel syndrome: anatomy, pathology, and imaging

Cubital tunnel syndrome (CuTS) is the second most common peripheral neuropathy in the upper limb. It occurs due to ulnar nerve compression within the fibro-osseous cubital tunnel at the elbow joint. Although CuTS is typically diagnosed clinically and with electrodiagnostic studies, the importance of imaging in evaluating the condition is growing. Knowing the typical imaging findings of ulnar nerve entrapment is necessary for precise diagnosis and proper treatment. In this article, we focus on the clinical features, workup and complex imaging of the "anatomic" cubital tunnel and relevant pathological entities.

The role of preoperative ultrasound in the management of peripheral nerve injuries

BACKGROUND

Peripheral nerve injury refers to any damage or trauma to the nerves located outside the central nervous system. Ultrasonography is a reliable, cheap, and minimally invasive method in clinical practice to give physicians useful information about nerve injury.

OBJECTIVES

to assess the power of ultrasound in determining the presence, localization, and extent of neural damage in patients with clinical evidence of peripheral nerve lesions before surgery.

METHODS

This cross-sectional study was conducted on 78 patients (56 females and 22 males, aged from 9 to 52 years) who had different pathologies including entrapment, tumoral, post-traumatic, and post-surgical nerve injuries at the Neurosurgery and Physical Medicine, Rheumatology, and Rehabilitation Departments, Tanta University Hospitals. All studied patients had preoperative evaluation; neurological examination, electrodiagnostic studies, and sonographic examinations with linear array transducers (frequencies ranging from 7.5 to 16 MHz).

RESULTS

The most common pathological condition was entrapment neuropathy (39 patients) (50%). Ultrasound complemented the electrodiagnostic studies by determining the site of entrapment manifested by increased mean maximum cross-sectional area of the nerve proximal to the site of entrapment and nerve hypoechogenicity. In post-traumatic and iatrogenic neuropathies (35 patients) (44.9%), the ultrasound finding revealed neuroma in continuity in nine cases (11.5%), complete neurotmesis with stump neuroma in eighteen patients (23.1%), and eight cases (10.3%) showed perineural adhesion. In all cases, the nerve was hypoechoic at the site of injury. The presence of hyperechoic fibrous tissue could indicate perineural adhesion and the necessity for neurolysis. This study also included three (3.8%) cases had schwannoma, and one case (1.3%) had neurofibroma. Ultrasound was used to confirm the diagnosis by determining the tumor's size and vascular supply.

CONCLUSIONS

Ultrasonography is a diagnostic and surgical planning tool that is becoming more and more useful for the management of peripheral nerve injuries. Its high resolution and real-time capability provide safe and cost-effective scans that aid in determining the extent of injuries. For patients with peripheral nerve injuries, ultrasound is advised to be added to the routine clinical and neurophysiological evaluation. It is also advised to use ultrasound as a first-line imaging modality for tumors thought to be of nerve origin.

A case of intrascrotal extratesticular schwannoma

Schwannomas are benign tumors arising from Schwann cells, which compose the myelin sheath covering peripheral nerves. Although schwannomas can develop in various locations throughout the human body, the scrotum is a rare site for development of a schwannoma. Furthermore, to the best of our knowledge, no study to date has focused on the detailed imaging findings of intrascrotal schwannoma.

Facial nerve schwannoma: Case report and brief review of the literature

Schwannomas are rare nerve sheath tumors that can occur throughout the body, and are symptomatic based on location, size, and impingement on adjacent structures. These tumors are often benign lesions and occur sporadically or from genetic conditions such as neurofibromatosis. Schwannomas may arise from peripheral nerves, gastrointestinal nerves, spinal nerve roots and cranial nerves. Facial nerve schwannomas arise from cranial nerve VII, commonly involving the geniculate ganglion, labyrinthine segment, and internal auditory canal. While small lesions are asymptomatic, larger lesions can cause facial nerve paralysis, and facial spasms. Lesions in the internal auditory canal can cause hearing loss, tinnitus, vertigo, and otalgia. High-resolution CT imaging and MRI imaging are useful for distinguishing between other pathologies that arise from the same region. High-resolution CT scans can show bony degeneration of nearby structures such as the labyrinth or ossicles. MRI imaging shows hypo intensity on T1 imaging, and hyperintensity on T2 imaging. On T1 postcontrast, enhancement can be homogenous or heterogeneous with cystic degeneration if the lesion is large. Nodular enhancement is commonly seen on facial nerve schwannomas within the internal auditory canal. Vestibular schwannomas involving CN VIII are more common, and appear similar to facial nerve schwannomas, but can be distinguished apart due to growth in the geniculate ganglion and/or the labyrinthine segment. Management of asymptomatic or mild lesions is typically conservative with follow up imaging, and surgery for larger lesions. Here, we present a case of a facial nerve schwannoma in a 57-year-old woman.

Beyond squamous cell carcinoma: MRI appearance of uncommon anal neoplasms and mimickers

Anal cancer is an uncommon malignancy. In addition to squamous cell carcinoma, there are a variety of other less common malignancies and benign pathologies that may afflict the anal canal, with which abdominal radiologists should be familiar. Abdominal radiologists should be familiar with the imaging features that can help distinguish different rare anal tumors beyond squamous cell carcinoma and that can aid in diagnosis therefore help steer management. This review discusses these uncommon pathologies with a focus on their imaging appearance, management, and prognosis.

Diagnostic and Therapeutic Strategy for Vagal Schwannoma: Case Series and Literature Review

Background and Objectives: Clinical management of vagal schwannoma is a real diagnostic and therapeutic challenge because the medical history and clinical examination are often non-specific and vagal nerve injury following surgical resection still represents an unsolved problem. The aim of this paper is to provide a case series along with a diagnostic and therapeutic algorithm for vagal schwannoma of the head and neck, combining our experience with clinical evidence available in the literature. Materials and Methods: We retrospectively analyzed a series of patients affected by vagal schwannoma who were treated between 2000 and 2020. In addition, a review of the literature on vagal schwannoma management was conducted. Based on the cases described and the literature review, we made a diagnostic and therapeutic algorithm for the management of vagal schwannoma. Results: We were able to identify 10 patients affected by vagal schwannoma and treated between 2000 and 2020. All patients presented with a painless, mobile, slow-growing lateral neck mass with onset varying from a few months to years. The preoperative diagnostic workup included ultrasound (US) in nine cases, computed tomography (CT) with contrast in six patients and magnetic resonance imaging (MRI) of the neck in seven cases. All patients included in this study were surgically treated. Conclusions: Vagal schwannoma management represents a true challenge for clinicians and surgery is currently the most effective therapeutic strategy. A multidisciplinary approach through the collaboration of otolaryngologist with other specialists is desirable to develop a tailored treatment plan for the patient.

