Two cases of the epidermoid on the petrous bone

Epidermoids known as cholesteatomas, are congenital benign tumors and originate in the embryonic ectoderm. They account for 1.3% of all intracranial tumors. They are often found in the cerebellopontine angle and the paraseller region, but rarely in the petrous portion of the temporal bone. Epidermoids of the petrous bone tend to slowly present progressive facial palsy and hearing disturbance. In this article, two cases of epidermoids involving the petrous bone are reported. A 55-year-old male presented left facial palsy, left hearing disturbance and decreased gustation in the left side of the tongue. MRI revealed a non-enhanced mass on the petrous portion of the left temporal bone, and bone-window CT showed bone destruction in the same region (Case 1). A 71-year-old female was aware of left facial palsy and left hearing loss for 15 years. MRI showed a non-enhanced mass on the petrous bone, and bone-window CT demonstrated extensive bone erosion of the petrous bone and the middle cranial fossa (Case 2). In both cases, total removal was performed via the middle cranial fossa approach. Both tumors existed extradurally and had pressed against the genicurate ganglion of the facial nerve. The facial palsy of the former case recovered 12 months after surgery. We discuss the problems of diagnosis and treatment of epidermoids of the petrous bone.     

Cerebellopontine angle epidermoids: results of surgical treatment

Epidermoids, or congenital cholesteatomas, constitute about 0.2% to 1.5% of intracranial tumors, and 3% to 5% of tumors of the cerebellopontine angle (CPA). We review the surgical management of CPA epidermoids in 13 patients at the House Ear Clinic for the years 1978 to 1993. There were seven male and six female patients, ranging in age from 27 to 59 years (average, 40 years). Tumors ranged in size from 3.5 cm to 7.0 cm, and the surgical approach was tailored to the tumor extent and location. All patients complained at presentation of unilateral hearing loss, and nine had poor speech discrimination (less than 50%) preoperatively. Serviceable hearing was preserved in two patients. Two patients presented with facial nerve symptoms, and four cases had postoperative permanent facial nerve paralysis (House-Brackmann Grade V or VI). There were no surgical deaths. Four patients required second surgeries to remove residual cholesteatoma. Compared with prior series, we describe a higher rate of total tumor removed, as well as a higher rate of second operations, indicating a more aggressive approach to these lesions.     

Cerebellopontine Angle Epidermoids: Results of Surgical Treatment

Epidermoids, or congenital cholesteatomas, constitute about 0.2% to 1.5% of intracranial tumors, and 3% to 5% of tumors of the cerebellopontine angle (CPA). We review the surgical management of CPA epidermoids in 13 patients at the House Ear Clinic for the years 1978 to 1993. There were seven male and six female patients, ranging in age from 27 to 59 years (average, 40 years). Tumors ranged in size from 3.5 cm to 7.0 cm, and the surgical approach was tailored to the tumor extent and location. All patients complained at presentation of unilateral hearing loss, and nine had poor speech discrimination (less than 50%) preoperatively. Serviceable hearing was preserved in two patients. Two patients presented with facial nerve symptoms, and four cases had postoperative permanent facial nerve paralysis (House-Brackmann Grade V or VI). There were no surgical deaths. Four patients required second surgeries to remove residual cholesteatoma. Compared with prior series, we describe a higher rate of total tumor removed, as well as a higher rate of second operations, indicating a more aggressive approach to these lesions.     

Cerebellopontine angle epidermoids presenting with cranial nerve hyperactive dysfunction: pathogenesis and long-term surgical results in 30 patients

OBJECTIVE: To provide the characteristics and long-term surgical results of patients who present with cerebellopontine angle epidermoids and trigeminal neuralgia (TN) or hemifacial spasm. METHODS: A total of 30 patients (23 women, 7 men) who presented with cerebellopontine angle epidermoids and TN (28 patients) or hemifacial spasm (2 patients) between 1982 and 1995 were reviewed, with emphasis being placed on the clinical manifestations, the mechanisms of symptom development, the long-term follow-up results, and the anatomic relationship between the tumor and the surrounding neurovascular structures. RESULTS: The average age of the patients was 37.8 years at symptom onset and 49.3 years at the time of the operation. The tumor-nerve relationships were classified into four types: complete encasement of the nerve by the tumor, compression and distortion of the nerve by the tumor, compression of the nerve by an artery located on the opposite side of the unilateral tumor, and compression of the nerve by an artery on the same side of the tumor. Total resection was achieved in 17 patients (56.7%). Microvascular decompression of the respective cranial nerve was achieved in nine cases of direct arterial compression in addition to tumor removal. The symptom was relieved completely in all cases. In an average follow-up period of 11.5 years, three patients developed recurrent symptoms: two experienced tumor regrowth, and one had arachnoid adhesion. CONCLUSION: Hyperactive dysfunction of the cranial nerves, especially TN, may be the initial and only symptom that patients with cerebellopontine angle epidermoids experience. The occurrence of TN at a younger age was characteristic of TN patients with epidermoids, in contrast to patients with TN due to a vascular cause. The symptom is elicited by compression of the nerve by the tumor per se, by an artery that is displaced to the nerve, or by both. Careful resection of the tumor, whose capsule occasionally is strongly adherent to the neurovascular structures, is necessary, and microvascular decompression to straighten the neuraxis should be performed in some cases to achieve a complete, permanent cure of symptoms with a low rate of recurrence.     

