Intranasal schwannoma: magnetic resonance and computed tomography appearance

Retroperitoneal cystic schwannoma mimics liquefied hematoma

Schwannomas are nerve sheath tumors that seldom occur in the retroperitoneal region. Herein, we describe an incidentally detected retroperitoneal schwannoma that mimicked liquefied hematoma on computed tomography. A 61-year-old man was admitted to the emergency department with chest pain caused by a fall at a construction site. Chest computed tomography incidentally revealed a retroperitoneal cystic mass measuring 10 cm, in addition to multiple rib fractures and hemopneumothorax. The patient frequently consumed alcohol and had a history of repeated trauma; therefore, we considered the following 2 conditions: retroperitoneal cystic tumor and liquefied hematoma. He underwent complete surgical excision, and a histopathological examination confirmed the mass as a schwannoma. Experience and knowledge regarding the computed tomography findings of retroperitoneal cystic schwannoma are useful for the differential diagnosis of infrequent retroperitoneal tumors.

Retroperitoneal Schwannoma: Two Rare Case Reports

Schwannomas are neuroectodermal tumors that rarely occur in the retroperitoneal space. We report two cases of patients who presented with abdominal pain. Radiological findings revealed a retroperitoneal mass in both cases. Both patients underwent complete surgical excision with an uneventful postoperative course. The histopathological study confirmed the nature of schwannoma. Complete surgical excision remains the gold standard for the management of these tumors. The preoperative diagnosis is usually difficult; however, the definitive diagnosis is made upon histopathological examination.

Schwannoma on the nasal dorsum and tip with sensory changes

Schwannomas, which originate from Schwann cells in the peripheral nervous system, are slowgrowing and uncommon benign tumors. Most schwannomas (90%) occur in isolation, and multiple occurrences are a characteristic feature of neurofibromas. Schwannomas of the nose and nasal tip are particularly unusual. Although a few cases of schwannomas of the sinusoidal tract and nasal septum have been reported, schwannomas arising from the nasal dorsum area and tip are extremely rare. Sensory abnormalities are also a very rare symptom. We excised a schwannoma on the nasal dorsum through direct incision and a schwannoma on the nasal tip through open rhinoplasty. No postoperative complications involving recurrence, hematoma, or infection occurred. The possibility of neurological changes should be considered in cases of an abnormality in the peripheral nervous system. Schwannoma must be kept in mind as a possible cause of neurological changes localized to a specific dermatome, and should always be considered in the differential diagnosis of a mass on the nose.

Schwannoma of the Membranous Nasal Septum: a Clinical Report With Aesthetic Approach

Schwannoma is an uncommon tumor of nerve sheath that arises from any peripheral, cranial, or autonomic nerve. Only 4% of head and neck schwannomas originate from the sinonasal tract, and a finding of a schwannoma in the nasal septum is exceedingly rare. The authors experienced nasal septal schwannoma with the functional and aesthetic consideration of nasal contour. The authors present an open rhinoplasty approach for nasal septal schwannoma which has not been reported in the previous literature yet.

Giant retroperitoneal schwannoma in a 52-year-old man

Schwannoma in the retroperitoneal space is rare, and it is extremely rare in patients with no history of neurofibromatosis. We present a case of giant retroperitoneal schwannoma in a 52-year-old man who did not have neurofibromatosis. Because malignant transformation would be extremely rare in this circumstance, close imaging follow-up could avert the necessity for complete resection. The possibility of schwannoma should be considered when evaluating retroperitoneal tumors with the characteristic findings, even if there is no connection between the tumor and the intervertebral foramina.

Endoscopic Endonasal Approach for the Treatment of Benign Schwannoma of the Sinonasal Tract and Pterygopalatine Fossa

Schwannomas are tumors that rarely involve the sinonasal tract or the pterygopalatine fossa. Three cases of benign schwannomas originating in the nasal cavity, the nasal-ethmoid, and the pterygopalatine fossa are reported. Surgical treatment is considered the treatment of choice to achieve long-term success. In this study, the effectiveness of the endoscopic endonasal approach is outlined for the diagnosis and treatment of these benign tumors.

