Transpterygoid approach to a dermoid cyst in pterygopalatine fossa.
ABSTRACT: Objective To describe a case of dermoid cyst arising from the pterygopalatine fossa and review the literature. Methods We report a case of a 23-year-old man who suffered a car accident 2 years before otolaryngologic attendance. He had one episode of generalized tonic-clonic seizure and developed a reduction of visual acuity of the left side after the accident. Neurologic investigation was performed and magnetic resonance imaging revealed an incidental finding of a heterogeneous ovoid lesion in the pterygopalatine fossa, hyperintense on T2-weighted imaging. Results Endoscopic sinus surgery with transpterygoid approach was performed. The ovoid lesion was noted in the pterygopalatine fossa. Puncture for intraoperative evaluation showed a transparent thick fluid. Surprisingly, hair and sebaceous glands were found inside the cyst capsule. The cyst was excised completely. Histologic examination revealed a dermoid cyst. The patient currently has no evidence of recurrence at 1 year postoperatively. Conclusion This unique case is a rare report of a dermoid cyst incidentally diagnosed. An endoscopic transnasal transpterygoid approach may be performed to treat successfully this kind of lesion. Although rare, it should be considered in the differential diagnosis of expansive lesions in the pterygopalatine fossa, including schwannoma, angiofibroma, esthesioneuroblastoma, osteochondroma, cholesterol granuloma, hemangioma, lymphoma, and osteoma.
Project description:Spontaneous meningoencephalocele (SME) of the sphenoid wing is a rare cause of cerebrospinal fluid (CSF) leakage. Surgical closure of the fistula is usually required. The approach taken depends on the location of the defect and the extension of the meningoencephalocele. The endoscopic transpterygoid approach may be useful. We prospectively analyzed the three cases of SME of the sphenoid wing with lateral sphenoid sinus extension treated endoscopically at Stanford over the last 3 years with regard to imaging findings, operative technique, and operative morbidity. In our three cases, the extent of pterygopalatine fossa (PPF) exposure undertaken, complete in one and partial in two, depended on the defect site. Follow-up ranged from 17 to 25 months. The fistula was completely closed in all three cases. Extant literature reports a 97% rate of successful closure (N = 65 of 67, with a mean follow-up of 25 months) and no major complications. Endoscopic transpterygoid repair is a useful, safe alternative to traditional approaches for repair of SME of the sphenoid wing. Its feasibility depends on the site of the defect, which can be identified by preoperative imaging. Larger PPF exposure and postoperative lumbar drainage of CSF can be useful and have a low risk of morbidity.
Project description:Background:Endoscopic endonasal transpterygoid (EET) approach is well suited for trigeminal schwannomas.Case Description:A 25-year-old female presented with the right hemifacial pain for 1 month. Examination revealed mild sensory loss to both touch and pain in the right V2 and V3 dermatomal distribution. On magnetic resonance imaging, a well-defined extra-axial lesion was seen in the right infratemporal fossa extending intracranially, widening the foramen ovale. Erosion of the lateral pterygoid plate was evident on computed tomography. Diagnosis of a trigeminal schwannoma was made and excision through endoscopic transnasal transpterygoid approach was planned. After adequate nasal decongestion, lateralization of the inferior turbinate followed by medialization of middle turbinate done to expose the posterior part of the lateral nasal wall. Sphenopalatine foramen was visualized and the branches of the sphenopalatine artery to turbinate were coagulated followed by partial inferior and middle turbinectomy. Next, antegrade uncinectomy, bullectomy, and middle meatal antrostomy performed. Anterior and posterior ethmoidectomy was done to gain access to the sphenoid sinus. Medial maxillectomy done, posterior maxillary sinus wall exposed and drilled to reach infratemporal fossa harboring the tumor. The lateral recess was further exposed to visualize the vidian and maxillary nerves. Palatine bone and pterygoid body along with the medial pterygoid plate were completely drilled to expose the tumor capsule, which was gently dissected off. Complete tumor excision was performed uneventfully.Conclusion:EET provides a good oncological and functional outcome. With a lesser risk of surgical morbidities, it is an excellent alternative to conventional skull base approaches to trigeminal schwannomas in the modern era.
Project description:Epidermoid cysts (ECs) are benign congenital cysts that typically develop from misplaced stratified squamous epithelium during neural tube closure. They are most commonly encountered in the cerebellopontine angle, the fourth ventricle, and the region of the sella turcica. Recurrence of an EC or regrowth of residual components following surgery is known to occur, but the exact incidence is not defined. Repeat surgical removal is generally considered but may be complicated by significant morbidity. We present a novel endoscopic method by which to manage a recurrent EC of the infratemporal fossa using a silastic stent through a transpterygoid approach that permits periodic drainage of recurrent cyst material in the outpatient setting with minimal morbidity.
Project description:Background Intracranial dermoid cysts are rare tumors of congenital origin. We report a case of a large dermoid tumor arising in the infratemporal fossa (ITF) with erosion into the middle cranial fossa. After reviewing the literature, we believe this represents the first reported dermoid tumor of the ITF with extension into the middle cranial fossa. Results A 21-year-old women presented with a large cystic mass involving the left infratemporal fossa and middle cranial fossa that was discovered following a motor vehicle collision. Neurologic examination was normal. The mass was resected through a frontotemporal extradural approach with endoscopic assistance. Imaging studies, gross findings, and histopathology were consistent with a dermoid tumor. Conclusion This is the first report of a dermoid cyst arising in the ITF with extension into the middle cranial fossa. We suggest including dermoid tumor in the differential diagnosis of cystic abnormalities in this region. Complete resection of the cyst remains the preferred treatment with surgical approach guided by preoperative imaging.