Pineal epidermoid cysts: a study of 24 cases

BACKGROUND: A retrospective analysis of clinical features and management strategy in 24 cases of epidermoids in the pineal region is done. Long-term outcome of radical surgical resection is analyzed. METHODS: Twenty-four patients having epidermoids in the pineal region were surgically treated in our department during an 11-year period (1992 up to 2003). These cases were retrospectively analyzed. The average duration of follow-up was 5.2 years. RESULTS: The age at the time of presentation ranged from 13 to 51 years (mean, 29.2 years). There were 15 male and 9 female patients. The average duration of complaints was 7 months. Headache and ataxia were the commonest symptoms. The infratentorial-supracerebellar approach and the interhemispheric posterior parietooccipital route were used to excise the epidermoids in 20 and 3 patients, respectively. In one patient, the tumor was removed in 2 stages, first by the infratentorial-supracerebellar approach and subsequently by the interhemispheric posterior parietooccipital surgical approach. Total excision of the solid part of the tumor and the capsule was achieved in 6 patients. In 13 cases, the solid part of the tumor was completely resected, but at least, a part of the tumor capsule was left behind. In 5 cases, a part of the solid portion of the tumor was either deliberately or inadvertently left behind. Incomplete tumor resection was primarily due to adhesions of the capsule to large veins in the region, dissection around which was considered hazardous, and extensive and invasive nature of extension of the tumor. During the period of follow-up, one patient had asymptomatic growth of the residual tumor after 6 years of surgery. One patient with residual tumor continued to get generalized seizures. All patients are leading active lives. CONCLUSION: Radical surgery for pineal region epidermoid tumors is associated with an excellent immediate postoperative and long-term outcome.     

颅后窝胆脂瘤的手术处理

本文报道我院近20年收治的162例颅后窝胆脂癌。男94、女68例，平均年龄41．8(5～73)岁．病程4．5月至18年，平均5．4年。临床主要征象为小脑综合征、眼肌运动障碍、单一或多颅神经麻痹，晚期病例出现颅内压增高症状。根据临床表现及影像学检查作出诊断。奎组均行显微外科手术治行，149例(92％)肿瘤获全切除，余13例(8％)因肿瘤包膜与脑干粘连紧密而行次全切除。手术结果：158例治愈(97．5％)，4例于手术后2周内因脑干缺血、水肿或肺部感染死亡(2．5％)。文中对本病的诊断与手术处理原则进行了讨论。     

影响小脑幕及窦汇区脑膜瘤显微手术全切除的因素

目的：评价影响小脑幕及窦汇区脑膜瘤显微手术全切除的因素。方法：回顾分析经显微手术治疗的小脑幕及窦汇区脑膜瘤23例的临床资料及复述相关文献。结果：手术全切除肿瘤17例,次全切除6例。在次全切除的6例中,4例与颅内大静脉窦受肿瘤侵蚀,且存在静脉回流代偿不完全有关,2例同脑干,血管及脑神经与肿瘤粘连紧密或受肿瘤侵犯有关。结论：影响小脑幕及窦汇区脑膜瘤显微外科手术全切除的主要因素是颅内大静脉窦受侵犯及静脉的回流代偿不完全,肿瘤与脑干和脑神经的紧密粘连。     

Posterior cranial fossa arteriovenous malformations]

24 cases of AVMs posterior cranial fossa are reported. All these cases were confirmed by pathological examination or vertebral angiogram. There are 17 cases located in cerebellar hemisphere, 4 in vermis, 2 spread to brain stem, and 1 in fourth ventricle. Most of these patients are young adults, the mean age below 40 years. The most clinical manifestations were acute subarachnoid hemorrhage, increased intracranial pressure, ataxia, and cranial nerves palsy. 22 cases underwent surgical intervention, with 17 total, 3 subtotal, 2 partial resection of AVMs. After operation, 16 cases were good recovery, 3 free of symptom, and 3 death. In this article, the evaluation of some special clinical examinations and the operative approach for AVMs were discussed.     

