Trigeminal Neuralgia Associated with Achondroplasia. Case Report with Literature Review

Summary  A 59-year-old male with a history of 2 years of typical trigeminal neuralgia manifested the characteristics of achondroplasia. X-ray and magnetic resonance imaging demonstrated basilar impression, deformity of the posterior fossa with marked asymmetry of petrous bone and compression of pons and trigeminal nerve by the left vertebral artery and anterior inferior cerebellar artery. Microvascular decompression was performed through a suboccipital craniectomy. The neuralgia disappeared soon after surgery and remains completely resolved until today. This is the first reported case of trigeminal neuralgia in a patient with achondroplasia. The deformity of the skull base was considered to influence the development of the trigeminal neuralgia.     

Frequency of Diplopia after Intraoperative Nerve Disturbance in Trochlear Nerve Schwannoma: A Case Report and Systematic Review

Schwannomas of the trochlear nerve are relatively rare, and most patients present with preoperative diplopia because of trochlear nerve palsy. We describe the case of a 61-year-old male patient with a trochlear nerve schwannoma and no pre- and postoperative diplopia, despite his trochlear nerve being cut during the operation. We aimed to investigate the frequency of postoperative diplopia associated with intraoperative trochlear nerve disturbance by reviewing previous case reports, wherein postoperative diplopia did not occur after the trochlear nerve was cut intraoperatively. We recorded the frequency of diplopia because of intraoperative trochlear nerve disturbance, such as the trochlear nerve being cut, in cases without pre- and postoperative diplopia. We searched the PubMed, Medline, and Google Scholar databases for works published from 1976 to 2020 and followed the preferred reporting items for systematic reviews and meta-analyses guidelines. We reviewed 36 publications and found 92 cases of trochlear nerve schwannoma. Surgical resection was performed for 43 patients, of whom 40 were kept under observation and 9 were treated with radiation therapy. Of the 43 cases, 9 without preoperative diplopia underwent gross total resection. We analyzed ten cases (including ours) without preoperative diplopia to check for postoperative diplopia. In total, four cases, including ours, did not display postoperative diplopia despite the trochlear nerve being cut. This may be attributed to the preoperatively acquired motor and sensory fusion in the patient’s vision because of tumor progression. Our findings may benefit neurosurgeons who treat patients with schwannomas and help them predict patients’ outcomes.     

Oculomotor Nerve Schwannoma Associated with Acute Hydrocephalus: Case Report

A 37-year-old woman presented with an extremely rare large oculomotor schwannoma associated with acute hydrocephalus manifesting as semicoma and anisocoria. Brain computed tomography and magnetic resonance imaging revealed a tumor in the oculomotor cistern. Cerebral angiography revealed separation of the posterior cerebral artery (PCA) and superior cerebellar artery (SCA). The tumor was removed subtotally by two stage surgery. Histological examination revealed ordinary schwannoma. The diagnosis of oculomotor nerve schwannoma was based on the intraoperative finding of the tumor origin in the oculomotor nerve. Oculomotor nerve schwannoma can cause acute hydrocephalus and manifest as impaired consciousness. The angiographical separation of the PCA and SCA was very useful for the preoperative diagnosis of oculomotor nerve schwannoma.     

Recurrent Lumbosacral Metastases from Intracranial Meningioma. Report of a Case and Review of the Literature

We report a case of a 31 year-old woman who in 1991 presented a clinical history of headaches, nausea and vomiting. CT scan showed a right frontotemporal meningioma. The first operation achieved a macroscopically complete resection. The tumour was histologically classified as a transitional meningioma. There were recurrences of the intracranial meningioma in 1994, 1996, 1997 and 1998. These recurrences were accompanied by differentiation to atypical and anaplastic meningioma. In all of these operations, a macroscopically complete resection of the tumour was performed. In 1996 adjuvant radiation therapy was given. In 1998 therapy with bromocriptine was adopted. In April 1999, the patient presented with lumbosacral pain associated with L5 bilateral sciatica. MRI showed a gadolinium enhancing mass lesion at L5-S1 level. Complete tumour resection was performed. The histological findings were the same as in 1998. In December 1999 the patient presented with perineal pain and MRI showed a L4 and S3 recurrence and the tumour was resected. The histological findings were those of a malignant meningioma. In February 2000 an intracranial recurrence was detected and operated on. The histological diagnosis was malignant meningioma. A review of the literature was undertake and is discussed.     

Ankle Neurothekeoma: A Case Report

Neurothekeoma is a rare, benign, cutaneous tumor of nerve sheath origin that is also termed benign nerve sheath myxoma. This tumor is usually asymptomatic and grows slowly. Neurothekeoma is typically found in young adults and seldom occurs in children. It is most commonly located in the head, neck, and upper extremity and extremely rarely found in the lower leg. We report a rare case of ankle neurothekeoma in a child, with a review of the related published data.     

