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.

BACKGROUND: Schwannomas are well-differentiated, benign tumours that originate from the Schwann cells of nerve sheaths. They constitute 25-45% of all the head and neck tumours and can cause significant morbidity depending on the site of origin. The pterygopalatine fossa is the rarest site of involvement, with only a few cases reported in the literature.
METHODS: This is the case of a 46-year-old male who presented with a twelve [12] month history of left-sided facial pain and progressive swelling. Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) revealed a large soft tissue lesion located in the left pterygopalatine fossa (PPF). Surgical management is presented, and technical details of the repair are discussed. At one year follow-up, there were no signs of recurrence, and the cosmetic outcome was satisfactory.
CONCLUSIONS: This case is one of a handful of reported cases of PPF schwannomas in the English literature. Although a significant percentage of schwannomas arise in the head and neck region, the pterygopalatine fossa is the rarest site of involvement. Due to its clinically inaccessible location and complex connections, the pterygopalatine fossa can act as a natural conduit for the spread of inflammatory and neoplastic diseases in the head and neck.
CONCLUSIONS: Currently, the endoscopic endonasal approach (EEA) is preferred due to its safety and good oncologic outcome. There is also decreased morbidity as it is minimally invasive. Furthermore, surgeons embarking on the EEA should be equipped with an image guidance system and be trained in advanced endoscopic techniques. However, the open approach remains a reliable and proven surgical method to treat large tumours located within this intricate and inaccessible area.

Metastatic skull base malignancies infrequently occur but, when present, typically arise from breast malignancies. Pterygopalatine fossa (PPF) metastasis of any malignancy is further seldom reported, and metastasis of gynecologic malignancies to the PPF has not been previously described in the literature. We present a single case of a 42-year-old female with the first likely case of high-grade endometrial sarcoma metastatic to the PPF. The patient presented with facial pain and numbness in the V2 distribution presented for evaluation. History was significant for several months of dysmenorrhea and metrorrhagia. Computed tomography, magnetic resonance imaging, and positron emission tomography imaging revealed a PPF mass with local extension and bony metastases. Endoscopic biopsy was performed, and final pathology was most consistent with metastatic high-grade endometrial stromal sarcoma. This is the first reported case of likely metastatic endometrial sarcoma to the PPF. This case report highlights the possibility of rare distant metastasis of gynecologic malignancy to this area of the skull base.

In this review about extraoral anatomy as depicted by cone beam computed tomography, the retromaxillary region is discussed. A medium-sized (6 x 6 cm) or large (≥ 8 x 8 cm) field of view of the maxilla will inevitably depict the retromaxillary region that can be considered a «transition» zone between the viscerocranium and the neurocranium. Major structures of the region include the sphenoid bone and the pterygopalatine fossae. The sphenoid bone is a single but complex bone located between the maxilla and the brain. It is composed of a central body, bilateral greater and lesser wings, and pterygoid processes. Important neurovascular structures pass through the sphenoid bone: the optic nerve and the ophthalmic artery via the optic canal, the maxillary nerve via the foramen rotundum, and the pterygoid nerve via the Vidian canal. The central body of the sphenoid bone also contains the highly variable sphenoid sinus that is the most posteriorly located paranasal sinus. The bilateral pterygopalatine fossae behind the maxillary sinuses contain several important neurovascular structures that supply the maxilla and the midface.

