• Journal of Korean Neurosurgical Society
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• v.48 no.2
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• pp.173-176
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• 2010

In this report, we introduce an undetermined fibrous tumor with calcification occurring in the cerebellopontine angle (CPA). A 51-year-old woman was admitted with a short history of dizziness. Computed tomography and magnetic resonance images revealed a $2{\times}2{\times}2\;cm$ sized mass at the left CPA which was round and calcified. There was no dura or internal auditory canal involvement. At surgery, the tumor was located at the exit of 7th and 8th cranial nerve complex. It was very firm, bright yellow and well encapsulated. Histologic findings revealed that the tumor was predominantly composed of fibrous component, scant spindle cells and dystrophic calcification. Immunohistochemical staining demonstrated positive for vimentin and negative for epithelial membrane antigen (EMA), S-100 protein, CD34, factor XIIIa and smooth muscle actin. The diagnosis was not compatible with meningioma, schwannoma, metastatic brain tumors, and other fibrous tumors. Although the tumor was resected in total, long term follow-up monitoring is necessary due to the possibility of recurrence.

• Journal of Korean Neurosurgical Society
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• v.47 no.4
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• pp.271-277
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• 2010

Objective : The purpose of this study is to evaluate the clinical characteristics and surgical outcome of cerebellopontine angle (CPA) epidermoids presenting with trigeminal neuralgia. Methods : Between 1996 and 2004, 10 patients with typical symptoms of trigeminal neuralgia were found to have cerebellopontine angle epidermoids and treated surgically at our hospital. We retrospectively analyzed the clinico-radiological records of the patients. Results : Total resection was done in 6 patients (60%). Surgical removal of tumor and microvascular decompression of the trigeminal nerve were performed simultaneously in one case. One patient died due to postoperative aseptic meningitis. The others showed total relief from pain. During follow-up, no patients experienced recurrence of their trigeminal neuralgia (TN). Conclusion : The clinical features of TN from CPA epidermoids are characterized by symptom onset at a younger age compared to TN from vascular causes. In addition to removal of the tumor, the possibility of vascular compression at the root entry zone of the trigeminal nerve should be kept in mind. If it exists, a microvascular decompression (MVD) should be performed. Recurrence of tumor is rare in both total and subtotal removal cases, but long-term follow-up is required.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.30-36
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• 2001

Objective : To investigate the postoperative result and prognostic factors in cerebellopontine meningioma. Materials & Methods : During the years 1990 through 1999, a retrospective study of 17 cerebellopontine angle meningiomas was performed. The retromastoid approach was used in all cases : 14 tumors were excised totally and 3 tumors subtotally. Results : Fourteen patents were females with a median age of 58.7 years. The most common presenting complaints were 8th cranial nerve dysfunction and headache. Most of the tumors were large(>4cm) and extended into the tentorial regions. Histological examination revealed benign meningiomas in 16 patients and atypical in one patient. Tumors were located posterior to the internal auditory meatus in 11 cases and anterior in three cases with three cases of en-plaque type. Two of three patients whose tumors were subtotally excised received radiation therapy. Tumor has recurred in one patient. Postoperative result was good in 16 cases with one mortality case. Conclusion : This results suggest that site of 7th-8th cranial nerves complex, en-plaque type meningioma, and petroclival meningioma extended into the clivus were significant prognostic factors. Postoperative radiation therapy is recommended for cases of subtotal resection.

• Investigative Magnetic Resonance Imaging
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• v.24 no.1
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• pp.38-45
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• 2020