Ultrasound and MR imaging of peripheral nerve tumors: the state of the art

Peripheral nerve sheath tumors are a heterogeneous subgroup of soft tissue tumors that either arise from a peripheral nerve or show nerve sheath differentiation. On imaging, direct continuity with a neural structure or location along a typical nerve distribution represents the most important signs to suggest the diagnosis. Ultrasound and magnetic resonance imaging are the best modalities to evaluate these lesions. First, it is necessary to differentiate between a true tumor and a non-neoplastic nerve condition such as a neuroma, peripheral nerve ganglion, intraneural venous malformation, lipomatosis of nerve, or nerve focal hypertrophy. Then, with a combination of clinical features, conventional and advanced imaging appearances, it is usually possible to characterize neurogenic tumors confidently. This article reviews the features of benign and malignant peripheral nerve sheath tumors, including the rare and recently described tumor types. Furthermore, other malignant neoplasms of peripheral nerves as well as non-neoplastic conditions than can mimick neurogenic tumor are herein discussed.

Primary Soft-Tissue Lymphomas: MRI Features Help Discriminate From Other Soft-Tissue Tumors

OBJECTIVES

MRI presentation of extra-nodal soft-tissue lymphomas (STLs) is scarcely reported and lacks of comparison with other soft-tissue tumors (STTs) including sarcomas (STS). Yet, suggesting this diagnosis on MRI would considerably reduce diagnostic intervals. Our aim was to investigate if conventional MRI could discriminate STLs from other STTs.

METHODS

MRIs of STL patients were compared with those of patients addressed to a sarcoma reference center for the diagnosis of a STT. MRI characteristics depicting the tumor (size, signal, habitats, shape, surrounding tissues) were reported. Uni- and multivariate associations with STL diagnosis were evaluated in the entire cohort, and in the subgroups of benign and malignant STTs patients. Diagnostic performances of MRI features combinations were tested.

RESULTS

We included 39 patients with STLs (median age: 69 years) and 368 patients with other STTs (122 benign STTs and 246 STS; median age: 58 years). Six MRI features were independent predictors of STL compared to all other STTs: intermediate SI on T1-WI, homogeneous enhancement (without necrotic areas), no blood signal, no fibrotic signal, no peritumoral enhancement and lack of abnormal intra- and peritumoral vasculature (p-value range: <0.0001-0.0163). Their simultaneous presence had a sensitivity of 0.88 (0.71-0.96) and a specificity of 0.88 (0.84-0.91). Other relevant MRI features were: no fat signal to discriminate against STS (p = 0.0409), the infiltrative growth pattern and the vessel and nerve encasement to discriminate against benign STTs (p = 0.0016 and 0.0011, respectively).

CONCLUSION

Our research demonstrates that conventional MRI can help discriminating STLs from other STTs. Indeed, radiologists can help suggesting the possible diagnosis of STL, which could speed-up the subsequent proper histopathological analysis in light of MRI findings.

Magnetic resonance imaging features and clinical course of malignant melanotic nerve sheath tumors: single institution experience over two decades

OBJECTIVE

To evaluate MR features and clinical course of malignant melanotic nerve sheath tumor (MMNST), previously known as melanotic schwannoma and considered indolent and rarely metastasizing.

MATERIALS AND METHODS

This IRB-approved retrospective study searched 31 patients (20 male: 11 female, mean age 48; range 15-76) with histologically confirmed MMNST in a single tertiary cancer center over 22 years. Pre-treatment MR was available in 12 patients and evaluated by two radiologists in consensus regarding lesion location, size, morphology, signal characteristics, contrast enhancement, local invasion, and presence of classic signs of peripheral nerve sheath tumors. Clinical outcomes, including local recurrence, metastasis, and survival, were examined in 12 patients for whom follow-up was available.

RESULTS

The spine was the most frequent site (13/31) among all identified cases. In 12 cases with MR, lesions were well-circumscribed in 11/12 cases, with a mean size of 4.5 cm (2.3-13.0 cm). Ten of 12 cases showed T1 hyperintensity. In 5/9 spinal MRI, tumor involved multiple levels. All lesions showed contrast enhancement, and local bone invasion in > 50%. A dumb-bell shape was common to all spinal lesions. Classical signs of nerve sheath tumors were uncommon. Among 12 patients with a mean follow-up of 4.8 years (range 1.3-10.2 years), six were disease-free, while two had recurrence or metastases, and four had died of metastases.

CONCLUSION

MMNST usually presents as a T1 hyperintense enhancing dumb-bell shaped mass in the spine. Multi-level involvement and bone invasion are common. MMNST is clinically aggressive with high rates of metastases and death.

Imaging palpable tumors in pediatrics: Part 2

Palpable tumors in children are a common reason for consulting a radiologist. The origin of these lesions varies widely, and although they are common, classic radiology books do not cover some of them. This series of two articles aims to review the clinical and radiological characteristics of a selection of palpable tumors in children that radiologists need to be familiar with.

Cervical vagal schwannoma, a rare differential of a neck swelling: A case report

Cervical vagal schwannoma is a rare clinical entity that requires a different clinical approach than other neck swellings. Magnetic resonance imaging is the preferred initial diagnostic test. Complications may arise due to vagal stimulation in unsuspecting open biopsies. Surgical excision with perioperative vagal monitoring is recommended for the treatment of vagal schwannomas.

