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

Nasal Cavity Schwannoma-A Case Report and Review of the Literature

Schwannomas are rare slow-growing benign tumors arising from Schwann cells lining the nerve sheaths. Head and neck schwannomas account for about one-third of all cases, and only 4% of them arise from the sinonasal tract. Its diagnosis is based on histology and immunohistochemistry. Complete surgical excision is the most recommended treatment option, and endoscopic surgery has been widely performed in recent years. In this study, we presented a case of a 55-year-old female with schwannoma arising from the lateral wall of the nasal cavity, causing epistaxis and rhinorrhea. The patient underwent endoscopic excision with prompt resolution of symptoms. The reported cases of nasal cavity schwannoma were reviewed and summarized for educational purposes.

Sinonasal schwannoma masquerading as an IgG4-related nasal mass

An elderly (8th decade) diabetic patient presented with insidious, painless protrusion of the right eye for 1 month, associated with nasal congestion. Past history included healed serous chorioretinopathy in the right eye (>30 years back) and recently diagnosed (1 year prior) autoimmune IgG4-related pancreatitis for which he was on long-term corticosteroids. On nasal endoscopic examination, a well circumscribed mass was found in the right nasal cavity.Keeping in mind the systemic diagnosis, the sinonasal mass was suspected to be a IgG4-related disease. An endoscopic biopsy was performed and revealed a surprise diagnosis of grade 1 nasal schwannoma.

A Rare Instance of Pterygopalatine Fossa Tumor With Hearing Loss as the Main Complaint

Pterygopalatine schwannomas are rare tumors which usually cause the symptoms of the traffic area by the tumors in the pterygopalatine fossa which is difficult to resection. This paper presents 1 rare case of pterygopalatine fossa tumor with hearing loss as the main complaint treated by total resection through the endoscopic endonasal approach.

An Extensive Unilateral Nasal Mass: Septal Schwannoma-Case Report

Schwannomas are benign peripheral nerve sheath tumours that arise from the Schwann cells of the myelinated nerve and may occur throughout the body. Paranasal schwannomas are uncommon lesions, representing less than 4% of all head and neck schwannomas and nasal septal schwannomas are very rare. Here we report a rare case of sinonasal schwannoma in a 46-year-old male who presented with a history of progressive nasal blockage of 3 years duration. The mass was removed by endoscopic approach without any postoperative complication. The rarity of diagnosis was aided by immune histopathology (IHC) of the tissue to confirm the disease.

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.

Schwannoma of the sinonasal tract: case report with review of the literature

Schwannomas of the sinonasal tract are rare, accounting for <4% of head and neck schwannomas. We report the case of a 61-year-old male who presented with unilateral nasal symptoms. Examination and imaging revealed a unilateral polyp at the level of the middle turbinate, with an initial biopsy suggestive of an inflammatory polyp. Due to the persistence of the patient's symptoms and his polyp despite medical therapy, endoscopic nasal polypectomy was performed. The histology surprisingly showed a schwannoma. No further interventions were carried out, and the patient remains disease-free 6 months postoperatively. A review of the literature comprising 60 cases is included. An optimal clinical approach to the investigation and management of schwannomas of the sinonasal tract is subsequently discussed.

Neurilemmoma of the Nasal Cavity and Paranasal Sinuses

OBJECTIVES

Neurilemmoma in the nasal cavity and paranasal sinuses is very rare. The study aimed to improve the understanding of neurilemmoma in the nasal cavity and paranasal sinuses.

MATERIALS AND METHODS

The clinical data of 10 patients with neurilemmoma in the nasal cavity and paranasal sinuses treated from January 2014 to June 2019 in our hospital were retrospectively studied.

RESULTS

There were 6 females and 4 males patients in our study. The mean age was 49.5 years (range 37-77 years), and the most common clinical symptom was unilateral nasal obstruction. The site of tumor included the nasal cavity, maxillary sinus, ethmoid sinus, and sphenoid sinus. There were 2 cases with malignant neurilemmoma. Nine patients underwent functional endoscopic sinus surgery (FESS); however, 1 patient underwent FESS combined with the lateral rhinotomy for complete resection of the tumor. Two patients with malignant neurilemmoma received postoperative radiotherapy. The mean follow-up was 3.82 years (range 2-7 years). There were no incidences of tumor recurrence during the study period.

