Peripheral nerve tumors involving paranasal sinuses: a case report and review of the literature

Unusual paranasal sinus solitary neurofibroma and literature review

Neurofibroma (NF) is a common benign peripheral neurogenic tumor that is rarely encountered in the paranasal sinus tract. In this report, we present a 55-year-old female who serendipitously discovered a maxillary sinus NF during a medical examination for a pulmonary nodule. The purpose of this article is to enhance medical practitioners' comprehension of paranasal sinus solitary NF by exploring cases, summarizing occurrences located in the paranasal sinus tract and conducting an organized review of paranasal sinus tract NF.

Malignant peripheral nerve sheath tumor of nasal cavity and paranasal sinus with 13 years of follow-up-A case report and review of literature

Although extremely rare, sarcomas including malignant peripheral nerve sheath tumors should be considered in the differential diagnosis of sino-nasal tract lesions. Long-term cure is possible through definitive operative management followed by adjuvant therapy.

[Nasal schwannoma with skull base destruction in a child (a case report and literature review)]

Schwannomas (neurinomas) are benign, encapsulated, and slow-growing neoplasms developing from any peripheral, cranial, or vegetative nerve that has the Schwann sheath. Schwannomas of the nasal cavity and paranasal sinuses in adults occur rarely, less than 4% of cases. The world literature lacks similar data for the pediatric age group because these tumors in children are unique and extremely rare. The most common clinical symptoms of sinonasal schwannoma are nasal breathing disorders, hyposmia or anosmia, and snoring at night. Other symptoms are associated with intranasal schwannoma invasion of neighboring organs and tissues and include exophthalmos, epiphora (lacrimation), headaches, and anesthesia in the facial area. In this article, we describe a rare case of diagnosis and successful surgical treatment of a child with intranasal schwannoma destructing the skull base.

Maxillary sinus schwannoma

Schwannoma (neurilemmoma) is a benign tumour that arises from the Schwann cells which cover the nerve sheaths of the peripheral or autonomic nervous system especially the sympathetic system. Reported cases of schwannoma arising from the sinonasal tract are rare. We report a case of a 28-year-old man who presented to otolaryngology-head and neck surgery clinic with left cheek swelling and left-sided nasal obstruction for 1-year period. Endoscopic examination and high-resolution CT scan revealed a homogenous expansile mass occupying the left maxillary antrum extending to the left orbit and left ethmoidal air cells. The mass was excised through endoscopic endonasal approach followed by Caldwell-Luc approach for the residual tumour. Postoperative histopathological examination revealed benign type Antoni A schwannoma.

Frontal sinus schwannoma

INTRODUCTION

Nasal sinus schwannomas are rare tumors, particularly in the frontal sinus.

CASE REPORT

The authors report the case of a woman with left frontal sinus schwannoma discovered in a context of frontal sinusitis with orbital and ocular complications. The surgical procedure consisted of endonasal tumor resection and external drainage.

DISCUSSION

The pathogenesis of frontal sinus schwannomas remains unclear. These tumors can present with a wide range of clinical and radiological signs, making them difficult to diagnosis. Surgical resection of these tumors is also complex.

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.

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.

Unusual Case of a Proptosed Eye: Isolated Right Maxillary Neurofibroma

Neurofibroma is a slow growing benign tumour of the peripheral nerve sheath which is frequently associated with neurofibromatosis type 1 (Prakash et al., 2014). Isolated solitary occurrence of neurofibroma in the maxillary sinus is rare with only 29 reported cases in the literature. We present a rare case of a 70-year-old gentleman who was referred to ENT with a right maxillary sinus neurofibroma with extension into the right inferior orbit. He has significant proptosis, ptosis, and limitation in abduction of the right eye. He has a complicated past history of multiple neurofibromas which were completely excised. Craniofacial MRI shows a large mass filling the right maxillary antrum extending anteriorly into subcutaneous tissue towards nasal ala and posterolaterally into inferior temporal fossa and superiorly into orbit and cavernous sinus involvement. Biopsy of the right maxillary mass revealed cellular spindle cell tumour with wavy collagen bundles within myxoid stroma which is consistent with a neurofibroma. Patient's case was discussed in the skull-base MDT and he has been referred to a specialist center for surgical removal of the neurofibroma with reconstructive surgery. Despite the rarity of this disease, otorhinolaryngologist should consider a possibility of neurofibroma of the paranasal sinuses.