Schwannoma Arising in Nasopharynx: A Case Report and Literature Review

Schwannoma in paranasal sinus has been known as a rare tumor in this origin. This study reports on primary schwannoma arising in the nasopharynx, which is an uncommon location. A 36-year-old female presented with nasal obstruction for one month. Physical examination revealed a nasopharyngeal mass totally occluding bilateral posterior choanae and extended downward to the oropharynx. Magnetic resonance image showed heterogeneous enhancing mass at the nasopharynx extending inferiorly to the oropharynx. The tumor was excised via endoscopic combined trans-nasal/trans-oral approach under general anesthesia. The pathologic diagnosis was consistent with schwannoma. The tumor was successfully excised with en-block resection and the patient was discharged the next day after the operation, without any postoperative complications. There was no tumor recurrence at 12-months follow-up. Schwannoma primarily arising in the nasopharynx is uncommon. Minimally-invasive surgery via the endoscopic approach can be applied for tumor removal with fewer complications and reduced risk of morbidity.

The Varied Presentations of Sinonasal Region Schwannomas: Apropos of Four Cases

Schwannomas of the sinonasal compartment are rare benign neoplasms of peripheral nerve sheath origin and constitute ~ 4% of all head and neck schwannomas. The presentation may simulate a range of benign and intermediate grade pathologies. Management involves surgical excision via open or endoscopic approach. To describe the clinico-epidemiological characteristics and surgical outcomes in sinonasal region schwannoma patients operated at our institute. The study is a descriptive case series of patients with sinonasal region schwannomas treated at our institution. A retrospective search of electronic database of the Department of ENT and Head and Neck Surgeries and Department of Pathology was conducted from January 2013 to January 2019. The various demographic and clinical details of the patients were extracted. A total of four patients operated for sinonasal region schwannoma were identified. The involved sites were nasal dorsum, nasal cavity, pterygopalatine fossa and infratemporal fossa. The mild, non-specific symptoms resulted in patients ignoring their symptoms for a while initially and presenting late. The nasal dorsum lesion was revealed as a surprise during open rhinoplasty for correction of nasal deformity. Complete excision was achieved in all the cases and no recurrence has been noticed during the follow up (varying from 6 months to 6 years) till date. The diverse clinical manifestations and approaches to the treatment of schwannomas in this specific region are discussed. The surgical excision is the standard of care in dealing with these neoplasms. This series highlights the rarity of this pathology in the sinonasal area, diagnostic surprises and the decision making to choose the correct surgical approach for complete excision. Once excised completely, recurrence is not expected.

Pathergy of a Medial Heel Schwannoma

Schwannomas are benign soft-tissue tumors derived from Schwann cells of the peripheral nervous system. They typically appear on the head, neck, or trunk, and are often asymptomatic or present with mild tenderness to palpation and numbness due to nerve compression. A 17-year-old male was referred to our dermatology clinic for evaluation and treatment of an asymptomatic, pink, flesh-colored subcutaneous nodule on the medial right heel. A biopsy was performed to rule out malignancy, with the pathology report consistent with the diagnosis of schwannoma. Following the biopsy, the patient developed a persistent, non-healing red-violaceous ulcerative plaque at the biopsy site, which persisted following additional electrodessication and silver nitrate application. Repeat biopsy showed persistent schwannoma and notably the absence of a pyogenic granuloma. The persistent ulceration following the initial biopsy is consistent with the phenomenon known as pathergy, which refers to exaggerated tissue reactivity in response to trauma. The patient eventually required surgical excision and a keystone flap for definitive treatment of the lesion. Although rare, we have demonstrated that pathergy can occur during surgical procedures on suspected schwannomas. Physicians should be aware of this possible complication so that they can provide anticipatory guidance for patients undergoing surgical procedures on undiagnosed cutaneous neoplasms for which a schwannoma is in the differential diagnosis.

Juxtaneural ganglia arising from the hip joint: focus on magnetic resonance imaging findings and clinical manifestations

OBJECTIVE

To present cases of juxtaneural ganglia arising from the hip with a discussion of the magnetic resonance imaging (MRI) findings, presenting symptoms, and possible treatment option.

MATERIALS AND METHODS

Two radiologists performed a consensus review of MRI scans obtained between January 2013 and March 2021 to identify patients with juxtaneural ganglia around the hip. A total of 11 patients with 11 juxtaneural ganglia were identified. Medical records and MRI findings were retrospectively reviewed.

RESULTS

Eight patients had lesions involving the sciatic nerve, and three patients had lesions involving the obturator nerve. Sciatic ganglia arose from a paralabral cyst in the posteroinferior quadrant and continued through a narrow channel running along the posterior acetabulum, showing increased diameter in the sciatic foramen and intrapelvic portion. Obturator ganglia showed a J- or reverse J-shape on the coronal imaging plane and extended from a paralabral cyst in the anteroinferior quadrant via the obturator canal. Nine patients (9/11, 81.8%) had symptoms resembling those of lumbosacral radiculopathy. Four patients underwent arthroscopic surgery, and one patient underwent ultrasound-guided aspiration, all of whom showed partial improvement. Spontaneous decrease in the extent of the ganglion was observed in three patients (3/11, 27.3%).

CONCLUSION

This article describes rare cases of juxtaneural ganglia arising from the hip joint and involving the sciatic and obturator nerves. The lesions share similar MRI findings, and each type of cyst (sciatic or obturator ganglia) involves a specific labral quadrant.

Orbital schwannoma management: a case report, literature review, and potential paradigm shift

PURPOSE

To present a case of orbital schwannoma and assess the literature on treatment modalities.

METHODS

A MEDLINE literature search for cases of orbital schwannomas was performed using the PubMed search tool using the search terms "orbital schwannoma" and "orbital neurilemmoma." Papers were included if they were peer-reviewed, published in English, discussed management, and included the search terms. Each article was rated using the scale developed by the British Centre for Evidence-Based Medicine. In addition, we present a case report of an orbital schwannoma.

RESULTS

A total of 428 articles were found. 102 met the criteria for inclusion. Only two articles met Level 1 evidence and 16 were important to the clinical care process. We report a case of a biopsy-proven orbital schwannoma managed conservatively with observation over a 4-year period due to risk of cosmetic disfigurement with tumor removal. There has been no change in tumor size and no associated complications during follow up.

CONCLUSIONS

There is a paucity of data on the natural history of orbital schwannomas. Based on our review of the literature, we recommend observation for asymptomatic or minimally symptomatic orbital schwannomas with minimal growth over an extended period of time. For rapidly growing tumors or large tumors affecting key structures causing visual loss, diplopia, aesthetic disfigurement, or patient discomfort, a more aggressive approach may be necessary.