Meningiomas of the lateral skull base: neurotologic manifestations and patterns of recurrence

The eradication of basicranial meningiomas by traditional surgical techniques is often hindered by neoplastic entanglement with critical neurovascular structures. Apparent, complete tumor resection is frequently followed by extensive, yet clinically silent, recurrent disease with local infiltration of bone, cranial nerves, and brain. Fifty-five cases of sphenoid wing or parasellar meningioma were analyzed to identify clinical manifestations suggestive of early tumor recurrence. Regrowth patterns were then defined according to preoperative radiographic and intraoperative surgical findings. Medial tumor regrowth, involving the cavernous sinus, caused neurapraxia of cranial nerves III, IV, or VI, with associated diplopia or ophthalmoplegia. Inferior (caudal) regrowth of disease involved the infratemporal fossa, pterygomaxillary space, or paranasal sinuses by bony erosion of the middle cranial fossa floor or through natural anatomic foramina and fissures. Such inferior extension was manifested clinically by facial hypesthesia, trismus, and referred otalgia caused by trigeminal nerve involvement and by autophony or serous otitis media related to eustachian tube obstruction. Posterior tumor regrowth occurred along the petrous bone and horizontal carotid canal, resulting in internal auditory meatus erosion and cerebellopontine angle extension with associated tinnitus, hearing loss, unsteadiness, and occasional facial twitching. While the clinical and radiographic evaluations of any patient with a suspected recurrent basicranial meningioma are critical in planning the method and magnitude of reoperation, an understanding of potential recurrence patterns can be used in devising more extensive, combined approaches that may allow complete tumor extirpation at the initial surgical intervention.     

Magnetic resonance imaging of vertebrobasilar ectasia in tic convulsif. Case report

A patient with trigeminal neuralgia and hemifacial spasm was evaluated using multiplanar magnetic resonance (MR) imaging with gadolinium enhancement. Preoperative images demonstrated massively ectatic vertebral and basilar arteries and their distortion of the brain stem and the trigeminal and facial nerves. Surgical manipulation included selective trigeminal rhizotomy, cushioning of the residual nerve at the point of maximal distortion by the underlying basilar artery, and microvascular decompression of the seventh nerve from the anterior inferior cerebellar artery which was being pushed dorsomedially by the vertebral artery. Postoperatively, the patient had neither trigeminal neuralgia nor facial spasm. Gadolinium-enhanced MR imaging not only excludes other etiologies such as tumor or arteriovenous malformation, but also demonstrates cranial nerve compression by ectatic vertebral and basilar arteries. The choice of preoperative imaging modality is discussed and the literature concerning the etiology of tic convulsif is reviewed.     

Brain stem tuberculosis in children

Tubercular meningitis and intracranial tuberculomas are the two frequent manifestations of neurotuberculosis with their variable incidence in different countries. Brain stem tuberculomas are even more unusual, accounting for 2.5-8% of all intracranial tuberculomas. We present here six paediatric cases of brain stem tuberculosis, where well-formed tuberculomas were demonstrated in five symptomatic cases; however, only a hypodense ill-defined lesion was found in the brain stem of one child who presented with features of tubercular meningitis. Three of these children had other associated tuberculomas in their brain parenchyma as well. All the six cases, however, showed the involvement of 3rd, 6th & 7th cranial nerves, in various combinations, at the time of initial presentation. Only two children developed hydrocephalus and required CSF diversion. All responded well to anti-tubercular chemotherapy, though two children developed toxicity to the therapy, which recovered with drug manipulation for about 2 months. Recovery was full without residual deficit in all the cases. Surgical excision of brain stem granulomas was not indicated in any case.     