Benign schwannoma of the maxillary antrum

Schwannoma also known commonly as neurilemmoma and schwann cell tumor is a benign nerve sheath tumor. About 1/3^rd cases of schwannoma arise from the head and neck region but rarely from the nasal and paranasal sinuses. The recurrence rate in these cases has reported to be very rare. We report a rare case of schwannoma in a 60-year-old woman arising from the maxillary sinus further eroding the orbital floor and nasal bone. We have also described the clinical presentation, radiological, histological findings, and management of the case.

Second primary malignant peripheral nerve sheath tumor of the paranasal sinuses after nasopharynx carcinoma

Malignant peripheral nerve sheath tumors are uncommon neoplasms that arise out of Schwann cells from the peripheral nerves, which rarely occur in the paranasal sinuses and nasal cavity. Especially with the increasing long-term survival of patients with nasopharynx carcinoma, second primary cancers can be diagnosed. Second primary cancers are not uncommon in patients with the prior radiation therapy. However, malignant peripheral nerve sheath tumor in the head and neck region after radiation is an exceedingly rare condition. We report the first case of malignant peripheral nerve sheath tumor of the paranasal sinuses as a second primary malignancy in a patient treated with radiation therapy for nasopharyngeal carcinoma 10 years ago.

Soft tissue tumors of the sinonasal tract

Primary soft tissue tumors arising in the sinonasal tract are rare. While many mesenchymal neoplasms have been reported in the nasal cavity, sinuses, and nasopharynx, few are distinctive to this anatomic region. Some tumor types are relatively more common in this area, such as schwannoma and rhabdomyosarcoma. Nasopharyngeal angiofibroma and sinonasal hemangiopericytoma are unique entities of the sinonasal tract, as well as the recently characterized biphenotypic sinonasal sarcoma. This review discusses the clinical, morphologic, and immunohistochemical features and currently known molecular data of the more frequently encountered soft tissue tumors of the sinonasal tract.

Endoscopic Resection of Sinonasal Tract Schwannoma: Presentation, Treatment, and Outcome in 10 Cases

BACKGROUND

Sinonasal schwannoma (SNS) is a rare sinonasal tract tumor whose presentation is similar to that of other benign nasal tumors. Very few case series appear in the literature. This study aims to describe the presentation, treatment, and outcome of 10 SNS cases from 3 referral centers.

METHODS

All SNS cases were analyzed retrospectively. Patient demographics, tumor data, surgical procedures, and outcome were recorded.

RESULTS

Five males and 5 females (mean age, 49.1 ± 21.4 years) were included in the study. The tumor was on the left side in 9 patients and on the right side in 1. It originated in the middle turbinate in 4 cases, the ethmoid and sphenoid sinuses in 2 cases, and the nasal septum and infratemporal fossa in 1 case each. Tumor resection was done endoscopically in all cases, and there was no need for an external procedure, and 5 patients did not require a sinusotomy. All 10 patients remained disease-free after a mean follow-up of 65.3 months (range, 2-120 months).

CONCLUSION

Safe and effective endoscopic resection of SNS is feasible. If the tumor is contained within the nasal cavity, simple tumor excision without sinusotomy can be enough to resect the tumor. In more extensive disease, a wider endoscopic approach may be needed, but an external approach was not necessary in this series.