Unusual presentation of lateral sural cutaneous nerve schwannoma: An exceptional case report

Introduction

Schwannoma is the most common benign nerve sheath tumor. Peripheral nerves of the lower extremity are rarely involved and usually asymptomatic.

Case presentation

We report the case of a misleading clinical presentation of lateral sural cutaneous nerve schwannoma.

Discussion

To the best of our knowledge, no case has been reported about the location of schwannoma in the lateral sural cutaneous nerve. MRI and anatomopathologic assessment, after microscopic enucleation, are required to confirm diagnosis.

Conclusion

Care must be taken to not miss a schwannoma of lateral sural cutaneous nerve by meticulous clinical examination and appropriate imaging using MRI in unexplained L5 sciatica.

•

Schwannoma is the most common benign nerve sheath tumor

•

Peripheral nerves of the lower extremity are rarely involved and usually asymptomatic

•

MRI shows isointense or decreased signal relative to the skeletal muscle on T1-weighted images and heterogeneously increased signal intensity on T2-weighted images

•

Microscopic enucleation is treatment of choice

Challenging Management of Plexiform Schwannoma and Plexiform Neurofibroma

ABSTRACT

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

The first experience of ultrasound-guided percutaneous microwave ablation for extracranial schwannoma of the cervical vagus nerve in carotid space and treatment response evaluation with contrast-enhanced imaging

Schwannoma is a benign tumor that originates from Schwann cells in the nerve sheathing of cranial, other peripheral, or autonomic nerves. Patients often present with painless mass as the chief complaint. The main symptoms of this tumor are related to its size and specific nerve origin. At present, the pretreatment diagnosis is mainly made by ultrasound, CT, MR, or biopsy, and the main treatment is surgical resection. We reported a new treatment method for cervical schwannoma in a 65-year-old woman with a history of non-small cell lung cancer (NSCLC). When the patient's neck mass was initially found with hoarseness and severe cough, it was considered as cervical lymph node metastasis of lung cancer due to her medical history. And she was diagnosed with schwannoma by core-needle biopsy after chemotherapy failed and the tumor shrank after the radiotherapy with no improvement of the clinical symptoms. After considering the physical condition, the patients were treated in our department for minimal invasiveness treatment. The patient was definitively diagnosed with cervical vagus schwannoma and was treated with ultrasound-guided microwave ablation of schwannoma under general anesthesia with systematic evaluation and improved preoperative examination. Her condition was stable, and the symptoms of severe cough disappeared after anesthesia resuscitation and the ablation. The tumor continued to shrink after the operation with no recurrence of cough symptoms. Ultrasound-guided percutaneous microwave ablation (MWA) for cervical vagus schwannomas might be a minimally invasive, effective, and relatively safe alternative to conventional treatment for those patients with severe symptoms.

Schwannoma: A Rare Etiology of Pancoast Syndrome

Musculoskeletal disorders represent a major public health problem and they are frequently managed in primary care centers. Shoulder pain is a frequent musculoskeletal complaint and it can result from intrinsic disorders of the shoulder or referred pain. We present the case of a 24-year-old woman who presented to the family medicine clinic complaining of left shoulder pain for three months duration. The pain was not associated with numbness or weakness. There was no history of preceding trauma. The initial diagnosis was supraspinatus tendinosis. The patient was prescribed oral analgesics and was advised to undergo multiple physiotherapy sessions. Later, the patient presented to the clinic again and reported she did not have any improvement in her symptoms. The patient was referred to the orthopedic clinic for further evaluation and management. The patient underwent a frontal radiograph of the chest which demonstrated a well-defined opacity located in the apex of the left lung. A computed tomography scan of the chest demonstrated the presence of erosion to the vertebral body raising the suspicion for a neurogenic tumor as was later supported by magnetic resonance imaging. The patient underwent video-assisted thoracotomy with brachial plexus exploration. Complete resection of the tumor was achieved with no complications. The present case highlights those common musculoskeletal complaints, such as shoulder pain, which could indicate underlying non-orthopedic pathology.

Hypervascular vestibular schwannoma: A case report and review of the literature

Vestibular schwannomas, also known as acoustic neuromas, are benign tumors that arise from Schwann cells near the transition from glial cells to Schwann cells. While most vestibular schwannomas are hypovascular tumors, a small percentage constitute the hemorrhagic and/or hypervascular vestibular schwannomas (HVS) subtype. We describe a case of a 36-year-old female who presented with nausea, vomiting, and an acute decrease in vision in her right eye. Computed tomography of the head demonstrated a hemorrhagic lesion in the right hemisphere with evidence of ventricular effacement. Follow-up magnetic resonance imaging revealed a mass in the right cerebellopontine angle that was hypointense on T1-weighted imaging and mild hyperintense heterogeneous signal on T2-weighted imaging, suggestive of a hemorrhagic vestibular schwannoma. It is important for radiologists to recognize the unique clinical and radiological features of HVS in the initial diagnostic assessment of cerebellopontine angle tumors and to distinguish it from common (hypovascular) vestibular schwannomas and other related pathologies. A preoperative diagnosis of HVS allows clinicians to become familiar with the unique characteristics of the tumor and to devise a feasible operative strategy prior to surgical resection.

Serendipitous Discovery of a Benign Obturator Nerve Schwannoma: Case report with a brief clinical review

Schwannomas are typically benign tumours of the peripheral nerves. However, they seldom arise from the obturator nerve. We report a case of an uncommon swelling (2.5 × 3.5 cm) in a 65-year-old male cadaver, found during a routine dissection session for first Bachelor of Medicine and Surgery students in the Department of Anatomy, Kasturba Medical College, Manipal, India, in 2019. It was seen originating from the left obturator nerve in the pelvis at the level of the sacral promontory. Histopathological investigation revealed a schwannoma. The hypocellular tumour was arranged in a sweeping fascicle pattern with patches of myxoid degeneration. Obturator schwannomas, though rare, can exist in cadavers, as seen in the present case. Hence, it should be considered as a differential diagnosis for clinical cases of pelvic masses and eliminated only after thorough radiological examination. Knowledge about the existence of such schwannomas is therefore essential.