Prediction of Facial Nerve Displacement in Extralarge Vestibular Schwannoma

Summary  The primary objective in the surgery of extra large vestibular schwannoma is the total removal of the tumour mass while preserving the facial nerve. Preservation of the facial nerve in extra large tumours is reported as being notoriously difficult in the majority of cases  This study was undertaken to evaluate the accuracy in predicting displacement of the facial nerve by preoperative radiological imaging studies in 19 cases of extra large vestibular schwannoma. The direction of displacement of the facial nerve was predicted with preoperative axial and coronal MRI scans and verified intra-operatively.  We achieved total removal of tumours in 84.2%, facial nerve displacement was predicted in 80% and we accomplished anatomical preservation in 80%. Prediction of displacement was difficult in tumours with little or no intracanalicular components or with severe bony destruction of the internal acoustic meatus.  The preoperative prediction of facial nerve displacement in extra large tumours allows safe internal decompression of the tumour and careful dissection near the predicted area of the facial nerve during the operation. Consequently, a high rate of anatomical preservation of the facial nerve can be achieved.     

Giant Ancient Schwannoma of the Posterior Mediastinum Cytologically Misdiagnosed as a Malignant Tumour. A Case Report

We report a case of a 45-year old woman who was found to have a giant mediastinal tumour with radiological degenerative changes. She underwent thoracotomy to remove the mass, which was eventually diagnosed histolo-gically as an ancient schwannoma, whereas cytological interpretation of the accompanying pleural fluid was malignant. Ancient schwannoma is a rare variant of schwannoma, histologically showing atypical features that may result in erroneous diagnosis of a malignant tumour. Clinical and radiological findings are important aids for further consideration of surgical removal of these potentially resectable tumours.     

Solitary Schwannoma of the Colon: Report of Two Cases

Some patients with gastrointestinal schwannoma (GIS) have been previously reported in the literature. However, GIS of the colon is quite rare. In addition, it is sometimes difficult to differentiate neurogenic tumors from other soft tissue tumors. We herein describe two cases of schwannoma of the colon, while also reviewing the relevant Japanese literature. The first case, a 73-year-old woman underwent a sigmoidectomy with lymph node dissection following the diagnosis of submucosal tumor. In the second case, a submucosal tumor was located in the cecum of a 44-year-old man. An endoscopic tumor resection was performed in the second case. The resected tumors measured 3.6 and 1.0 cm in maximal diameter, respectively. Microscopically, the tumors consisted predominantly of spindle-shaped cells that proliferated in an interlaced fashion. Mitosis was rarely seen in these tumors. Immunohistochemically, the tumor cells were strongly positive for S-100 protein, weakly positive for glial fibrillary acidic protein, and negative for CD34, α-smooth-muscle actin, and cytokeratin (CAM 5.2) in both cases. The tumors in the two cases were both diagnosed to be benign schwannoma of the colon. In general, schwannoma of the gastrointestinal tract is considered to be benign and should therefore be distinguished from other spindle-cell tumors or malignancies. Once diagnosed as schwannoma, extensive surgery should be avoided. Actually, such patients tend to show a good postoperative course with no evidence of recurrence. Received: November 2, 2000 / Accepted: May 15, 2001     

Unusual Clinical Presentation of a Meningeal Melanocytoma with Seizures: Case Report and Review of the Literature

Summary  The 17th case of an intracranial meningeal melanocytoma is presented in a 67-year old man. It is the 6th melanocytoma arising from the cavum Meckeli and the first presenting with seizures. Surgical removal was curative for a follow up period of 32 months. Besides the clinical and neuroradiological presentation, the histological, ultrastructural and immunohistochemical features are described. A review of the literature including cases with malignant transformation is given and differential diagnostic problems are discussed.     

Schwannoma of upper eyelid: A rare differential diagnosis of eyelid swellings

Schwannoma is a relatively rare benign tumour of peripheral nerve origin. The occurrence of Schwannoma in eyelid is extremely rare. As per our knowledge, only 11 such cases have been reported in the literature so far. We present a case of a 40-year-old man who presented to us with a 2-year history of slowly enlarging, painless mass in his left upper lid with resultant progressive ptosis. Ocular examination was suggestive of a firm, non-tender nodule of size 2 × 1.5 × 1 cm on the left upper lid. The mass was non-adherent to the skin or the underlying tissue. The eyelid skin and conjunctiva were indurated and signs of inflammation were present. The lateral part of eyelid showed presence of an ulcer and the lid function was severely hampered. Provisional clinical diagnosis was that of an eyelid malignancy. With this in mind, the medial part of the lid was excised and reconstructed using a tarso-conjunctival flap from the lower eyelid in conjunction with a skin graft. The histopathology and immunohistochemistry established the diagnosis of Schwannoma. We recommend that Schwannoma be considered in the differential diagnosis of well-circumscribed eyelid swellings.     

Schwannoma of the Urinary Bladder: A Case Report

The urinary bladder is an extremely rare site for primary schwannomas. They are most often associated with von Recklinghausen disease. This patient was found to have a schwannoma of the bladder in the absence of evidence of von Recklinghausen disease and was successfully treated with a partial cystectomy. This represents only the third such case in the literature of this entity.     