Sinonasal Schwannoma: A Rare Sinonasal Neoplasm

Neoplasm in sinonasal cavity is dominated by epithelial type. Sinonasal schwannoma is a rare entity represent less than four percent of head and neck schwannoma. Clinically this tumour is commonly misdiagnosed until they are confirmed by histopathological examination. We present a case of schwannoma in sinonasal region with involvement of right side nasal cavity, maxillary sinus and maxillary alveolar process. The tumour was successfully removed by midfacial degloving approach.

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.

Sinonasal Tumors: Computed Tomography and MR Imaging Features

This article describes the computed tomography and MR imaging features of the neoplasms of the sinonasal space. Although a pathologic diagnosis may not always be possible, knowledge of the features may help in narrowing down the differentials and establishing a malignant pathology.

Schwannomas of the sinonasal tract and anterior skull base: a systematic review of 94 cases

BACKGROUND

Schwannomas of the anterior skull base (ASB) and sinonasal tract are extremely rare. These lesions mimic other pathologies such as olfactory groove meningiomas, hemangiopericytomas, and esthesioneuroblastomas. Because of their low incidence, ASB and sinonasal tract schwannomas have not been well characterized. A systematic review of ASB and sinonasal tract schwannomas was conducted to further elucidate the presentation and surgical management of these lesions.

METHODS

A MEDLINE/PubMed search was performed, identifying 71 articles representing 94 cases of ASB and sinonasal schwannomas. Each case was analyzed for demographics, clinical presentation, anatomic location, radiographic features, and surgical treatment.

RESULTS

In 94 patients with ASB and sinonasal schwannomas, 44 (46.8%) were exclusively sinonasal, 30 cases (31.9%) were exclusively intracranial, 12 (12.8%) were primarily intracranial with extension into the paranasal sinuses, and 8 (8.5%) were primarily sinonasal with intracranial extension. Headaches and nasal obstruction were the most common presenting symptoms occurring in 30.9 and 29.8% of cases, respectively. Magnetic resonance imaging typically showed a hyperintense mass on T2-weighted imaging (70%) and hypointense (41%) on T1-weighted imaging. Most patients underwent surgical gross total resection via craniotomy, endoscopic endonasal approach, rhinotomy, or other sinonasal approaches. Recurrence occurred in three cases ranging from 4 months to 13 years. Postoperative complications included cerebral spinal fluid leakage, bacterial meningitis, epidural hematoma, and pneumocranium.

CONCLUSION

ASB and sinonasal schwannomas are rare lesions and should be considered in the differential diagnosis of ASB masses involving the cribriform plate with sinonasal extension. Gross total resection of these lesions should be considered the goal of operative management.

A solitary malignant schwannoma in the choana and nasal septum

Malignant schwannoma is an extremely rare tumor and the risk of malignant schwannoma increases in patients with von Recklinghausen's disease. Recently, we encountered a case of solitary malignant schwannoma in the choana and posterior nasal septum. Malignant schwannoma has not been previously reported in these locations. A 53-year-old man, who was immunologically healthy and showed no abnormal dermatological lesions, presented with a polypoid mass in the right nasal cavity and underwent endoscopic mass excision. The mass originated from the choana and the posterior portion of the right nasal septum. This mass was confirmed as a malignant schwannoma on histological examination and immunohistochemical staining. After endoscopic excision, postoperative adjuvant radiotherapy was administered, and there was no recurrence at 1 year after treatment. This case suggests that a solitary malignant schwannoma should be considered in the differential diagnosis of a mass in the posterior nasal cavity.

Schwannoma of the nose and paranasal sinuses

Sckhwannoma is a benign tumor arising from the Schwann cells of nerve sheath.Through they arise more commonly in the head and neck than other regions, a through search in the liturature including medline revealed only about 47 reported cases of schwannoma in the paranasal sinuses of which the maxillary sinus involvement is more common. We report three cases of schwannoma arising from unusual sites in the paranasal sinuses with different modes of presttation each requiring a specific approach for surgical excision Transnasal endoscopic approach in combination with vonventional approaches is of immense value in the surgical management of these benign lessions of the paranasal sinuses.