Retrospective analysis of schwannoma in the oral and maxillofacial region: clinicopathological characteristics and specific pathology of ancient change

Schwannomas are benign tumours that originate from the Schwann cells of the nerve. Despite the frequency of their occurrence in the head and neck, data relating to their clinicopathological features in the region are limited. This study reviews the clinicopathological characteristics and specific pathology of ancient (degenerative) change in 40 cases in the oral and maxillofacial region. Medical records were reviewed of the 40 cases treated at Tokyo Medical and Dental University Hospital Faculty of Dentistry between 2000 and 2020. The most frequently involved site was the tongue, and the average tumour size was 13.2 mm. Degenerative changes were observed in eight cases. All tumours were completely excised through biopsy or local excision, and no recurrence was observed on clinical follow up. Statistical analyses revealed significant associations (p < 0.05) between ancient change and tumour size, and between ancient change and the apparent diffusion coefficient (ADC) value derived from diffusion-weighted magnetic resonance imaging (MRI). Analysis suggests that schwannoma progresses over a long period and subsequently undergoes secondary ancient changes. Pathological events such as cystic formation and haemorrhage that are associated with ancient changes, cause hypocellularity and lead to high ADC values. These values may indicate ancient change and should be considered when distinguishing schwannoma from other lesions.

Evaluation of schwannoma using the 3D-SPACE sequence: comparison with the 3D-CISS sequence in 3T-MRI

Background/aim

The purpose of this study is to compare the diagnostic accuracy and interobserver reliability of the T2-weighted 3D-SPACE (three-dimensional sampling perfection with application-optimized contrasts by using different flip angle evolutions) sequence in comparison with T2-weighted 3D-CISS (three-dimensional constructive interference in steady state) sequences for diagnosis of schwannomas.

Materials and methods

Forty patients with cerebellopontine angle (CPA), internal acoustic canal (IAC), and cochlear schwannoma who had undergone magnetic resonance imaging (MRI) using the 3D-CISS and 3D-SPACE sequences were identified. The sequences were retrospectively evaluated by two radiologists for the qualitative analyses, which were subsequently compared using the Mann–Whitney U test. Following this, kappa values were used for interobserver agreement. P < 0.05 was considered to be of statistical significance.

Results

The interobserver agreement was found to be excellent between the two observers for the interpretation of all qualitative analyses for both sequences (kappa value > 0.8). The 3D-SPACE sequences demonstrated significantly better qualitative scores and fewer artifacts compared with the 3D-CISS sequences (p < 0.05).

Conclusion

Our results demonstrate that 3D-SPACE is superior to 3D-CISS in the imaging process of the schwannoma in terms of image quality, description of the relationship between the lesion and cranial nerve, signal differentiation between lesion and cistern, and signal differentiation between the lesion and adjacent brain.

Schwannoma of the abdominal wall: updated literature review

Background

Schwannoma is a benign tumor arising from Schwann cells of the peripheral nerves. It is often asymptomatic and can develop in the retroperitoneum, mediastinum, head and neck region, and upper and lower extremities. Schwannoma of the abdominal wall is extremely rare, but differential diagnosis with malignant neoplasms is important to reduce the risk of undertreatment.

Methods

A narrative review of abdominal wall schwannoma was performed using PubMed, EMBASE, and Web of Science database and the search terms “schwannoma”, “neurinoma”, “neurilemmoma”, “soft tissue tumors”, “neurogenic tumor”, “rectus abdominis mass”, “abdominal wall”. In addition, the hospital charts were reviewed to report the personal experience.

Results

Only 9 single case-reports of benign schwannoma of the abdominal wall were found in the English medical literature over the past decade. None of the patients received preoperative biopsy and all were resected with clear margins. In addition to the literature review, we report the case of a 58-year-old man referred for a palpable mass in the left upper abdominal quadrant. Ultrasonography and magnetic resonance imaging revealed a solid and well-encapsulated mass inside the left rectus abdominis muscle. A core biopsy of the lesion provided the diagnosis of cellular schwannoma and this was confirmed by histopathologic examination of the surgical specimen.

Conclusions

Benign schwannoma of the abdominal wall is extremely rare. Percutaneous core needle biopsy is important for the differential diagnosis with more common and biologically more aggressive malignancies, such as desmoid tumors and sarcomas, and may be relevant for planning the most appropriate management.

Comparison of pathological, radiological, and prognostic features between cellular schwannoma and non-cellular schwannoma

PURPOSE

To investigate the differences of pathological, radiological, and prognostic features between cellular schwannoma (CS) and non-cellular schwannoma (NCS).

METHODS

CT and MRI images of 24 patients with CSs and 30 patients with NCSs were reviewed retrospectively. Clinico-pathological characteristics of CSs and NCSs and tumor radiological features including location, shape, size, border, cystic-solid components, hemorrhage, calcification, bone remodeling, pattern of CT/MRI precontrast scan, degree of enhancement, target sign, and tumor vessels were recorded. Statistical analyses were performed with Chi square or Fisher's exact test, independent sample t test, and logistic regression analysis to compare the differences between CSs and NCSs.

RESULTS

Four CSs showed mitotic activity, which was not found in the NCS group (P = 0.034). The CS group showed higher MIB-1 index than that in the NCS group (P = 0.002). Two patients with CS presented with tumor recurrence. Compared to NCSs, CSs were often located in spinal area (P = 0.028) and irregular (P = 0.013) with larger size (P = 0.005). Target sign, a common finding in NCSs (7/22, 31.8 %), was not seen in CSs (P = 0.014). The tumor vessels were only seen in CS group (4/22, 18.2 %; P = 0.027). Regression analysis revealed that location (P = 0.048) and size (P = 0.012) were independent indicators in differentiating CSs from NCSs.

CONCLUSIONS

CS is a rare subtype of schwannoma with some significant radiological features including a predilection for the spinal area, irregular shape, large tumor size, absent target sign, tumor vessels, and potential risk of recurrence. Location and size of the schwannomas were the most useful indicators in differentiating CSs from NCSs.

Brachial plexus schwannoma mimicking advanced breast carcinoma

BACKGROUND

Schwannoma is an extremely rare benign tumour of the peripheral nervous system; its association with breast cancer is sporadic, and its association with the brachial plexus is extremely rare.

CASE DESCRIPTION

The authors report a case of a patient with breast cancer associated with nodulation in the left supraclavicular fossa, and due to the clinical and radiological features, it was considered metastatic lymph node disease. The patient underwent neoadjuvant chemotherapy, with partial response of the breast. Surgical treatment included resection of the supraclavicular nodule, which was found to be a supraclavicular fossa schwannoma. The correct diagnosis, influences the radiotherapeutic planning. The unusual presentation led to diagnostic confusion in the present case, a fact that changed the breast treatment.