Project description:Introduction Endonasal endoscopic transpterygoid approaches are commonly used techniques to access the infratemporal fossa and parapharyngeal space. Important endoscopic endonasal landmarks for the poststyloid parapharyngeal space, hence the internal carotid artery, include the mandibular nerve at the level of foramen ovale and the lateral pterygoid plate. This study aims to define the anatomical relationships of the foramen ovale, establishing its distance to other important anatomical landmarks such as the pterygoid process and columella. Methods Distances between the foramen ovale, foramen rotundum, and fixed anatomical landmarks like the columella and pterygoid process were measured using computed tomography (CT) scans and cadaveric dissections of the pterygopalatine and infratemporal fossae. Results The mean distances from the foramen ovale to columella and from the foramen rotundum to columella were found to be 9.15 cm and 7.09 cm, respectively. Analysis of radiologic measurements detected no statistically significant differences between sides or gender. Conclusions The pterygoid plates and V3 are prominent landmarks of the endonasal endoscopic approach to the infratemporal fossa and poststyloid parapharyngeal space. A better understanding of the endoscopic anatomy of the infratemporal fossa and awareness of the approximate distances and geometry among anatomical landmarks facilitates a safe and complete resection of lesions arising or extending to these regions.
Project description:Chondrosarcomas of the skull base are rare tumors that present difficult management considerations due to the pathoanatomical relationships of the tumor to adjacent structures. We present the case of a 25-year-old female patient presenting with a chondrosarcoma of the right petrous apex extending inferiorly, medial to the cranial nerves. The tumor was resected via an endoscopic endonasal infrapetrous transpterygoid approach that achieved complete resection and an excellent long-term outcome with no complications. Technical nuances and potential pitfalls of the case are discussed in depth including measures to protect the carotid artery while performing the required drilling of the skull base to access the lesion.
Project description:Dermoid cysts are rare in the skull base. There have been 10 reported cases of dermoid cysts in the cavernous sinus, two in the petrous apex, and one in the extradural Meckel cave. This is the first case report of a dermoid cyst in the anterior infratemporal fossa attached to the anterior dura of the foramen ovale. The clinical presentation, radiologic findings, histologic features, tumor origin, and operative technique are described along with a review of the literature.
Project description:To provide a new approach for the treatment of tumor in Meckel's cave, by dissecting adjacent structures of the nasal cavity-maxillary sinus-pterygopalatine fossa-Meckel's cave approach.Fifteen adult cadaver heads (30 sides) were dissected and the correlated anatomic landmarks were observed, measured and analyzed in an operative route.The approach was divided into 3 steps: entering the maxillary sinus, the later pterygopalatine fossa and the final Meckel's cave. Safe access to Meckel's cave could be achieved by tracing the vidian neurovascular bundles and dissecting the quadrangular space (QS). The distances from the nasal columella to the apertura maxillaries, the sphenopalatine foramen, and the anterior foramen of the pterygoid canal were (44.08+/-2.61) mm, (64.83+/-2.42) mm, and (70.43+/-2.94) mm, respectively. The angles between the horizontal plate of the palatine bone and the link from nasal columella to apertura maxillaries, between the horizontal plate of the palatine bone and the link from nasal columella to sphenopalatine foramen were (38.10+/-2.46) degrees and (26.15+/-2.26) degrees , respectively.The endoscopic approach of transnasal maxillary sinus-pterygopalatine fossa-Meckel's cave (ENMPA) is a safe and direct way to access Meckel's cave, and could be employed for the treatment of tumor in Meckel's cave.
Project description:<h4>Background</h4>Dermoid cysts are well-known lesions that manifest as subcutaneous tumors around the lateral sides of the eyebrows in young patients. Computed tomography or magnetic resonance imaging (MRI) is often performed to confirm the diagnosis. On the other hand, a lipoma is usually a circular lesion, which is sometimes observed in the upper part of the face. The signals of both T1-weighted and T2-weighted images of MRI of a lipoma are, in general, relatively highly homogenous, and the signals decrease in fat-suppressed images. Therefore, differential diagnosis between a dermoid cyst and a lipoma is usually made with MRI, especially based on fat-suppressed images. Here, we present a case of misdiagnosis of a dermoid cyst as a lipoma because of atypical magnetic resonance images.<h4>Case presentation</h4>We report a case of a 24-year-old Japanese woman with a dermoid cyst around the lateral edge of the eyebrow. The cyst had been gradually increasing in size for the past 2 years. On MRI, it showed high internal signals on T1- and T2-weighted images. However, the signal intensity decreased homogeneously in the fat-suppressed T2-weighted images. The observed tumor had a yellowish appearance under the endoscope. On the basis of these findings, the lesion was considered a lipoma until it ruptured intraoperatively. The pathological diagnosis confirmed it to be a dermoid cyst.<h4>Conclusion</h4>Some dermoid cysts contain lipid-rich liquid, and these may be misdiagnosed as lipomas by MRI. When a tumor is located at a common site for a dermoid cyst, the MRI images should be validated carefully if it appears like a lipoma, and the differential diagnosis should be considered carefully.
Project description:Introduction A nasolabial cyst is an ectodermal development cyst. It presents as a fullness of canine fossa, nasal ala, or vestibule of the nose. It is rare and usually small. Treatment consists of complete surgical excision or transnasal endoscopic marsupialization. Objective To describe a giant nasolabial cyst case treated using Neumann incision. Case Report A 37-year-old man was referred to the otolaryngology department with nasal obstruction and nasal deformity. Computed tomography showed a nasal cystic lesion 4 × 4.5 × 5 cm wide. Surgical excision using Neumann incision was performed. Discussion Neumann incision provides wide access to the nasal cavity and may be useful in nasolabial cyst treatment.