CT and MR imaging findings of sinonasal schwannoma: a review of 12 cases

Schwannomas are benign tumors that are rarely found in the sinonasal cavity, and the purpose of this study was to characterize the CT and MR imaging findings of 12 patients with surgically proved sinonasal schwannomas. Assessed features include location, margin, shape, size, internal architecture, pattern and degree of enhancement, and associated bony wall changes. The characteristic CT and MR imaging findings of sinonasal schwannoma include a well-defined soft-tissue mass, most frequently occurring in the nasal cavity and ethmoid sinus with pressure remodeling of the adjacent bony wall. The tumors were isoattenuating on CT and predominantly isointense on both T1- and T2-weighted MR images, compared with the brain stem. Mild contrast enhancement on CT and strong enhancement on MR images were also demonstrated in most of the tumors, and cystic or hemorrhagic changes were noted in 2 cases.

An Asymptomatic Schwannoma of the Nasal Septum: Report of a Unique Case

Schwannomas of the nasal septum are extremely rare, and therefore their diagnosis and treatment can pose certain challenges. We describe the case of an incidentally discovered schwannoma of the nasal septum that was unique in that the lesion was completely asymptomatic. In view of our finding, we believe that routine examinations of both nasal fossae should be considered during routine diagnostic laryngeal flexible endoscopy.

Atypical sinonasal Schwannomas: a difficult diagnostic challenge

OBJECTIVE

Schwannomas are benign tumours arising from Schwann cells of the peripheral nerve sheath. They are relatively frequent in the head and neck region (25-45%) but rarely involve in the sinonasal tract (4%). The authors outline the diagnostic difficulties and the problems in choosing the best surgical approach in two atypical cases of sinonasal Schwannomas.

METHODS

In the first case reported clinical data, sex and age of the patient, nasal endoscopy and angio-MRI led us to suspect an angiofibroma; therefore, we approached the case without a biopsy performing a preoperative selective embolization followed by an endoscopic resection. In the second case, due to initial visual symptoms and to the ethmoid-orbital compartment involvement, we performed a sinonasal endoscopy and collected a biopsy which resulted to be fundamental in the diagnostic assessment. Tumour excision was then obtained throughout an intracranial/endonasal approach.

RESULTS

The two presented cases revealed the presence of cystic Schwannomas. In the first case, diagnosis was made only post-operatively after histological examination. Patients underwent complete surgical excision by means of an endoscopic sinonasal approach, in the second case associated to a left frontal craniotomy. The patients showed no signs of recurrence at a 9 months follow-up.

CONCLUSIONS

Nasal endoscopy was extremely important in making the diagnosis, allowing an accurate assessment of the tumour extension and a biopsy. The diagnosis of sinonasal Schwannomas remains challenging; sometimes, clinical behaviour and modern imaging may be misleading. The diagnostic and therapeutic importance of sinonasal endoscopy is emphasised in the two presented cases.

Facial malignant peripheral nerve sheath tumors

BACKGROUND/PURPOSE

Malignant peripheral nerve sheath tumors (MPNSTs) are rare neoplasms, only sporadically reported involving the maxillo-mandibular region (ten cases with CT or MR data). We present here five additional cases with CT and MR findings along with an extensive review of the literature.

RESULTS

Accurate diagnosis of MPNSTs is difficult because pathological like radiological criteria are often non specific. Radiological features display a large spectrum of abnormalities from a well-delineated heterogeneous appearance simulating benign schwannoma to extensive erosive patterns. Their development along the mandibular nerve, the absence of any target or central dot sign, their strong predominant peripheral enhancement must suggest the diagnosis of MPNSTs while irregular bone destruction or the detection of poorly defined margins with muscular infiltration are the most reliable criteria of malignancy. Unfortunately, MPNSTs also display a considerably varied histology. Careful clinical and radiological correlation should bring pathologists to examining large samples of the lesion to better evaluate the overall organisation of the lesion and detect some evocative criteria often only present in some areas of the sample as the peculiar curlicue or whorled arrangement of the spindle cells or the alternation of densely cellular fascicles with hypocellular, myxoid zones. Focal, limited immunostaining for S-100 protein is one of the most important additional criterion.