CONCLUSION

The best of our knowledge it is the third description of brachial plexus schwannoma associated with breast cancer and the first with a synchronous association. The knowledge of this pathology and its potential to alter treatment justify the reporting of the present case.

Primary Tumors of the Sacrum: Imaging Findings

The diagnosis of sacral neoplasms is often delayed because they tend to remain clinically silent for a long time. Imaging is useful at all stages of managing sacral bone tumors: from the detection of the neoplasm to the long-term follow-up. Radiographs are recommended as the modality of choice to begin the imaging workup of a patient with known or suspected sacral pathology. More sensitive examinations such as computerized tomography (CT), magnetic resonance (MRI), or scintigraphy are often necessary. The morphological features of the lesions on CT and MRI help to orientate the diagnosis. Although some imaging characteristics are helpful to limit the differential diagnosis, an imaging-guided biopsy is often ultimately required to establish a specific diagnosis. Imaging is of paramount importance even in the long-term follow-up in order to assess any residual tumor when surgical resection is incomplete, to assess the efficacy of adjuvant chemotherapy and radiotherapy, and to detect recurrence.

A clinicopathological study of peripheral schwannomas

Aim and objective

Schwannomas are benign neoplasms of neural origin with sporadic or syndromic occurence. They are commonly seen in cranial nerves. Peripheral schwannomas occur rarely and may have unique presentations. The aim of this study is to evaluate the clinico-pathological characteristics of peripheral schwannomas.

Methods

A retrospective cross sectional study of peripheral schwannomas excluding head neck region was conducted. The study group consisted of 18 cases which were recorded over a period of seven years. The corresponding data were collected from the archives of the Department of Pathology.

Results

Male to female ratio was 1:1. The average age of the cases was 47 years. The most common site was the upper limbs (55.55%) followed by lower limbs, chest and penis. The lesions mostly presented as painless swellings (62%). Histopathological examination revealed classic features of schwannoma. Secondary changes included cystic degeneration, foam cells, epitheloid cells, hyalinization, microcystic change and collection of plasma cells. All cases were confirmed by positive S100 staining.

Conclusion

Peripheral schwannomas may be missed due to its rarity and atypical presentations. Both clinicians and pathologists should be aware of this common entity at unusual sites for the proper management of the patients. Surgery is usually the treatment of choice.

Nerve Sheath Myxoma in the Lower Extremity: A Rare Case with Description of Magnetic Resonance Imaging and Sonographic Findings

BACKGROUND This report is of a nerve sheath myxoma presenting as a slow-growing mass in the back of the left ankle of a 36-year-old man that was investigated by ultrasound and magnetic resonance imaging (MRI) before the diagnosis was confirmed by histopathology. CASE REPORT We report a nerve sheath myxoma of the ankle in a 36-year-old man. The palpable abnormality was falsely assumed to be a ganglion cyst prior to advanced imaging. Magnetic resonance imaging demonstrated a lobular mass with high T2 and intermediate T1 signal as well as moderate enhancement. T2 sequences also demonstrated distinctive internal septae. These internal septae were also noted on sonographic evaluation prior to biopsy. The patient was treated with surgical excision, and pathologic analysis showed myxoid nodules with loose arrangements of spindled cells separated by fibrous septae. S-100 protein and glial fibrillary acidic protein positivity by immunohistochemistry staining was demonstrated. Follow-up imaging at 12 months showed no evidence of tumor recurrence. CONCLUSIONS This case highlights that while nerve sheath myxomas are rare tumors, they should be considered in cases of cutaneous soft-tissue masses with myxoid imaging features. Ultrasound and magnetic resonance imaging features of thin internal septae may be present and correspond well with the unique histopathological characteristics of these lesions. This report shows the importance of imaging of peripheral soft-tissue masses, including ultrasound and MRI, which can identify localized and benign features and the solid, cystic, and myxoid areas, which were characteristic in this case of benign nerve sheath myxoma.

Solitary Fibrous tumor of the lumbar spine mimicking a sequestered disc fragment

Solitary fibrous tumor in the lumbar spine is a rare pathology with non-specific radiographic features, sometimes resulting in misdiagnosis. Our patient was a 41-year old female who presented with low back pain and bilateral leg pain. Initial MRI showed a lesion misdiagnosed for a sequestered disc at the mid L4-5 level, which was subsequently characterized appropriately and treated surgically, with resolution of symptoms. Pathologic diagnosis was most consistent with a solitary fibrous tumor due to STAT 6 and CD 34 reactivity. Long-term follow up is recommended in these patients to monitor tumor recurrence and evidence of metastasis.

Schwannomas of Uncommon Peripheral Locations: Analysis of Imaging Findings of 21 Cases

BACKGROUND

Schwannomas are benign slow-growing tumors most often associated with the cranial nerves. Schwannomas often originate from the eighth cranial nerve. They may also originate from the peripheral nervous system of the neck and extremities. However extracranial peripheral schwannomas are considered a rare entity.

OBJECTIVES

The knowledge of rare localizations and typical imaging findings will lead to a successfulradiological diagnosis. Therefore, in this study, we present the clinical findings and MRI characteristics of schwannomas with a rare localization involving the peripheral, lower and upper extremity and intramuscular regions.

MATERIALS AND METHODS

The hospital database was screened for patients with an extracranial soft tissue mass. Twenty-one cases of schwannomas were found in rare localization. We analyzed the MR images of these patients retrospectively. The MR images were evaluated in terms of tumor location, signal intensity, and enhancement pattern. The histological examination of all the patients confirmed the diagnosis of schwannoma.

RESULTS

In 21 patients, the schwannomas were peripheral, localized to upper (n = 6) and lower extremities (n = 11). The remaining four patients had intramuscular schwannomas. The patients diagnosed with intramuscular schwannomas had schwannomas in sternocleidomastoid, gastrocnemius, triceps muscle and lateral wall of the abdomen. The average long-axis diameter of the tumor was 27.7 mm and the average short-axis diameter was 16.4 mm. The contrast pattern was diffused in eight tumors and peripheral in 13.