Blockade of the trigeminal nerve and its branches is an effective diagnostic tool and potential treatment of facial pain. Ultrasound-guided injections in the pterygopalatine fossa (PPF) to block the trigeminal nerve divisions and sphenopalatine ganglion have been described but a consensus has yet to be reached over the ideal approach. We sought to delineate and compare the various approaches to the ultrasound-guided trigeminal divisions blockade via the PPF.
The literature search was performed by searching the National Library of Medicine\'s PubMed database, the Cochrane Database of Systematic Reviews and Google Scholar within the date range of January 2009-March 2019 for keywords targeted toward \"trigeminal nerve,\" \"maxillary nerve,\" or \"pterygopalatine fossa,\" \"ultrasound,\" and \"nerve block,\" using an English language restriction. Six papers were included in the final review: one prospective double-blinded randomized controlled trial, one prospective descriptive study, one case series, two case reports, and one cadaveric study.
There are three main approaches to the ultrasound-guided trigeminal nerve branches blockade via the PPF: anterior infrazygomatic in-plane, posterior infrazygomatic in-plane, and suprazygomatic out-of-plane approaches. Each showed injectate spread to the PPF in cadaver, adult and pediatric patients, respectively.1-5 Injectate used varied from 3 to 5 mL to 0.15 mL/kg.
These studies demonstrated that the PPF is a readily accessible target for the ultrasound-guided maxillary nerve block via three main approaches.2 The ideal approach is yet to be determined and must be further explored.

To demonstrate the affection of skull base by mucormycosis in an immunocompetent individual. Mucormycosis is an opportunistic infection principally seen in immunocompromised individuals, but recently being increasingly recognized in otherwise healthy individuals. Skull base involvement secondary to otogenic nidus, mimicking otitis media was rarely reported. A 34 year-old male, an otherwise healthy patient presented with facial nerve palsy followed by trismus, neck swelling and neck stiffness. Radical mastoidectomy with tympanoplasty and Facial nerve decompression along with Endoscopic guided debridement of sinuses and pterygopalatine fossa followed by medical treatment for 14 weeks. Facial nerve functioning, dry ear canal and relief from other symptoms. Surgical debridement and post op Anti fungal treatment improved the facial nerve function to House brackmann grade-II and also provided relief from trismus and stiffness and improved the overall general condition of the patient. Mucor is a saprophytic organism, which can cause extensive progression, regardless of the immune status. To the best of our knowledge, this is one of the very few rare cases that have been reported in the context of skull base mucormycosis in immunocompetent individuals. Surgical debridement followed by anti fungal therapy continues to remain the mainstay of treatment.

BACKGROUND: The pterygopalatine fossa (PPF) infiltration is performed to reduce blood flow during endoscopic sinus surgery and septorhinoplasty, as well as to control posterior epistaxis and provide regional anesthesia in dental procedures. PPF infiltration performed with consideration of the morphometrics of greater palatine foramen (GPF), greater palatine canal (GPC) and PPF would increase the success of the procedure and reduce the risk of complications. The aim of this study is to investigate the GPF, GPC, lesser palatine foramen (LPF), lesser palatine canal (LPC) and PPF morphology via the images obtained by CBCT, to provide information for interventional procedures.
METHODS: GPF, GPC, LPF, LPC and PPF were morphometrically evaluated retrospectively in CBCT images of 75 female and 75 male cases by Planmeca Romexis program. The 19 parameters were measured on these images.
RESULTS: These parameters were evaluated statistically. The comparison of these parameters by genders revealed significant differences in distances between GPC-PC, PC-IOF, LPC-GPF, GPF-MS in the coronal and transverse planes, the distance between GPF and the occlusal plane of the teeth, GPF-PNS, GPF-IF and TD-GPF, and in the area of GPF. The number of LPF was found ranging from 1 to 5.
CONCLUSIONS: Our results may help to insert to needle properly for application of maxillary nerve block with a high success rate and minimal complication. We recommend that the needle should be inserted 14-15 mm lateral to the midsagittal plane, 19-20 mm over the occlusal plane of the teeth and on the same line with the third molar teeth. For PPF infiltration through the GPF, the needle should be pushed forward 28 mm upward at 66° angle on the transverse plane and 14°-15° angle on the vertical plane.

We report a case which involves the maxillary sinus by original of synovial sarcoma of infratemporal fossa and pterygopalatine. A 40-years-old man presented with a history of tumor under the earlobe. It is derived from the synovial sarcoma under temporal fossa after tumor excision. The patient is limited to open his mouth and nasal obstruction. The nasal pathologic examination consider synovial sarcoma.We report the case to improve doctors\' comprehension of its pathogenesis,clinical manifestations,teeatment and prognosis.