Cerebellopontine Angle Lipoma: Case Report and Review of the Literature

Intracranial lipomas located in the cerebellopontine angle are extremely rare. These tumours are mal-developmental lesions which can cause slowly progressive neurological symptoms. The clinical management of these tumours differs significantly from other lesions in this region. A 27 year old woman presented with a 2-month history of vertigo and a slowly progressive deterioration of hearing in the left ear. Computed tomography (CT) revealed a large low-density mass in the left cerebellopontine angle without any contrast-enhancement. In T1-weighted magnetic resonance imaging (MRI) the lesion was hyper-intense and did not enhance after application of gadolinium. Areas of lower signal intensity inside of the lesion were suggested as incorporated cranial nerves. A left retro-sigmoidal approach in a semi-sitting position was chosen to expose the tumour. After reducing the tumour mass, the tumour was dissected from the cranial nerves which were incorporated into the tumour. The residual tumour was adherent to the brain stem and the encased lower cranial nerves, allowing only a near subtotal resection of the highly vascularized tumour in order to avoid neurological deficits. The histological examination revealed a lipoma. Attempts at complete removal of cerebellopontine angle lipomas usually result in severe neurological deficits. Conservative treatment should therefore be preferred. Limited surgery is indicated if the patients suffer from disabling neurological symptoms and signs e.g., vertigo, nausea, trigeminal neuralgia, facial weakness or facial spasm.     

Intra-axial dermoid/epidermoid tumors of the brainstem in children

BACKGROUND: Epidermoid and dermoid cysts are rare intracranial space-occupying lesions, which account for about 1% of all intracranial tumors; they are even rarer in the pediatric age group. Among the various locations, that inside the brain stem is quite exceptional (only 12 cases reported to date in the literature). We report two additional cases occurring in children, underlining their clinical characteristics, the difficulties faced in the diagnostic work-up, and the surgical treatment adopted (which consisted of removal of the cyst contents and partial resection of the cyst membrane, because of its adherence to the surrounding nervous and vascular structures). METHODS: We report two cases of intraaxial dermoid/epidermoid cysts observed within the last 5 years. Both patients complained of cervico-nuchal pain, with a remittent/intermittent character in one of them; this patient also exhibited transient 6th and 7th cranial nerve deficit. One lesion was approached through the floor of the fourth ventricle, the second one through the ventrolateral aspect of the brainstem. RESULTS: Subtotal tumor resection was achieved in both cases. Both patients had a smooth postoperative course without permanent neurological deficits. In the first patient residual tumor remains stable on follow-up MRI. In the second one, early tumor regrowth necessitated a second operation, after which the residual tumor has remained stable. CONCLUSIONS: Based on our experience we suggest that a cautious surgical approach ("conservative" resection) to these lesions is the best choice. In fact, attempts at radical removal carry unacceptably high morbidity and mortality rates.     

The coexistence of basal epidermoid tumor and trigeminal neurinoma within the posterior fossa

Recently we encountered one case with basal epidermoid tumor originated in the cerebellopontine angle, associated with a trigeminal neurinoma of the Gasserian ganglion and trigeminal root within both middle and posterior fossa. We wish to present the case with an analytical review of the reported cases of multiple intracranial tumors. The patient was a 49-year-old man who noted the onset of left facial nerve palsy in March, 1974, which lasted for several years. In April 1976, he developed unsteadiness of gait which was not worsening. He noted left facial pain and paresthesias of tongue in October, 1981 and was pointed out as having left hearing disturbance by a physician. He was admitted to our hospital on December 11, 1981. Neurological examination showed hypalgesia and hypesthesia on his left face, left VII cranial nerve palsy and left-sided hearing loss. The IX and X cranial nerves were also involved with absent gag reflexes on the left side and swallowing difficulty. Tongue was deviated to the right on protrusion. He had mild ataxia of the left limbs, ataxic gait and horizontal gaze nystagmus to the right. He had neither café-au-lait spot nor subcutaneous tumor suggestive of von Recklinghausen's disease. CT scan revealed water density lesion in the prepontine and cerebellopontine cisterns which seemed to distort brainstem posteriorly. Metrizamide CT cisternography showed a large fungated mass filling the basal cistern. These findings strongly suggested the presence of an epidermoid tumor. A left suboccipital craniectomy was performed on May 13, 1982. A large pearly mass filling the basal cistern was removed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Contralateral trigeminal neuralgia as a false localizing sign in intracranial tumors

Three cases of contralateral trigeminal neuralgia as a false localizing sign in intracranial tumors are reported. In each patient (meningioma, 2 cases; cholesteatoma, 1 case) the tumor was asymptomatic, so that intracranial tumor had not been suspected preoperatively. In all cases, tumors were large and firm. The tumor was supratentorial in two cases. In one case, a cortically mediated mechanism may have caused the neuralgia, whereas in the remaining two cases distortion and displacement of the brain stem and compression of the contralateral Meckel's cave would explain the trigeminal nerve signs.     