CONCLUSION

In this study, we present clinical findings and MRI characteristics of schwannomas with a rare localization involving the peripheral, lower and upper extremity and intramuscular regions.

Cranial nerve schwannoma - A pictorial essay

Schwannomas are peripheral nerve sheath tumours arising from cranial, spinal or peripheral nerves. Most of the schwannomas are benign with the rare possibility of malignant transformation. Cranial nerve schwannomas can be seen along the course of any cranial nerve in the intracranial region or head and neck location. Although a majority are solitary sporadic lesions, multiple schwannomas can be seen in syndromes like neurofibromatosis type 2 and rarely in type 1. Since intracranial schwannomas are slow-growing, clinical presentation varies between no symptoms to cranial nerve palsy. Most of the times, the symptoms are due to mass effect over the adjacent structures, foraminal widening, compression of other cranial nerves, denervation injury or hydrocephalus. Familiarity with the course of the cranial nerves, imaging appearances and clinical presentation of schwannomas helps in accurate diagnosis and possible differential diagnosis, especially in uncommon clinical and radiological appearances. In this pictorial review, we illustrate relevant anatomy of cranial nerves, imaging features of schwannomas of most of the cranial nerves, clinical presentation and differential diagnosis.

A rare case of giant retroperitoneal neurilemmoma

Neurilemmoma, also known as schwannoma or neurinoma, is a tumor that originates from neural sheath Schwann cells. Giant neurilemmomas derived from the retroperitoneum have rarely been reported. We herein describe a woman with a giant retroperitoneal neurilemmoma that was initially incorrectly diagnosed as an inflammatory abdominal mass. The tumor extended from the patient's hypogastrium to her pelvic cavity and measured 20 × 15 × 10 cm. The tumor was excised via laparotomy and diagnosed as a retroperitoneal neurilemmoma through histological and immunohistochemical examination. Although rare, particularly in the giant form, neurilemmoma should be considered as an important differential diagnosis in patients with a retroperitoneal tumor or inflammatory abdominal mass. Complete excision should be considered for the potential cure of giant retroperitoneal neurilemmomas.

Sacral tumours and their mimics: pictorial review and diagnostic strategy

Sacral tumours encompass an extensive range of differential diagnosis. The clinical presentation is often non-specific, including neurological deficits and low back pain. Accurate diagnosis of sacral lesions is challenging and requires a comprehensive imaging strategy and robust knowledge on the imaging characteristics of different pathological processes. This review will provide an updated overview of the computed tomography (CT), magnetic resonance imaging (MRI), and integrated positron-emission tomography (PET)-CT features of some common and rare sacral tumours and their mimics. Several clinical scenarios with specific diagnostic considerations and treatment implications will be described.

Oversized primary intrapulmonary schwannoma: A case report and a review of the literature

BACKGROUND

Schwannomas, also known as neurilemommas, are benign, well-circumscribed encapsulated peripheral nerve sheath tumors with rather indolent evolution. Made up of cells closely related to normal myelinating Schwann cells, these neoplasms may arise from the peripheral nervous system as well as from spinal or cranial nerves. They are mostly found in the base of the skull, neck, chest wall, posterior mediastinum, posterior spinal roots, cerebellopontine angle, retroperitoneum, and flexor surfaces of the extremities. The incidence rate of spinal schwannoma is 0.3-0.5/100,000 cases per year with an average age of 50 at diagnosis. We report a case of intrapulmonary schwannoma, adding a review of the literature.

CASE DESCRIPTION

A 20-year-old female patient with no significant medical history, presented with pleuritic chest pain, shortness of breath, right upper limb weakness, and numbness. A computed tomography of the chest and magnetic resonance imaging showed a 7.2 × 10.5 × 8.3 cm mass in the posterior segment of the right upper lobe, arising from the right T5-6 neural foramen; a concurrent 16 mm thick right pleural effusion was also noticed yet without evidence of nodular enhancement. The findings suggested the presence of a neurofibroma or a schwannoma. Complete resection of the tumor was achieved through posterolateral thoracotomy; the ensuing histopathological and immunohistochemical examinations confirmed the presence of a schwannoma.

CONCLUSION

We believe this rare case of pulmonary invasive schwannoma illustrates the complex dynamics of this extremely rare entity; in this particular case, complete surgical excision proved to be crucial in terms of subacute management and local tumor control, at least at short and middle term. The patient is currently asymptomatic (6 months postsurgery) and remains on follow-up.

Historadiological Correlation of Cerebellopontine Angle Tumors: Series of 122 Cases

Cerebellopontine angle (CPA) tumours, are diverse pathologically with regard to the site of tumour origin and displacement of the neurovascular structures. In general CPA tumours are divided into acoustic and non-acoustic tumours. The aim of the present study was to see the spectrum of lesions at cerebellopontine angle and their historadiological correlation. A retrospective analysis of 122 cases of CPA tumors diagnosed in the Department of Pathology, IHBAS was done from January 2004 to August 2019. There were 56 males and 66 females in the age group of 8-68 years. Clinical history ranged from 10 days to 5 years. Clinical symptoms included hearing deficit, visual loss, facial nerve dysfunction, nausea, vomiting, headache, seizures, unsteadiness and disequilibrium. Historadiological correlation was found in 112 cases (91%).In our series of CPA tumors, nonacoustic tumors were more frequent than in previous studies. We found that presence of intrameatal fraction is not exclusive only for schwannomas. There can be a rare occurrence of medullobastoma/small round cell tumor in CP angle. The final pathological verification can at times give unexpected results. Immunohistochemistry did not have a significant role in diagnosis of cerebellopontine angle tumors.

Prevalence and associations of incidental nonvenous duplex findings discovered during lower extremity venous imaging

OBJECTIVE

Venous duplex imaging defines venous pathology (VP). Unexpected clinically relevant findings are also found but rarely mentioned in the literature. This study aims to define the prevalence of ancillary findings (nonvenous duplex) by study type and venous outcome and subgroup associations with primary study indication and risk factors.

METHODS

Our vascular laboratory database was queried for lower extremity venous duplex studies with comments regarding ancillary findings and associated patient demographics, primary study indication, associated conditions, and venous study outcome.