Sinonasal Tract Neurofibroma: A Clinicopathologic Series of 12 Cases with a Review of the Literature

Neurofibroma (NF), a benign peripheral nerve sheath tumor, is very uncommon in the sinonasal tract, with only a few reported cases in the English literature. Cases within the files of the authors' institutions confined to the sinonasal tract were compared to cases reported in the English literature (Medline 1966-2014). The 12 patients included 6 females and 6 males, aged 26-75 years (mean 46.2 years). The patients usually presented clinically with a mass lesion (n = 11), obstruction (n = 4) or pain (n = 3), with an average symptom duration of 42.9 months. Two patients had neurofibromatosis (NF1). Tumors involved the nasal cavity alone (n = 8), maxillary sinus alone (n = 2), or mixed sites (n = 2), with a range of 0.4-4.1 cm (mean 2.2 cm). The tumors were circumscribed, composed of spindled to wavy cells with curvilinear nuclei set in a background of collagenized stroma and mast cells. Nuclear palisading and perivascular hyalinization were not seen. Mitoses were scant. Pleomorphism, necrosis and increased cellularity were absent. By immunohistochemistry, the lesional cells were S100 protein, SOX10 and NFP positive, while CD34 highlighted the perineurium. INI1 was intact, with strong nuclear expression in all cases. All patients had surgical excision without recurrence (mean follow-up 8.6 years). The principle differential diagnoses include schwannoma, perineurioma, fibromatosis, and solitary fibrous tumor. NF of the sinonasal tract occurs in middle-aged patients without a gender predilection, usually with non-specific symptoms present for a long duration. Tumors are relatively large (mean 2.2), and usually affect one site only. Surgery is curative, with only 16.7 % NF1 associated. S100 protein, SOX10 and NFP highlight the Schwann cells, with CD34 highlighting the perineural fibroblasts.

Neurofibroma of sinus maxillae

Neurofibroma is a benign tumour composed from Schwann cells. Localization in sinus maxillea is very rare. Authors presenting case which was treatment in Maxillo-Facial Surgery Clinic in Wrocław.

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.

Neurofibroma of paranasal sinuses - a case report

Primary neurogenic tumors in nose and paranasal sinuses are unusual entities. The majority of the reported cases have dealt with neurilemmomas and isolated neurofibromas are extremely rare. Here a case of neurofibroma of the paranasal sinuses is described.

Schwannoma of maxillary sinus

Schwannoma, also known as neurilemmoma, is a solitary, encapsulated peripheral tumour of neuroectodermal derivation that originates from schwann cells of neural sheath of motor/ sensory peripheral nerves or sympathetic nerves. About one- third of all schwannomas occur in head and neck region but nose and paranasal sinuses, are rare sites. We report a case of schwannoma arising from the maxillary sinus and eroding the orbital floor. To the best of our knowledge, this is the sixth; case of schwannoma solely arising in the maxillary sinus, reported in the literature.

Solitary neurofibroma of the frontal sinus

Isolated or solitary neurofibromas of the paranasal sinuses are rare. Mostly, they involve the maxillary sinus and so far, a solitary neurofibroma of the frontal sinus has never been reported in the literature. We present a case of frontal sinus neurofibroma treated successfully with surgical excision. A 28-year-old male presented with forehead swelling and computed tomography images revealed a tumor involving the left frontal sinus. Histopathological examination showed the tumor to be a neurofibroma. We discuss the clinical and pathological characteristics of neurofibroma arising in the nasal cavity and paranasal sinuses.

Trigeminal nerve tumors of the lateral skull base

A retrospective review of 8 trigeminal nerve tumors centered in the lateral skull base was carried out. Clinical manifestations, radiographic features, and outcome of management are detailed. Six patients in this series presented for primary surgery, and 2 patients had prior surgical interventions with incomplete resections.Surgical exposure via the infratemporal fossa (ITF) approaches resulted in complete tumor extirpation in all but I of the reoperated cases. Limited postoperative cranial neuropathies and the lack of intracranial complications are particularly notable in this series.A mean follow-up of 3 years revealed no evidence of recurrent disease. In the case of incomplete resection, there appears to be no appreciable growth of the small tumor remnant in the region of the cavernous sinus after 5 years.Trigeminal tumors of the lateral skull base with intracranial components below the level of the posterior clinoid process are ideally suited for the ITF techniques. The importance of securing the petrous carotid artery through a wide exposure is emphasized.