Background: Differentiation of cerebellopontine angle (CPA) schwannoma from meningioma is often a difficult process to identify. Purpose: To identify imaging features for distinguishing CPA schwannoma from meningioma and to investigate the usefulness of susceptibility-weighted imaging (SWI) in differentiating them. Materials and Methods: Between March 2010 and January 2015, this study pathologically confirmed 11 meningiomas and 20 schwannomas involving CPA with preoperative SWI were retrospectively reviewed. Generally, the following MRI features were evaluated: 1) maximal diameter on axial image, 2) angle between tumor border and adjacent petrous bone, 3) presence of intratumoral dark signal intensity on SWI, 4) tumor consistency, 5) blood-fluid level, 6) involvement of internal auditory canal (IAC), 7) dural tail, and 8) involvement of adjacent intracranial space. On CT, 1) presence of dilatation of IAC, 2) intratumoral calcification, and 3) adjacent hyperostosis were evaluated. All features were compared using Chi-squared tests and Fisher's exact tests. The univariate and multivariate logistic regression analysis were performed to identify imaging features that differentiate both tumors. Results: The results noted that schwannomas more frequently demonstrated dark spots on SWI (P = 0.025), cystic consistency (P = 0.034), and globular angle (P = 0.008); schwannomas showed more dilatation of internal auditory meatus and lack of calcification (P = 0.008 and P = 0.02, respectively). However, it was shown that dural tail was more common in meningiomas (P < 0.007). In general, dark spots on SWI and dural tail remained significant in multivariate analysis (P = 0.037 and P = 0.012, respectively). In this case, the combination of two features showed a sensitivity and specificity of 80% and 100% respectively, with an area under the receiver operating characteristic curve of 0.9. Conclusion: In conclusion, dark spots on SWI were found to be helpful in differentiating CPA schwannoma from meningioma. It is noted that combining dural tail with dark spots on SWI yielded strong diagnostic value in differentiating both tumors.

• Journal of Korean Neurosurgical Society
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• v.45 no.3
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• pp.196-198
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• 2009

Hemifacial spasm (HFS) is almost always induced by vascular compression but in some cases the cause of HFS are tumors at cerebellopontine angle (CPA) or vascular malformations. We present a rare case of hemifacial spasm caused by epidermoid tumors and the possible pathogenesis of HFS is discussed. A 36-year-old female patient presented with a 27-month history of progressive involuntary facial twitching and had been treated with acupuncture and herb medication. On imaging study, a mass lesion was seen at right CPA. Microvascular decompression combined with mass removal was undertaken through retrosigmoid approach. The lesion was avascular mass and diagnosed with an epidermoid tumor pathologically. Eventually, we found a offending vessel (AICA : anterior inferior cerebellar artery) compressing facial nerve root exit zone (REZ). In case of HFS caused by tumor compression on the facial nerve REZ, surgeons should try to find an offending vessel under the mass. This case supports the vascular compression theory as a pathogenesis of HFS.

• Journal of Korean Neurosurgical Society
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• v.41 no.1
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• pp.39-42
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• 2007

Primary intracranial melanoma is uncommon. These tumors most commonly occur at the temporal lobe, cerebellum and cerebellopontine angle. We report a case of intracranial malignant melanoma of the occipital lobe in a 60-year-old man who presented with headache and visual disturbance. The mass showed hyperintensity on T1-weighted images and hypointensity on T2-weighted magnetic resonance images. He underwent gross total removal of tumor and received radiotherapy. Follow-up imaging studios showed neither recurrence nor any signs of residual disease for 4 months.

• Journal of Korean Neurosurgical Society
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• v.41 no.5
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• pp.330-332
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• 2007

Intracranial lipomas are rare, and most of these tumors are found in the region of the corpus callosum, followed by cerebellopontine angle. We present a case of a intracranial lipoma in 30-year-old man. Brain computed tomography [CT] scan and magnetic resonance images [MRI] showed a mass in the medulla oblongata extending to foramen magnum. The histopathologically, diagnosis of lipoma was confirmed. Although there were several cases of cervical intraspinal lipoma extending into posterior cranial fossa, there have been no previous reports of a lipoma arising from the medulla oblongata that extended into the foramen magnum. We describe a rare case of intradural subpial lipoma in the medulla oblongata with a review of the literature.

• The Korean Journal of Cytopathology
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• v.15 no.1
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• pp.52-55
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• 2004

Secretory meningioma is a distinct subtype of meningioma. We describe the cytologic features of a secretory meningioma on squash preparations, in comparision with other cytologic mimickers. A 54-year-old woman presented with hearing loss, vertigo, tinnitus, and headache for seven years. A brain MRI study revealed a 4.5cm sized mass in the cerebellopontine angle, which showed homogenous signal intensity in T2-weighted image. The intraoperative squash smear showed some well-defined, thin rimmed intracytoplasmic inclusions, containing a finely granular eosinophilic core among less cohesive meningiomatous cells. Histologic sections revealed a meningothelial meningioma with scattered inclusions, with periodic acid-Schiff, carcinoembryonic antigen, and cytokeratin positivity. Identification of characteristic intracytoplasmic inclusions is helpful for diagnosing secretory meningiomas. On squash preparations, differential diagnoses included tumors with inclusions or cytoplasmic vacuolizations, such as metastatic mammary infiltrating ductal carcinoma, gastric adenocarcinoma, hepatocellular carcinoma, and clear cell ependymoma, oligodendroglioma, hemangioblastoma, chordoma, and other variants of meningiomas (clear cell, xanthomatous, microcytic, and chordoid variants). In addition, the possibilities of glioma with eosinophilic granular body, and metastatic tumors from mammary infiltrating ductal carcinoma, gastric adenocarcinoma, and hepatocellular carcinoma in meningioma should be considered.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1437-1444
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• 2000