Cerebellopontine angle epidermoid cysts: clinical presentations and surgical outcome

Epidermoid cysts constitute less than 1 % of intracranial tumors with the majority of them involving cerebellopontine angle (CPA). Although several mechanisms for cranial nerve dysfunction due to these tumors have been proposed, no direct evaluation for hyper- or hypoactive dysfunction has been done. In this case series, pathophysiology of cranial nerve dysfunction in CPA epidermoid cysts was evaluated with special attention to a new mechanism of capsule strangulation caused by stratified tumor capsule. Twenty-two cases with epidermoid cysts of CPA micro-neurosurgically treated in our departments since 2005 were reviewed. Clinical status of the patients before the surgery and post-operative functional outcome were recorded. Available data from the English literature were summarized for comparison. Mass reduction of cyst contents in most cases was usually associated with prompt and marked improvement of the symptoms suggesting neuroapraxia caused by compression of the tumor content and/or mild ischemia. Among them, two cases showed strangulation of the affected nerves by the tumor capsule whose preoperative dysfunction did not improve after surgery in spite of meticulous microsurgical removal of the lesion. Involved facial and abducent nerves in these two cases showed distortion of nerve axis and nerve atrophy distal to the strangulation site. We report the first direct evidence of etiology of cranial nerve dysfunction caused by cerebellopontine angle epidermoid tumors. Young age and rapidly progressive neurological deficit might be the characteristics for strangulation of the affected nerves by the cyst capsule. Even though the number of cases might be limited, immediate decompression and release of the strangulating band might be urged in such patients to prevent irreversible deficits.     

Endoscope assisted removal of jugular foramen schwannoma; report of 3 cases.

Removal of the intraforaminal portion of a jugular foramen schwannoma under direct vision requires resection of the adjacent bone. Extensive resection of the bone around the jugular foramen, however, involves a potential danger for cerebrospinal fluid (CSF) leakage and for damage to the adjacent cranial nerves as well as venous outflow. To avoid such bone resection, we applied the endoscope during the removal of a jugular foramen schwannoma through the lateral suboccipital approach. Three patients with schwannomas in the jugular foramen were treated using the lateral suboccipital approach with endoscopic assistance. After the intracranial portion was first removed under the microscope, the residual tumor in the jugular foramen was subsequently removed under the side-viewing endoscope. In all cases the tumor was removed successfully without major complications. The authors conclude that if the cases are selected properly, removal of the schwannoma extending into the jugular foramen is feasible through the conventional lateral suboccipital window under endoscopic assistance.     

Intracranial meningeal melanocytoma

A 59-year-old man presented with a rare intracranial meningeal melanocytoma in the left cerebellopontine angle. The patient underwent partial surgical excision and radiosurgery for successful control of the tumor. Meningeal melanocytoma is an essentially benign melanotic tumor, derived from the melanocytes of the leptomeninges, and may occur anywhere in the cranial and spinal meninges. Preoperative differential diagnosis of intracranial meningeal melanocytoma from malignant melanoma is difficult based on magnetic resonance imaging. Ultrastructural findings are essential to establish the diagnosis. The prognosis of this tumor is not always favorable with occasional local recurrence. Total resection is the best treatment, but gamma knife radiosurgery is effective for the residual tumor following partial resection.     

Primary malignant lymphoma of the trigeminal region treated with rapid infusion of high-dose MTX and radiation: case report and review of the literature

BACKGROUND: Extra-axial primary CNS lymphoma, considered rare, mainly arise in the white matter of the brain. Though the tumor responds well to radiation and chemotherapy, the prognosis of primary CNS lymphoma remains poor. We report a case of primary lymphoma of Meckel's cave mimicking a trigeminal schwannoma radiographically, which achieved complete remission through use of rapid high-dose MTX therapy and radiation therapy. CASE DESCRIPTION: The patient, a 55-year-old Japanese male, presented left trigeminal neuralgia. Magnetic resonance imaging (MRI) revealed a mass lesion in the left side of Meckel's cave, with extension into the cerebellopontine angle and the infratemporal fossa through the foramen ovale, suggesting trigeminal schwannoma. However, the patient suffered radiologically inexplicable progressive cranial nerve palsy, which suggested malignant disease. MRI and CSF disclosed malignant tumor dissemination; biopsy revealed malignant lymphoma. The treatment, composed of the rapid infusion of high-dose MTX and whole brain and spine radiation, resulted in complete remission. CONCLUSIONS: This case, which included atypical presentation of malignant lymphoma, illustrates the importance of including malignant lymphoma in the differential diagnosis of CP-angle and Meckel's cave tumor. The results also confirmed the usefulness of combined rapid high-dose MTX therapy and radiation.