Solitary oral plexiform neurofibroma: review of literature and report of a case

Plexiform neurofibroma (PN) is a rare, benign tumor of nerve sheath origin, which frequently manifests as part of neurofibromatosis type 1. The article presents a case of solitary PN in a 4-year-old girl, which manifested as a double lip and without systemic or familial involvement. A review of the literature on solitary PN in the oral soft tissue demonstrates the scarcity of such cases.

Schwannomas of head and neck and review of literature

Benign nerve cell tumours have been given various names like schwannoma, neurilemmoma, neurinoma, neurofibroma, spindle cell tumours etc. Extra cranial head and neck schwannomas usually present as solitary and well-demarcated lesions. The lesion can cause secondary symptoms, such as nasal obstruction, dysphasia, and hoarseness, depending upon the location of the lesion. Fine needle aspiration cytology, CT scans, and MRI may be of limited help in the diagnosis of schwannomas. The treatment is complete surgical excision of the benign tumour and postoperative histopathological examination establishes the final diagnosis.

Endoscopic Excision of Solitary Neurofibroma Arising from Posterior Nasal Septum

Neurogenic tumors form a very small percentage of all neoplastic lesions of the head and neck region. However, the head and neck region is by far the most common location for benign peripheral neural tumors. Several cases involving the nasal cavity and paranasal sinuses have been sporadically documented throughout the medical literature. We present a rare case of a solitary neurofibroma arising from the posterior nasal septum of a 37-year-old woman. En bloc surgical resection of the mass was achieved by endoscopic approach. This case highlights the importance of considering this clinical entity in the differential diagnosis when encountering a unilateral soft tissue mass in the nasal cavity and use of endoscopic technique in the management of such tumors.

Abbreviations

Contrast enhanced computed tomography (CECT), Magnetic resonance imaging (MRI).

Solitary nasal schwannoma clinically presenting as an angiofibroma of the nasopharynx

Benign schwannomas of the nasal cavity are rare. When they do occur, their clinical presentation is variable, and some are fairly vascular. We report the case of a 17-year-old boy who presented with epistaxis associated with a unilateral nasal mass that extended into the nasopharynx. The tumor was removed via a transpalatal approach. In most such cases, a clinical diagnosis of angiofibroma is made. In this case, however, histopathologic examination identified the lesion as a schwannoma.

Single-stage total endoscopic resection of a plexiform neurofibroma of the maxillary sinus in a child with type 1 neurofibromatosis

Plexiform neurofibromas are peripheral nerve sheath tumors associated with neurofibromatosis type 1. The maxillary sinus is an extremely rare location of the plexiform neurofibroma and only two adult cases have been previously reported. We report the first case of plexiform neurofibroma of the maxillary sinus occurring in a child with neurofibromatosis type 1. This unusual location presents a management challenge considering the infiltrative nature and the potential malignant degeneration of this type of tumor. MRI is highly valuable to diagnose and plan the surgical approach of the plexiform neurofibroma of the maxillary sinus. Due to the location of the tumor and the patient's age, conservative surgery is highly recommended. We performed an endoscopic total en-bloc resection of the tumor with no recurrence after nine months of follow-up.

[Schwannoma of the nasal cavity: a case report]

Schwannomas of the nasal cavity and paranasal sinuses are quite rare, with 4% occurring in this location. Most of them are benign and do not recur when totally removed by surgery. It is very important to distinguish between schwannoma and primary benign neurofibroma. Neurofibromas are lesions having the possibility for malignant transformation and recurrence. A case of schwannoma in the nasal cavity is reported, and the diagnostic and therapeutic procedures, as well as recommendations from the literature, are described. The histological and immunohistochemical features are discussed in detail to draw a distinction between schwannoma and neurofibroma. In cases of intranasal and paranasal lesions, the existence of a schwannoma must be considered. Differentiating between schwannoma and neurofibroma is important for estimating the risk of malignant transformation and recurrence.

A schwannoma in the nasal septum

Schwannomas of the sinonasal tract are very rare neoplasms. We present the case of a schwannoma developing in the nasal septum. The patient was a 51-year-old woman with the complaint of unilateral nasal obstruction. We completely removed this tumor by an endoscopic approach. We discuss the clinical presentation, differential diagnosis, and treatment of this rarely encountered neoplasm.