Objectives : Traditionally intracranial meningiomas are regarded as benign and curable tumors. About half of all intracranial meningiomas locate in the skull base region. However, surgical removal of these tumors may be challenging and require special considerations. Here general aspects of skull base meningiomas including clinical presentation, surgical approaches, complications and their recurrence rate are discussed based on our experiences. Methods : A retrospective analysis of 61 consecutive patients with skull base meningioma among 210 patients of meningioma between 1989 and 1998 were done. Results : There were 41 women and 20 men ranging from 13 to 74 years(mean 52 years). These tumors were divided into seven categories according to location : olfactory groove(n＝9), sphenoid ridge(n＝16), cavernous sinus(n ＝2), tuberculum sellae(n＝8), tentorium(n＝13), cerebellopontine angle(n＝12), and foramen magnum meningiomas (n＝1). Surgical approaches were selected on the basis of the tumor attachment, size and extension on preoperative radiologic findings. Total removal(Simpson grade I and II) was achieved in 50 cases(82%), and subtotal removal (Simpson grade III) in 11 patients(18%). According to WHO classification, there were 52 of cases of benign meningioma( 86%), 6 atypical cases(10%), and 3 malignant cases(5%). The most common postoperative complications were CSF leakage(23.0%) and cranial nerve injury(8.2%). Three patient died related with tumor(one was due to surgical complication and the other two due to recurrence) but three patients died from other systemic causes. Mean follow-up period was 51.7 months after surgery. Recurrence occurred in six patients(10.9%) ; three with tentorial meningioma, two with sphenoid ridge, and one in cerebellopontine angle. Conclusion : With advances in neuroradiology and microsurgical techniques, the surgical outcome of miningiomas has been markedly improved with acceptable morbidity and mortality rates. Overall, our surgical results of skull base meningiomas is comparable to other reports. Therefore, with the appropriate operative strategy and techniques, these tumors can be completely removed and good surgical results can be expected.

• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.744-747
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• 2000

Objectives : The purpose of this study was to evaluate the clinical features of the epidermoid tumor of posterior fossa and to assess the surgical outcome. Methods : We reviewed the clinicoradiological records of 10 epidermoid tumor of posterior fossa, treated surgically at our hospital between 1991 and 1996. Results : The mean age of onset was 36 years old and mean duration of symptom was 5.2 years. Six were men and four were women. The location of tumors were cerebellopontine angle(CPA) 5 cases, cerebellum(Cbll)& 4th ventricle 3 cases, foramen magnum 1 case, and pineal region extended to Cbll and 4th ventricle 1 case. Common clinical features were trigeminal neuralgia in 3 cases, cerebellar signs 2 case, headache 2 cases, hemifacial spasm with deafness 1 case, cbll signs and multiple cranial nerve dysfunctions 1 case. One CPA epidermoid had no clinical symptom and sign associated with the tumor. The surgical approaches were suboccipital approach in 9 cases and one transcallosal approach to the tumor of pineal region. The extent of surgical removal was gross total resection in 5 cases and near total or subtotal resection in 5. Two patients with CPA tumor were complicated with facial paresis. One patient with tumor located in cerebellum extended into cisterna magna had postoperative vocal cord paresis. All complicated cases had severe adhesion of tumor capsule with brainstem or cranial nerve. The mean duration of follow up was 26 months. The overall outcome was improvement of symptoms and signs in 6 cases and stationary 4 cases. During follow up, imaging study was done in 7 patients and none of them had finding of tumor recurrence. Conclusion : We conclude that recurrence of tumor is rare in both total and subtotal resected cases, but long-term follow-up is required. Aggressive removal of tumor capsule that adhesed to brianstem or cranial nerve is avoided for preventing severe postoperative complication.