The oral cancer with masticator-space involvement is classified as T4b disease. The limited data suggest that the masticator space is a complex anatomic area and tumors with varying degrees of infiltration may have different oncologic outcomes. It is not advisable to group all T4b tumors as one and consider them for palliative-intent treatment. A group of patients with limited spread (infra-notch) has potential for good outcome. These cancers can be considered for downstaging to T4a classification based on best available data and clinical considerations. The radical surgical resection remains the mainstay of curative-intent treatment and the ability to achieve negative margins at the skull base remains the most important prognostic factor. The alternative approaches to either increase radicality of surgery or to downsize the tumor with neoadjuvant therapies have shown encouraging trends but larger, well designed, and prospective studies will be needed to make meaningful conclusions. It is important to rationalize and form common ground for further research.

Objective: To discuss the surgical technique and outcome of nasal skull base schwannoma treated under endonasal endoscope. Methods: Fifty-two patients with nasal skull base nonvestibular schwannoma were treated under endonasal endoscope from May 2006 to June 2017 in Shanghai E&ENT Hospital. Of the patients, there were 21 men and 31 women. The age of the patients ranged from 33 to 71 years.Schwannoma mainly came from trigeminal nerve.Clinical symptoms included facial numbness, facial pain, nasal obstruction, headache, hypopsia, diplopia and tinnitus. Surgical approaches included pure endonasal endoscope approach (18 cases) and endoscopic endonasal resection asissted with sublabial transmaxillary approach (34 cases). Results: Total tumor resection was achieved in 42 patients(80.8%), subtotal resection in 8 patients, and partial resection in 2 patients. The relief rate of facial numbness, facial pain, nasal obstruction, headache, hypopsia, diplopia and tinnitus were 68.8%, 45.5%, 100.0%, 90.0%, 60.0%, 40.0% and 100.0%, respectively. During surgery, cerebrospinal fluid leakage was observed in 5 cases. All cases were successfully repaired with a nasoseptal flap or autologous fascia lata and fat obtained from thigh. Four cases with recurrence were observed in the follow-up period (6-134 months). Conclusion: Endonasal endoscopic approach is a safe and feasible procedure for schwannoma in nasal cavity, paranasal sinus, orbital apex, pterygopalatine fossa, infratomporal fossa, cavernous sinus and Meckel cave.
目的： 探讨鼻内镜下切除鼻颅底神经鞘瘤的手术经验及效果。 方法： 回顾性分析2006年5月至2017年6月复旦大学附属眼耳鼻喉科医院收治的52例鼻颅底神经鞘瘤患者的临床资料。其中男性21例，女性31例，年龄33～71岁。肿瘤来源以三叉神经为主，临床症状包括面部麻木、面部疼痛、鼻塞、头痛、视力减退、复视、耳鸣。手术方式包括单纯经鼻内镜切除(18例)和鼻内镜联合上颌窦前壁开窗入路(34例)。 结果： 52例患者中，42例行肿瘤全切术(80.8%)，8例因肿瘤涉及重要血管或神经行次全切除术，2例患者因肿瘤部分位于后颅窝而行部分切除术。术后患者的面部麻木、面部疼痛、鼻塞、头痛、视力减退、复视及耳鸣症状缓解率分别为68.8%、45.5%、100.0%、90.0%、60.0%、40.0%和100.0%。术中发生脑脊液鼻漏5例，使用鼻中隔黏膜瓣、鼻甲黏膜或阔筋膜修补完好。术后随访6～134个月，4例肿瘤残余者病变发生进展。 结论： 鼻内镜手术可用于治疗鼻腔、鼻窦、眶尖、翼腭窝、颞下窝、海绵窦或Meckel腔的神经鞘瘤，具有创伤小、恢复快的优势。.