RESULTS

There were 52,215 venous studies performed, 48,425 to evaluate for venous occlusion (acute/chronic) and 3790 for venous reflux. Of these studies, 15,810 found VP and 36,405 found no venous disease. There were 875 studies with venous disease that had ancillary duplex findings (5.5%) noted as 559 (3.5%) with prominent lymph node(s) (LN), 179 (1.1%) Baker's cyst (BC), 44 (0.3%) hematoma/mass (HM), 31 (0.2%) arterial aneurysm, and 16 (0.1%) arterial occlusion. There were 3130 studies free of VP with ancillary findings (8.6%) noted as 2258 (6.2%) prominent LN(s), 626 (1.7%) BC, 156 (0.4%) HM, 37 (0.1%) arterial aneurysm, and 22 (0.06%) arterial occlusion. The overall prevalence of ancillary findings was 8.62%. Analysis demonstrated statistically more ancillary findings in venous occlusion (odds ratio [OR], 1.25) studies, which was the largest group at 13 to 1. Studies free of venous disease had more ancillary findings (P < .001) with an OR of 1.88 and similar results were noted for LN(s), BC, and hematoma. Studies with VP favored a finding of aneurysm (OR, 0.52). Subgroup analyses demonstrated that those with prominent LN(s) were statistically older and male and BC statistically older in those with coexistent venous disease. BC subgroup analysis showed that studies free of venous disease were 2.5 times more likely to report pain as the primary study indication (P < .0001). In general, within ancillary subgroups, leg symptoms were statistically more prominent on the side with ancillary pathology and free of venous disease.

CONCLUSIONS

Ancillary findings are not uncommon and are more common in studies found free of VP. The most common are LNs, BC and HM and, within subgroups, significant leg symptoms favors the presence of ancillary findings without coexisting venous disease. Ancillary findings should be an integral part of a quality report.

MR neurography of the brachial plexus in adult and pediatric age groups: evolution, recent advances, and future directions

Introduction: MR neurography (MRN) of the brachial plexus has emerged in recent years as a safe and accurate modality for the identification of brachial plexopathies in pediatric and adult populations. While clinical differentiation of brachial plexopathy from cervical spine-related radiculopathy or nerve injury has long relied upon nonspecific physical exam and electrodiagnostic testing modalities, MRN now permits detailed interrogation of peripheral nerve anatomy and pathology, as well as assessment of surrounding soft tissues and musculature, thereby facilitating accurate diagnosis. The reader will learn about the current state of brachial plexus MRN, including recent advances and future directions, and gain knowledge about the adult and pediatric brachial plexopathies that can be characterized using these techniques.Areas Covered: The review details recent developments in brachial plexus MRN, including increasing availability of 3.0-T MR scanners at both private and academic diagnostic imaging centers, as well as the advent of multiple new vascular and fat signal suppression techniques. A literature search of PubMed and SCOPUS was used as the principal source of information gathered for this review.Expert Opinion: Refinement of fat-suppression, 3D techniques and diffusion MR imaging modalities has improved the accuracy of MRN, rendering it as a useful adjunct to clinical findings during the evaluation of suspected brachial plexus lesions.

Intramuscular peripheral nerve sheath tumors: schwannoma, ancient schwannoma, and neurofibroma

PURPOSE

To analyze the prevalence of classic magnetic resonance imaging (MRI) findings of intramuscular peripheral nerve sheath tumors (PNSTs), including schwannoma, ancient schwannoma, and neurofibroma.

METHOD

Thirty pathologically confirmed benign intramuscular PNSTs (24 schwannomas, 3 ancient schwannomas, and 3 neurofibromas) were retrospectively reviewed. Classic MRI findings of PNSTs including split fat sign, fascicular sign, target sign, entering and exiting nerve, and thin hyperintense rim were assessed for each intramuscular PNST. Denervation change of the affected muscle was also assessed. In ancient schwannoma and neurofibroma, the signal intensity (SI) and enhancement pattern were analyzed.

RESULTS

All intramuscular schwannomas revealed two more classic MRI findings. Eight of the 24 intramuscular schwannomas revealed affected muscle denervation change. All intramuscular ancient schwannomas showed only split fat sign. All intramuscular ancient schwannomas showed denervation change of the associated muscle. All intramuscular neurofibroma showed split fat sign and one case with target sign was detected. Ancient schwannomas were isointense SI on T1-weighted image (T1WI) and one case had hyperintense foci. They showed heterogeneously hyperintense SI on T2-weighted image (T2WI) with heterogeneous enhancement. Neurofibromas were isointense SI (2/3) and slight hyperintense SI (1/3) on T1WI and heterogeneously hyperintense SI on T2WI with heterogeneous enhancement. One ancient schwannoma showed conglomerated calcifications.

CONCLUSIONS

Intramuscular schwannomas were easily diagnosed based on MRI. In the case of intramuscular ancient schwannoma and neurofibroma with only split fat sign among the classic MRI findings, they might be distinguished from other intramuscular soft tissue tumors based on muscle denervation change or typical crescent split fat sign.

Abdominal wall sonography: a pictorial review

The anterior abdominal wall, which is composed of three layers (skin and adipose tissues; the myofascial layer; and the deep layer, consisting of the transversalis fascia, preperitoneal fat, and the parietal peritoneum), has many functions: containment, support and protection for the intraperitoneal contents, and involvement in movement and breathing. While hernias are often encountered and well reviewed in the literature, the other abdominal wall pathologies are less commonly described. In this pictorial review, we briefly discuss the normal anatomy of the anterior abdominal wall, describe the normal ultrasonographic anatomy, and present a wide range of pathologic abnormalities beyond hernias. Sonography emerges as the diagnostic imaging of first choice for assessing abdominal wall disorders, thus representing a valuable tool for ensuring appropriate management and limiting functional impairment.

Extraprostatic Uptake of 18F-Fluciclovine: Differentiation of Nonprostatic Neoplasms From Metastatic Prostate Cancer

OBJECTIVE. Fluciclovine is a synthetic radiolabeled amino acid analog used for imaging of biochemical recurrent prostate cancer. Uptake of fluciclovine is mediated by several amino acid transporters, including alanine-serine-cysteine transporter 2 and large neutral amino acid transporters, which are known to be overexpressed in other malignancies. CONCLUSION. Knowledge of the common patterns of prostate cancer recurrence, in addition to what other neoplasms can show uptake, is critical for accurate study interpretation.