CONCLUSIONS

Neurilemmoma in the nasal cavity and paranasal sinuses is a mainly benign tumor. Complete surgical excision by FESS is the only treatment option for neurilemmoma in the nasal cavity and paranasal sinuses; while malignant neurilemmoma needs postoperative radiotherapy.

MRI features of different types of sinonasan rhabdomyosarcomas: a series of eleven cases

OBJECTIVE

To retrospectively analyze magnetic resonance imaging (MRI) features of various pathological subtypes of sinonasal rhabdomyosarcoma (RMS) and explore correlations between imaging features and pathological subtypes.

METHODS

In total, 11 cases with embryonal, alveolar or pleomorphic sinonasal RMSs, confirmed by surgical pathology, were selected. Their characteristics and distinctive imaging features were analysed, and the correlation between pathology and imaging features was explored.

RESULTS

Bone destruction was observed in all 11 cases with RMS. Expansive growth was predominant in three alveolar and three embryonal RMS cases, and creeping growth was predominant in two alveolar, two embryonal and one pleomorphic RMS cases. Signs of residual mucosa were observed in all 11 cases, and 10 cases showed involvement of multiple sinus cavities and orbital cavities. All cases exhibited mild-to-intermediate enhancement.

CONCLUSION

Sinonasal RMSs have the following characteristic MRI features: ethmoid sinuses and middle nasal conchae are the prevalent sites; lesions are mainly of mild enhancement; tumours exhibit signs of residual mucosa, mild-to-intermediate enhancement and frequent orbital involvement; bone invasion and bone destruction are frequently observed; and haematogenous metastasis is not as common as lymphatic metastasis. RMSs of various pathological subtypes were not significantly distinct by imaging.

Encapsulated Sinonasal Schwannoma Mimicking an Antrochoanal Polyp

Extracranial schwannomas are uncommon neoplasms of the sinonasal tract arising from peripheral nerve shealth. Mostly acapsulated on histology, but few cases of encapsulated schwannomas have been reported. Its symptoms are nonspecific and initial clinical diagnosis is frequently missed. We report a 13-year-old boy with a huge, encapsulated sinonasal schwannoma initially thought to be an antrochoanal polyp. Computed tomography scan demonstrated a huge irregularly shaped mildly enhancing isodense mass in the right nasal cavity with lateral extension to the ipsilateral maxillary sinus, superior extension into the ethmoids and frontal sinuses and posteriorly into the nasopharynx. The tumour was completely excised via a lateral rhinotomy and patient is still on follow-up.

Diagnostic usefulness of panoramic imaging of the pterygopalatine fossa: case of a schwannoma causing pterygopalatine fossa expansion

The pterygopalatine fossa is a small area between the posterior wall of the maxillary sinus and the anterior surface of the pterygoid process of the sphenoid bone. The pterygopalatine fossa can be seen clearly on panoramic imaging. We present the case of a 57-year-old man who exhibited right pterygopalatine fossa expansion on panoramic imaging. Computed tomography (CT), magnetic resonance imaging (MRI), and panoramic imaging all showed a tumor at the right pterygopalatine fossa in this patient. CT indicated that the tumor replaced right retromaxillary fat and displaced the posterior wall of the maxillary sinus. On MRI, the tumor showed intermediate signal intensity at the paranasal area on T1-weighted images, and variable intermediate and high signal intensities on fat-suppressed T2-weighted images. It was eventually diagnosed as a schwannoma. Thus, panoramic imaging can be used for disease screening at the posterior border of the maxilla. Our conclusion is based on this report of a patient with a schwannoma at the posterior wall of the maxillary sinus, which panoramic imaging revealed to have pterygopalatine fossa expansion.

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.