Benign schwannoma in paranasal sinuses: a clinico-pathological study of five cases, emphasising diagnostic difficulties

OBJECTIVES

To highlight the difficulty in making a correct diagnosis of benign schwannoma in the paranasal region, to raise awareness of this rare condition, and to suggest the most appropriate treatment.

METHOD

Retrieval of cases retrospectively from archives of the histopathology department of a major UK cancer centre with central review of all cases.

RESULTS

Five cases were identified since 1990 and clinical and pathological features are summarised. Median follow up of patients was 8.1 years. Radiological appearances of local bone invasion and histological features of tumour unencapsulation and hypercellularity could give the mistaken impression of malignant disease and lead to unnecessary over-treatment.

CONCLUSION

Central pathological review and clinical awareness is required. Although local recurrence can occur, the prognosis is excellent. The treatment of choice is local excision. Radiotherapy can be considered, but in most cases it would incur unnecessary morbidity.

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.

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.

Intranasal schwannoma in a young woman

A rare case of a schwannoma arising from the middle meatus in a 24-year-old woman is reported. The patient presented with a 12-month history of right-sided nasal obstruction, rhinorrhoea, anosmia, headache and recurrent minor nosebleeds. Examination of the right nasal cavity revealed a polypoidal mass. Computerised tomography showed the mass completely occluding the nasal passage with evidence of a secondary maxillary sinusitis. She underwent a complete intranasal excision of the polypoidal mass which was arising from the right middle meatus. The histological features of the lesion were consistent with a schwannoma including diffuse immunoreactivity for S-100 protein. This case illustrates the need to consider schwannoma, amongst many other lesions, in the differential diagnosis of a unilateral nasal mass and reinforces the established principle of sending all material removed from the nose for histological examination.

Schwannoma of the sinonasal tract: a clinicopathologic and immunohistochemical study of 5 cases

CONTEXT

Peripheral nerve sheath tumors are soft tissue neoplasms rarely encountered in the nasal cavity and paranasal sinuses.

OBJECTIVE

To describe the clinicopathologic and immunohistochemical features of a series of schwannomas of the sinonasal tract.

DESIGN

Surgical pathology files were searched for the diagnosis "sinonasal schwannoma." All histologic documents and clinical data were reviewed. Immunohistochemistry was performed on paraffin-embedded tissue with antibodies to S100 protein, epithelial membrane antigen, CD34, and MIB-1. RESULSTS: Five cases of sinonasal schwannoma were retrieved; patients included 3 women and 2 men, aged 20 to 56 years. Three cases were located in the ethmoid sinus. Clinical symptoms were nonspecific (nasal obstruction, epistaxis, and anosmia). All tumors were treated with conservative surgical resection. Pathologic examination showed a spindle cell proliferation without encapsulation in all cases. No cytologic atypia was seen, and the mitotic activity was low (<3 mitotic figures/10 high-power fields). Immunohistochemistry showed diffuse positivity with S100 protein and negativity with CD34 and epithelial membrane antigen. MIB-1 staining was low (1%-5% of tumor cell nuclei stained). During the follow-up (median, 6 years), no recurrence or metastasis was observed.

CONCLUSIONS

Schwannoma is a very unusual tumor of the sinonasal tract and is associated with nonspecific symptoms. Histologically, sinonasal schwannomas differ from schwannomas of other locations by their lack of a peripheral capsule and possible ulceration of the epithelial covering. Sinonasal schwannomas are treated with conservative surgical resection and have an excellent prognosis.

Solitary Malignant Schwannoma of the Nasal Cavity and Paranasal Sinuses: Report of Two Rare Cases

Malignant schwannomas of the paranasal sinuses are extremely uncommon tumors, as only 18 well-documented cases have been previously published in the English-language literature. We report two new cases of solitary malignant schwannoma—one in a 23-year-old man and the other in a 45-year-old woman. Neither was associated with von Recklinghausen's disease. These tumors involved the maxillary sinus, nasal cavity, and orbit and extended intracranially. Following surgery, both patients experienced recurrences. The male patient developed a slowly enlarging intranasal mass at the same site 8 years following excision of the original tumor and postoperative radiotherapy. Microscopic examination of the recurrent tumor revealed that its features were similar histologically to those of the original. The female patient experienced a recurrence 1 year following her first operation.