CONCLUSION

If accurate early diagnosis often remains difficult, careful correlation of clinical, pathological and radiological data should in most cases suggest a diagnosis of MPNSTs which display a poor prognosis and requires early and adapted treatment.

Description of a neural sheath tumor of the trigeminal nerve: immunohistochemical and electron microscopy study

CONTEXT

Malignant neural sheath tumors of the trigeminal nerve affecting the nasal cavity and the paranasal sinuses are extremely rare. With conventional optical microscopy, their identification is difficult, and it is necessary to confirm them by means of electron microscopy and immunohistochemical techniques.

CASE REPORT

The patient was a 41-year-old woman with a ten-month progressive history of pain followed by painful edema in the left facial region, and with symptoms of bleeding, secretion and nasal obstruction. Studies with imaging methods suggested the presence of an expansive process in the left nasal and paranasal cavities. In the biopsy, the histopathological findings from optical microscopy were suggestive of a tumor of neural origin in the trigeminal nerve. Immunohistochemical and electron microscopy studies confirmed that it was a malignant tumor of the neural sheath of the trigeminal nerve. We describe the clinical, radiological, and histological features of this tumor and review the literature.

Schwannoma of the nasal septum

Schwannomas of the nasal cavity and paranasal sinuses are very rare. We report the case of a 54-year-old woman with a schwannoma arising from the nasal septum. We discuss the clinical presentation, differential diagnosis, imaging characteristics and treatment of this rarely encountered lesion.

Clinical characteristics and treatment outcome for nonvestibular schwannomas of the head and neck

PURPOSE

Studies involving head and neck schwannomas have focused predominantly on involvement of the vestibulocochlear nerve complex (acoustic neuroma) because of the associated morbidity related to lesions involving that region. However, the majority of head and neck schwannomas are not of vestibular nerve origin and may also produce significant morbidity due to involvement of the orbit, skull base, and cranial nerves. The purpose of this study is to examine the presenting signs and symptoms, location, nerve of origin, and outcome after treatment of patients with nonvestibular schwannomas of the head and neck.

MATERIALS AND METHODS

The medical and pathological records of all patients with nonvestibular head and neck schwannomas treated at a single institution between 1979 and 1999 were retrospectively reviewed.

RESULTS

Eighteen (69%) of 26 patients presented with symptoms secondary to mass effect or nerve deficit. The parapharyngeal space was the most common site of tumor origin occurring in 8 patients (31%). The nerve of origin was identified in 16 patients (62%). Twenty-three patients (88%) had complete surgical excision, and 3 patients (12%) had subtotal resection. Postoperative nerve injury occurred in 16 patients (62%) with resolution in 7 patients (44%).

CONCLUSIONS

Nonvestibular head and neck schwannomas occur most commonly in the parapharyngeal space, and presenting signs or symptoms are usually related to mass effect or neural deficit. Complete tumor removal is often achieved, but subtotal or near-total resection may be indicated for patients with extensive skull base, middle ear, or facial nerve involvement. Postoperative morbidity is associated with nerve injury from the surgical approach and/or resection of the involved nerve.

Malignant Peripheral Nerve Sheath Tumor of the Paranasal Sinuses

Malignant peripheral nerve sheath tumors of the nose and paranasal sinuses are extremely uncommon. We report the case of a 65-year-old woman who presented with a rapid emergence of “nasal polyps” that completely obstructed her nasal passages. Six years earlier, she had been assessed elsewhere for nasal polyps. At presentation, the patient exhibited gross polyposis, with lesions protruding from both nostrils. Histology confirmed a diagnosis of a malignant peripheral nerve sheath tumor. This case demonstrates that symptoms of nasal obstruction are not always secondary to simple causes. We discuss the clinical picture of nasal and paranasal malignant peripheral nerve sheath tumor, its pathology, and its treatment.

Sphenoid sinus schwannoma treated by endoscopic excision

Schwannomas, arising from the Schwann cells of the nerve sheath, occur very rarely in the sino-nasal tract and histological diagnosis can, sometimes, be difficult. We describe a case of schwannoma of the sphenoidal sinus occurring in a 71-year-old man, who underwent complete excision of the tumour endoscopically. To our knowledge, this is the third case of sphenoid sinus schwannoma reported in the English literature.