Septal Schwannoma of the Nose: A Rare Case

A schwannoma is a benign tumor arising from Schwann cells present in the nerve sheath of myelinated nerves.It is rarely seen in the nose and paranasal sinuses, and it very rarely originates from the nasal septum. A 40-year-old female presented to our outpatient department with a gradual onset, progressive, left nasal obstruction since the last 4 years. On performing a local examination, a soft tissue mass occupying the left nasal cavity was seen. Surgery via the external approach was performed; the mass was found to arise from the nasal septum and was totally excised. Histopathologic examination revealed a schwannoma. Nasal septal schwannoma along with review of the literature is a rare entity. It should be considered in the differential diagnosis of benign tumors of the nasal cavity.

Pediatric Isolated Sinonasal Schwannoma: A New Case Report and Literature Review

Schwannomas of the paranasal sinus are uncommon. Less than 4% of schwannomas involve the nasal cavity and paranasal sinuses, even less in the pediatric age group. A case of schwannoma arising in maxillary sinus in a 2.5-year-old Chinese boy is reported. The basis for discussion of this case is the exceptional rarity of sinonasal schwannoma in pediatric patients.

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.

Role of endoscopic surgery in the management of sinonasal and skull base schwannomas

BACKGROUND

The purpose of this study was to report our experience with the endoscopic management of sinonasal schwannomas, analyzing the advantages, limitations, and outcomes of the technique.

METHODS

A retrospective analysis was carried out on 11 patients treated endoscopically between 2000 and 2014 at a single institution.

RESULTS

Eight patients underwent an exclusive endoscopic endonasal approach, whereas, in 3 patients, an osteoplastic flap was combined because of massive or lateral frontal sinus involvement. The tumor extended into the orbit in 5 cases, and involved the skull base in 5 patients who required a concomitant endoscopic duraplasty. No evidence of disease was observed in 10 patients after a mean follow-up of 90.1 months (range, 14-189 months). One patient was alive with persistence of disease, although asymptomatic.

CONCLUSION

The endoscopic endonasal approach is a valid alternative for the vast majority of sinonasal schwannomas with minimal morbidity for the patient. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2074-E2082, 2016.

Endoscopic removal of giant intranasal schwannoma

Schwannoma is a benign neoplasm originating from schwann cells of the peripheral nerve sheath. Although nearly half of all schwannomas involve the head and neck region, nasal and paranasal sinus presentations are very rare in the literature. We present a case of nasal schwannoma originating from the right nasal cavity. A 59-year-old man presented with complaints of progressive right nasal obstruction and headache. Endoscopic examinations revealed a mass that filled the right middle meatus. At first glance, it was not like polyp tissue. Endoscopic sinus surgery was performed under general anesthesia, and the mass was completely removed.

Improved performance in differentiating benign from malignant sinonasal tumors using diffusion-weighted combined with dynamic contrast-enhanced magnetic resonance imaging

Background:

Differentiating benign from malignant sinonsal lesions is essential for treatment planning as well as determining the patient's prognosis, but the differentiation is often difficult in clinical practice. The study aimed to determine whether the combination of diffusion-weighted (DW) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can improve the performance in differentiating benign from malignant sinonasal tumors.

Methods:

This retrospective study included 197 consecutive patients with sinonasal tumors (116 malignant tumors and 81 benign tumors). All patients underwent both DW and DCE-MRI in a 3-T magnetic resonance scanner. Two different settings of b values (0,700 and 0,1000 s/mm²) and two different strategies of region of interest (ROI) including whole slice (WS) and partial slice (PS) were used to calculate apparent diffusion coefficients (ADCs). A DW parameter with WS ADCs_b0,1000 and two DCE-MRI parameters (time intensity curve [TIC] and time to peak enhancement [Tpeak]) were finally combined to use in differentiating the benign from the malignant tumors in this study.