Cystic schwannoma of the maxillary sinus

OBJECTIVE

Although 25-45% of all schwannomas are reported to occur in the head and neck region, nasal cavity and paranasal sinus involvement is rare, with 32 such cases described till 1999. Of these cases, only three were cystic. Herein we present a cystic schwannoma of the maxillary sinus of a 66-year-old, otherwise healthy male patient.

METHODS

The tumor tissue was routinely processed, embedded in paraffin, and stained with H&E. Immunostaining was performed for S-100 protein, epithelial membrane antigen (EMA) and cytokeratin.

RESULTS

A mass with sudden enlargement, inhomogeneous enhancement with cystic areas, S-100 positive membrane-like structures lining the cystic cavity of an otherwise classical schwannoma were the main features encountered in our case.

CONCLUSION

We recommend that cystic schwannoma should be kept in mind in the differential diagnosis of cystic masses of the maxilla.

Naso-ethmoid schwannoma with intracranial extension: case report

Intranasal schwannomas are rare lesions, specially when they present with an intracranial extension. The fifth case in the medical literature of a naso-ethmoid schwannoma with extension into the anterior cranial fossa is presented. The magnetic resonance findings and the details of the combined intracranial / transfacial operative approach used are described. The possible origin and the clinical characteristics of this rare lesion are reviewed.

Extended frontal approach with bilateral orbitofrontoethmoidal osteotomies for removal of a giant extracranial schwannoma in the nasopharynx, sphenoid sinus, and parapharyngeal space

BACKGROUND

Although parapharyngeal schwannomas are not uncommon, schwannomas of the nasopharynx and paranasal sinuses are rare lesions. In the absence of intracranial extension, they are usually removed with transantral, lateral rhinotomy or more complex transfacial approaches.

CASE DESCRIPTION

We report a 24-year-old patient with a giant benign schwannoma involving the superior parapharyngeal space, pterygopalatine fossa, nasopharynx, and sphenoid sinus with erosion into the clivus that was removed with an extended frontal approach including bilateral orbitofrontoethmoidal osteotomies.

CONCLUSION

The advantages of the extended subfrontal over more standard transfacial approaches for lesions in this location include the early dissection of critical neural structures, preserving cosmetics and facilitating management of an inadvertent cerebrospinal fluid leak.

Factors in the pathogenesis of tumors of the sphenoid and maxillary sinuses: a comparative study

OBJECTIVES/HYPOTHESIS

To explain the processes that lead to the development of tumors in the maxillary and sphenoid sinuses.

STUDY DESIGN

A 32-year review of the world's literature on neoplasms of these two sinuses and a randomized case-controlled study comparing the normal mucosal architecture of the maxillary to the sphenoid sinus.

METHODS

Analysis of a 32-year world literature review reporting series of cases of maxillary and sphenoid sinus tumors. Tumors were classified by histological type and separated into subgroups if an individual incidence rate was reported. Histomorphometry of normal maxillary and sphenoid sinus mucosa was performed in 14 randomly selected patients (10 sphenoid and 4 maxillary specimens). Specimens were fixed in 10% formalin, embedded in paraffin, and stained with periodic acid-Schiff (PAS) and hematoxylin. Histomorphometric analysis was performed with a Zeiss Axioscope light microscope (Carl Zeiss Inc., Thornwood, NY) mounted with a Hamamatsu (Hamamatsu Photonics, Tokyo, Japan) color-chilled 3 charge coupled device digital camera. The images were captured on a 17-inch Sony (Sony Corp., Tokyo, Japan) multiscan monitor and analyzed with a Samba 4000 Image Analysis Program (Samba Corp., Los Angeles, CA). Five random areas were selected from strips of epithelium removed from each sinus, and goblet and basal cell measurements were made at magnifications x 100 and x 400.

