Malignant schwannoma of the sinonasal tract

Pediatric Pterygopalatine Fossa Schwannoma Presenting as Vision Loss: A Case Report and Literature Review

Neurosynovial tumors, originating from Schwann cells within nerve sheaths, are benign entities, with 25% to 45% manifesting in the head and neck region. However, occurrences in the pterygopalatine fossa (PPF) are exceptionally rare, and only a handful of cases have been documented. In this report, we present the unique case of a 6-year-old child exhibiting a sizable soft tissue mass in the left PPF, extending into the inferior orbital fissure. The patient underwent successful intranasal endoscopic removal of PPF schwannoma utilizing the prelacrimal recess approach, with postoperative pathology confirming the diagnosis of schwannoma. Schwannomas within the PPF are particularly uncommon, and instances of such tumors in pediatric patients are even more exceptional. This case highlights the diagnostic and therapeutic challenges associated with PPF schwannomas in children, emphasizing the significance of a multidisciplinary approach for optimal management. In addition, a comprehensive literature review is presented to provide insights into the existing knowledge on this rare entity, further contributing to the understanding of pediatric PPF schwannomas.

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.

Malignant peripheral nerve sheath tumour of the maxilla

A 38-year-old man was diagnosed with malignant peripheral nerve sheath tumour of the maxilla. He was treated with total maxillectomy. Histopathological examination of the resected specimen revealed a close resection margin. The tumour was of high grade with an MIB-1 labelling index of almost 60%. At six weeks following the surgery, he developed local tumour relapse. The patient succumbed to the disease at five months from the time of diagnosis. The present report underlines the locally aggressive nature of malignant peripheral nerve sheath tumour of the maxilla which necessitates an early therapeutic intervention. A complete resection with clear margins is the most important prognostic factor for malignant peripheral nerve sheath tumour in the head and neck region. Adjuvant radiotherapy may be considered to improve the local control. Future research may demarcate the role of targeted therapy for patients with malignant peripheral nerve sheath tumour.