Results:

The mean ADCs of malignant sinonasal tumors (WS ADCs_b0,1000 = 1.084 × 10⁻³ mm²/s) were significantly lower than those of benign tumors (WS ADCs_b0,1000 = 1.617 × 10⁻³ mm²/s, P < 0.001). The accuracy using WS ADCs_b0,1000 alone was 83.7% in differentiating the benign from the malignant tumors (85.3% sensitivity, 81.2% specificity, 86.4% positive predictive value [PPV], and 79.5% negative predictive value [NPV]). The accuracy using DCE with Tpeak and TIC alone was 72.1% (69.1% sensitivity, 74.1% specificity, 77.5% PPV, and 65.1% NPV). Using DW-MRI parameter was superior than using DCE parameters in differentiation between benign and malignant sinonasal tumors (P < 0.001). The accuracy was 87.3% (90.5% sensitivity, 82.7% specificity, 88.2% PPV, and 85.9% NPV) using DW-MRI combined with DCE-MRI, which was superior than that using DCE-MRI alone or using DW-MRI alone (both P < 0.001) in differentiating the benign from the malignant tumors.

Conclusions:

Diffusion-weighted combined with DCE-MRI can improve imaging performance in differentiating benign from malignant sinonasal tumors, which has the potential to improve diagnostic accuracy and to provide added value in the management for these tumors.

Schwannoma of the Sinonasal Tract and the Pterygopalatine Fossa with or without Intracranial Extension

AIMS

Compared with those in other head and neck regions, schwannomas in the nasal cavity or paranasal sinuses are rare. The aim of this study was to present the experience of the authors in 11 schwannoma cases of the sinonasal tract and pterygopalatine fossa over a decade.

METHODS

A retrospective study from 2003 to 2014.

RESULTS

Three female and 8 male patients from 22 to 61 years of age (mean age 42 years) were admitted. The most common complaints were unilateral nasal congestion. A total of 10 of the patients received surgery, including 6 functional endoscopic sinus surgeries (FESS). The postoperative course was generally uneventful. Among the patients, 10 remained regionally asymptomatic, and there has been no clinical or radiological evidence of recurrence or residual tumor.

CONCLUSION

Surgical treatment is effective for schwannomas of the sinonasal tract and the pterygopalatine fossa with a low recurrence rate. Conducting CT and MRI (particularly fluid-attenuated inversion recovery) before surgery is mandatory. FESS could become the primary treatment of choice.

Atypical presentation of sinonasal cellular schwannoma: a nonsolitary mass with osseous, orbital, and intracranial invasion

Objective Sinonasal cellular schwannoma represents < 4% of head and neck schwannomas. These benign tumors are typically confined to the nasal cavity or ethmoid sinus. We describe an atypical case of sinonasal cellular schwannoma with diffuse paranasal sinus involvement and both intraorbital and intracranial extension.

Results A 62-year-old woman presented with a 6-month history of right orbital proptosis and right-sided headache. Subsequent imaging revealed an invasive paranasal sinus mass extending through the skull base and displacing the right orbit. Preoperative biopsies were not diagnostic but revealed a spindle cell lesion suspicious for malignancy based on lack of encapsulation, infiltration of the sinonasal submucosa, and osseous invasion. The patient underwent open skull base surgery, and pathology confirmed a S100-positive nonencapsulated cellular schwannoma.

Conclusion An atypical case of sinonasal cellular schwannoma with intracranial extension is reported. Its presentation is contrary to the common view that these are isolated solitary lesions of the nasoethmoid region. We suggest that sinonasal cellular schwannoma be considered in the differential diagnosis of a poorly defined invasive paranasal sinus mass, particularly following biopsy.

CT findings of pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts of the neck

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare and recently recognized mesenchymal tumor with intermediate malignant potential, most of which arises in the soft tissue of the extremities with obvious specificity on histopathology. Here, we report a case of CT findings of PHAT arising from the posterior neck as a 3.4 × 4 × 5-cm mass in a 35-year-old woman. Precontrast CT showed an ill-defined, inhomogenous and oval-shaped mass. On contrast-enhanced CT, the mass appeared well defined except for a very small part, most of which showed marked and heterogenous enhancement, with a maximum CT value of 161 HU, which was almost identical to that of the vessels.