Magnetic Resonance Imaging Features of Schwannoma of the Sinonasal Tract

Endoscopic Management of Ethmoidal Schwannoma: A Case Report

Schwannomas of sinonasal origin are rare tumours with an incidence as low as 4% and may present with a wide range of clinical features. Due to non-specific endoscopic and radiological findings, diagnosis becomes difficult. We present a case of an ethmoidal schwannoma with nasal and nasopharyngeal extension in an elderly female patient who had a slow course of the long-standing disease. Her main complaints were nasal obstruction, nasal discharge, mouth breathing, snoring and recurrent nasal bleed. Nasal endoscopy showed a pale, firm, polypoidal mass with dilated vessels on the surface which bled on probing. It was a non-enhancing sinonasal mass with scalloping of adjacent paranasal sinuses and erosion of posterior nasal septum on contrast-enhanced computed tomography. Endoscopic excision of the mass was done in toto and histopathology report confirmed it as schwannoma. Long standing sinonasal masses especially in the elderly age group with an indolent medical history should arise suspicion of benign neoplasm especially schwannomas due to their high rate of incidence amongst benign sinonasal neoplasms.

ACR Appropriateness Criteria® Sinonasal Disease: 2021 Update

This article presents guidelines for initial imaging utilization in patients presenting with sinonasal disease, including acute rhinosinusitis without and with suspected orbital and intracranial complications, chronic rhinosinusitis, suspected invasive fungal sinusitis, suspected sinonasal mass, and suspected cerebrospinal fluid leak. CT and MRI are the primary imaging modalities used to evaluate patients with sinonasal disease. Given its detailed depiction of bony anatomy, CT can accurately demonstrate the presence of sinonasal disease, bony erosions, and anatomic variants, and is essential for surgical planning. Given its superior soft tissue contrast, MRI can accurately identify clinically suspected intracranial and intraorbital complications, delineate soft tissue extension of tumor and distinguish mass from obstructed secretions.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Small Cell Neuroendocrine Carcinoma of Paranasal Sinuses: Radiologic Features in 14 Cases

The purpose of this study was to explore the characteristic computed tomography (CT) and magnetic resonance (MR) features of small cell neuroendocrine carcinoma (SNEC) of paranasal sinuses.

Sinonasal synovial sarcoma: evaluation of the role of radiological and clinicopathological features in diagnosis

AIM

To explore the value of radiological and clinicopathological features in the diagnosis of sinonasal synovial sarcomas (SS).

MATERIALS AND METHODS

Six patients with sinonasal SS were studied retrospectively using computed tomography (CT; n=6) and magnetic resonance imaging (MRI; n=4). The radiological and clinicopathological findings in this series were reviewed.

RESULTS

Three lesions were located, in both the nasal cavity, and the paranasal sinuses; one was located in the nasal cavity and nasopharynx, and the remaining two were located restrictively within the nasal cavity. An aggressive nature (invasion of adjacent structure) was found in four cases. At CT, lesions were found with isodensity with calcification mainly in the peripheral areas. Bony changes were visible in all cases. Five cases showed marked heterogeneous enhancement, and three cases contained necrotic or cystic areas. At MRI, haemorrhage was observed in three cases. All cases demonstrated the "triple sign", and two high-grade SS showed a "cobblestone-like" appearance on T2-weighted imaging (WI). All time-signal intensity curves (TICs) were of the washout type. The mean apparent diffusion coefficient (ADC) values of the two high-grade cases were lower than those of the low-grade or intermediate-grade cases. Histopathologically, all but one was of the monophasic type. During the 8-40 month period of follow-up, recurrence occurred in four cases.

CONCLUSIONS

A sinonasal tumour exhibiting characteristic calcification and bony change, together with haemorrhage, "triple sign" or "cobblestone-like" appearance, should engender a diagnosis of SS.

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.

MR imaging and CT features of oncocytic papilloma of the sinonasal tract with comparison to inverted papilloma

OBJECTIVE:

To evaluate and compare the imaging feature of sinonasal oncocytic papilloma (OP) with inverted papilloma (IP).

METHODS:

The CT and MR imaging manifestations of 17 pathology proven sinonasal OPs were reviewed and compared with 17 IPs randomly selected as a control group over the same period.

RESULTS:

Seventeen sinonasal OPs had unilateral occurrence and 16 of them (94.1%) had a lobulated configuration.The distribution of original sites differed significantly between OPs and IPs (p < 0.05).OPs (47.1%) particularly involved the maxillary sinus,while IPs (64.7%) usually arose from the lateral nasal wall.OPs exhibited isointense in 5 cases and grape- or patchy-like hyperintense in 12 on T₁ weighted image, and isointense in 13 and hyperintense in 4 on T₂ weighted image, with moderate enhancement. 10 OPs appeared as a Type II time intensity curve (TIC).There was significant difference of pre-contrast T₁ signal intensity between OPs and IPs (p < 0.05).The prevalence of the imaging findings of "focal osteitis" (11.8% vs 94.1%) and "cystic change" (94.1% vs 17.6%) differed significantly between OPs and IPs (p < 0.05), but not for "cerebriform"sign (82.4% vs 94.1%) (p > 0.05).

CONCLUSION:

Three imaging features including high signal on T₁ weighted image, cystic change and only a rare association of focal osteitis may help the diagnosis of OP distinguished from IP.

ADVANCES IN KNOWLEDGE:

The typical imaging characteristics should prompt an accurate diagnosis of sinonasal OPs in routine clinical practice. Combination of CT and MR imaging characteristics can be more helpful in discriminating OPs from IPs.

Nasal septal schwannoma: a rare sinonasal tumour with certain peculiarities

Sinonasal schwannomas constitute 4% of head and neck nerve sheath tumours; however, schwannomas involving the nasal septum are quite rare. We present a 57-year-old male patient with nasal septal schwannoma who was managed successfully by endoscopic excision. 32 cases of septal schwannoma have been reported so far in the literature. This report discusses certain peculiar features exhibited by schwannomas of the nasal septum. Septal schwannoma does not show any age, sex or side predilection. However, they tend to involve posterior part of the septum and presumed to arise from the nasopalatine branch of the trigeminal nerve. Imaging findings of the sinonasal schwannoma are non-specific, but the histopathological characteristics are diagnostic, with seldom need for immunohistochemistry. Endoscopic excision is the safe and effective treatment option for the septal schwannoma of any size and location. Recurrence has not been reported in the literature following endoscopic excision.

[Imaging of the paranasal sinuses and anterior skull base]

Due to the complex anatomy of the anterior skull base and paranasal sinuses, radiologic diagnostics in this area are challenging. Magnetic resonance imaging (MRI) and computed tomography (CT) are the primary indicated modalities. Guidelines helping to select the appropriate modality have been published by the German Society of Head and Neck Radiology and the Society of Otorhinolaryngology. The present article presents an overview of the current radiologic procedures and their optimized implementation using clinical examples. These examples highlight the fact that a combination of at least CT and MRI is frequently required. Use of CT for intraoperative navigation is everyday practice in clinical routine. Occasionally, additional procedures such as angiography or myelography are necessary, particularly in cases of preoperative vascular diagnostics or embolization. Overall, evaluation of radiologic diagnostics in this area is complex; it requires experience and knowledge of the disease, as well as an understanding of the diagnostic procedures. Close collaboration between head and neck surgeons and radiologists is thus essential.