Intraoperative Facial Nerve Monitoring (IFNM) Predicts Facial Nerve Outcome after Resection of Vestibular Schwannoma

Summary Intraoperative facial nerve monitoring (IFNM) is a suitable technique for intraoperative facial nerve identification and dissection, especially in large vestibular schwannomas (VS) (acoustic neuroma). To evaluate its feasibility for estimating functional nerve outcome after VS resection 60 patients underwent surgery using IFNM. Out of this group the last 40 patients were included in a prospective study evaluating the prognostic value of various IFNM parameters (proximal and distal absolute EMG amplitude, stimulation threshold, and proximal-to-distal amplitude ratio) for prediction of initial postoperative facial nerve function and recovery of function. Stimulation threshold and absolute EMG amplitude proximally at the brain stem were both predictive for postoperative nerve function. Good initial facial nerve outcome (modified House Brackmann grading, mHB°I and °II) was found in 15/16 patients with a proximal EMG amplitude greater than 800 μV and in 19/22 patients with proximal stimulation threshold less than 0.3 mA. Sixteen of 16 patients with proximal stimulation threshold equal to or greater than 0.3 mA had moderate-to-severe facial palsy (mHB°III or worse). Six of six patients without evokable proximal amplitude initially had insufficient nerve function (mHB°IV). Intraoperative decrease of the proximal amplitude was associated with an unfavourable outcome, whereas distal amplitudes usually stayed unchanged. Mean distal EMG amplitudes were also found to be decreased with poor nerve function, which may mean that the tumour had already affected the nerve. A proximal amplitude of 300 μV or less and a proximal-to-distal amplitude ratio below 1:3 were found in the absence of functional recovery in 6/8 (75%) and 5/6 (83%) patients with initial mHB°IV, respectively. Two patients with initial mHB°IV improved to mHB°III despite intraoperative evidence of missing functional nerve integrity. Therefore, functional recovery cannot be predicted by IFNM in all cases of anatomical nerve preservation. We conclude that a minimum follow-up period of 1 year may still be advisable even in certain patients without evidence of intraoperative functional nerve integrity.     

Trigeminal Neuralgia Caused by Nerve Compression by Dilated Superior Cerebellar Artery Associated with Cerebellar Arteriovenous Malformation: Case Report

Intracranial arteriovenous malformation (AVM) is a rare cause of trigeminal neuralgia (TGN). In this presented case, successful resolution of AVM-related TGN following embolization and gamma knife radiosurgery (GKRS) was obtained. A patient suffered from TGN on the left side, which was thought to be caused by root entry zone compression by dilated superior cerebellar artery (SCA) associated with cerebellar AVM. The cerebellar vermis AVM was embolized in endovascular surgery. The AVM was reduced in size and TGN was partially relieved. The patient subsequently underwent GKRS for the residual nidus. TGN was completely resolved within one year and a half. GKRS following embolization of the nidus improved the flow-related dilation of the SCA and completely relieved TGN.     

周围神经损伤后S-100蛋白的分布和变化研究

目的：研究周围神经中s-100蛋白的分布及周围神经损伤后s-100蛋白的分布变化及时相改变。探索其与神经再生过程的关系。方法：通过免疫组织化学技术观察大鼠坐骨神经切断后不同是时期神经组织中s-100蛋白的分布变化。结果：在未损伤的神经中，s-100蛋白分布于雪旺细胞的胞浆和胞膜中。神经切断84h后，远近节段均出现s-100蛋白免疫反应表达减弱，远侧段1周后几乎没有s-100蛋白的表达，而近侧段在新生轴索生长时重新表达s-100蛋白。结论：轴索对于雪旺细胞的成熟具有重要的作用，s-100蛋白对于轴索的再生具有刺激和诱导作用。s-100蛋白在周围神经中只存在于成熟的雪旺细胞。s-100蛋白的出现予示着雪旺细胞的成熟和神经再生的表现。     

Oculomotor Nerve Neurinoma: Report of two Cases

Summary  Being motor nerves neurinomas originating from ocular nerves are very rare, unless associated with neurofibromatosis. Authors describe two cases of oculomotor nerve i.e. third nerve, Schwann cell tumours. One of them presented as a cavernous sinus mass in a middle aged lady while the other was a middle aged man with a large cisterno-cavernous tumour. Surgical approach is discussed and the relevant literature reviewed.     

Benign Schwannoma of the Esophagus Removed by Enucleation: Report of a Case

(Received for publication on Sept. 18, 1998; accepted on July 13, 1999)     

Primary Malignant Fibrous Histiocytoma of the Lung A Case Report

A case of malignant fibrous histiocytoma of the lung is presented and the literature concerning this rare tumour is reveiwed. The advisability of postoperative chemotherapy in these cases remains to be clarified and further data are required to establish the optimum management.