RESULTS

The literature review revealed that the number and variety of tumors in the maxillary sinus are much greater than those in the sphenoid. The incidence of metastatic lesions to each sinus is approximately equal. No recognized pattern of spread from any particular organ system could be determined. On histomorphometric study there were no statistically significant differences between the sinuses in the concentration of goblet cells, basal cells, or seromucinous glands.

CONCLUSIONS

Factors involved in the pathogenesis of tumors of the maxillary and sphenoid sinuses include differences in nasal physiology, embryology, morphology, and topography. There are no significant histological differences in the epithelium and submucous glands between the two sinuses to explain the dissimilar formation of neoplasms.

Malignant schwannoma of the sinonasal tract

Malignant Schwannoma of the sinonasal tract is an extremely rare tumour. So far, only 19 cases have been reported in the literature. We report herein a case of malignant schwannoma involving nasal cavity, maxillary antrum and ethmoid sinus in a 60-year-old male patient. The patient was treated with surgery and post-operative radiotherapy. He currently remains free of the disease 15 months after the diagnosis and twelve months after completing therapy.

Infantile schwannoma of the maxillary sinus

A rare case of a 5-year-old female with schwannoma of the maxillary sinus is presented. She had complained of painless swelling of the left cheek and hard palate for a duration of one year. Preoperatively, a CT scan strongly suggested it to be a maxillary cyst with an erupted tooth rather than neoplasm. The tumour was completely removed after embolization of the left internal maxillary artery. The tumour was composed of spindle cells in a palisading pattern and intercellular collagenous fibres. Mitotic figures and atypical nuclei were not observed. Immunohistochemically, the majority of the cells were positive for NSE and S-100 protein, whereas GFA and PCNA showed little immunoreaction. The pathological diagnosis was Antony type A of schwannoma arising in the maxillary sinus.

Malignant schwannoma of nasal cavity

A rare case of schwannoma of nasal cavity arising from ethmoid region with malignant transformation is reported. It's clinical features histopathology and surgical managements are discussed.

Cystic Schwannoma of the Sphenoid Sinus and Skull Base

Skull base and intracranial cystic schwannomas are rare tumors. To our knowledge, a cystic schwannoma involving the sphenoid sinus has not been previously reported. The location and fluid-filled nature of the lesion resulted in an erroneous preliminary diagnosis of a destructive sphenoid sinus mucocele. Endoscopic biopsy and decompression established the correct diagnosis and reversed a progressive visual loss until definitive surgical removal of the lesion was accomplished. Diagnostic evaluation, histologic findings and management strategies are discussed.

Malignant sinonasal epithelioid schwannoma

Malignant schwannomas are rare neoplasms that are seldom found in the head and neck. Few cases have been reported involving paranasal sinuses and none of them was of the "epithelioid" type. In this report, an unusual case of epithelioid malignant schwannoma involving the maxillary sinus, nasal cavity and orbit is presented. The patient was a 27-year-old male with a history of headache, nasal obstruction and epistaxis. Histologically, the tumour had a biphasic pattern with spindle and epithelioid elements which led to a differential diagnosis with malignant melanoma. It had also to be distinguished from other neoplasms, such as squamous cell carcinoma and olfactory neuroblastoma because of it location. Immunohistochemical positivity for S-100 protein, glial fibrillary acidic protein and vimentin together with negativity for HMB-45 and cytokeratins, as well as mesaxon formation detected with electron microscopy were conclusive in the diagnosis. The patient was treated with surgical excision and radiotherapy but local recurrence and metastases occurred, and he died within 1 year after initial diagnosis.

Schwannoma of the anterior cranial fossa and paranasal sinuses

Only two cases of schwannomas involving the anterior cranial fossa and paranasal sinuses or nasal fossa have been reported previously. We describe a third case which involved all of these structures and also the left orbit.

Benign nasal schwannoma

Nerve sheath tumours of the head and neck region mainly involve the eighth cranial nerve with only 4 per cent occurring in the paranasal sinuses. Only 32 cases of benign schwannomas occurring in the paranasal sinuses have been reported. We present a further case, review the current literature, and discuss the clinical details and specific histological features.