[An operative case of cholesterol granuloma of the petrous apex]

A 59-year-old man presented with a rare cholesterol granuloma of the petrous apex manifesting as headache, left facial dysesthesia, diplopia, left hearing impairment, and left tinnitus. Neurological examination revealed dysesthesia of territory in all divisions of the left trigeminal nerve, left incomplete abducens nerve palsy, left mixed hearing impairment, and left tinnitus. Plain CT scan showed a smoothly marginated mass involving the left petrous apex. The mass was isodense with the brain parenchyma and not enhanced by contrast medium. The mass appeared heterogeneously slightly hyperintense on the T1-weighted MR image and homogeneously hyperintense on the T2-weighted MR image except for the peripheral portion. The mass was not enhanced after intravenous gadolinium DTPA administration. Surgery via a petrosal approach totally removed the mass in the intracranial, extradural space. Histological examination showed typical features of cholesterol granuloma, with cholesterin clefts, hemosiderin deposits, and erythrocytes in non-specific granulation tissue. Cholesterol granuloma most commonly occurs in the middle ear cavity, and rarely in the petrous apex. The characteristic hyperintense appearance of cholesterol granuloma on T1- and T2-weighted MR images is very useful for differentiation from other lesions of the petrous apex and the cerebellopontine angle such as cholesteatoma, mucocele, chordoma, and meningioma. Solid cholesterol granuloma of the petrous apex should be treated by total removal via craniotomy, not by drainage which is commonly performed by otorhinologists.

Prognostic value of complete response after the initial treatment for malignant astrocytoma

To evaluate prognostic value of complete disappearance of the tumor mass in contrast enhanced computerized tomography after initial treatment, 81 patients with supratentorial malignant astrocytomas (57 anaplastic astrocytomas and 24 glioblastomas) were divided into two groups. All complete response CR patients received the gross total resection (more than 95% resection). Average age of this group was significantly younger than that of noncomplete response patients (38.4 vs. 49.7 years old, p < 0.05; Student t-test). In the complete response group, median survival duration was 58 months, 2-year survival rate was 77%, and 5-year survival rate was 34% compared to 12 months, 29%, and 10%, respectively, in the noncomplete response group. The outcome of CR group was significantly better (p < 0.001; Wilcoxon test). Therefore, complete response at completion of the initial treatment is an important predictor of longer survival. Gross total resection is essential to obtain complete response and thus plays a crucial role in the initial treatment of malignant astrocytomas.

Expression of heme oxygenase and inducible nitric oxide synthase mRNA in human brain tumors

Heme oxygenase-1, a key enzyme in heme catabolism, and inducible nitric oxide synthase (iNOS) are responsible for production of carbon monoxide and nitric oxide (NO), respectively. Expression of each enzyme has been shown to be modulated by heme and NO, raising a possibility for the coordinated regulation of the two enzymes. We therefore analyzed the expression levels of both mRNA in humans using brain tumors. Either heme oxygenase-1 or iNOS mRNA was expressed at higher levels in brain tumors compared to the brain tissue, but their expression levels were not apparently correlated. In the brain tumor cell lines, treatment with cytokines increased the expression of iNOS mRNA but not heme oxygenase-1 mRNA, whereas treatment with an NO donor increased the expression of heme oxygenase-1 mRNA but not iNOS mRNA. These results suggest the separate regulation of expression of both enzyme mRNA in humans.

Alteration of c-fos gene methylation in human gliomas

In an attempt to find a common DNA alteration occurring in human glioma, we examined DNA methylation in 34 gliomas of various pathological grades and compared them with those in normal cerebral subcortex DNA. The total methylated cytosine levels in the genome did not differ appreciably between the tumors and the normal tissues; however, the degree of DNA methylation in several proto-oncogenes and suppressor oncogenes showed some alterations. Among them, the c-fos gene demonstrated deviation from that of normal tissues in all cases examined, suggesting that the alteration of c-fos gene methylation plays a role in the early steps of human glioma development.

Indirect revascularization for moyamoya disease: is there a beneficial effect for adult patients?

BACKGROUND

It is generally accepted that excellent development of collateral circulation can be achieved through indirect nonanastomotic bypass procedures for pediatric patients with moyamoya disease. However, there are no definitive conclusions about the effect of indirect revascularization for adult patients. To clarify the value of indirect bypass surgery for adult moyamoya disease, we have analyzed their follow-up angiographic results in comparison with those of the pediatric patients.

METHODS

Between 1989 and 1993, 23 patients underwent combined direct and indirect bypass surgery. They consisted of 16 adults (mean age, 35; range, 20-59) and seven children (mean age, 10; range, 3-16). The main symptoms were those due to cerebral ischemia in all but 1 of 23 patients. Preoperative cerebral blood flow studies showed all patients to have decreased vascular reserve (misery perfusion). Postoperative follow-up angiography was done in all patients at a median of 6 months after the surgery.

RESULTS

All pediatric patients showed good or moderate development of collaterals through the indirect bypass. Among the adult group, seven patients aged 20 to 29 had angiographic results similar to those of the pediatric group . On the other hand, nine patients older than 30 had results contrary to those of pediatric patients: (1) the degree of indirect revascularization declined to moderate or poor grades (especially in patients older than 40) and (2) the degree of direct bypass filling improved to high or medium grades.

CONCLUSIONS

The results suggest that advancing age apparently affects the development of collateral formation through the indirect bypass. Consequently, direct bypass is thought to be the main treatment option for patients older than 40.

Noninvasive evaluation of malignancy of brain tumors with proton MR spectroscopy

PURPOSE

To test clinical proton MR spectroscopy as a noninvasive method for predicting tumor malignancy.

METHODS

Water-suppressed single-voxel point resolved spectroscopy in the frontal white matter of 17 healthy volunteers and 25 patients with brain tumors yielded spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cre), and lactate. These peak intensities were semiquantitated as a ratio to that of the external reference. The validity of the semiquantitation was first evaluated through phantom and volunteer experiments.

RESULTS

The variation in measurements of the designated region in the volunteers was less than 10%. Normal ranges of NAA/reference, Cho/reference, and Cre/reference were 3.59 +/- 0.68, 1.96 +/- 0.66, and 1.53 +/- 0.64 (mean +/- SD), respectively. In 17 gliomas, the Cho/reference value in high-grade gliomas was significantly higher than in low-grade gliomas. Levels of NAA/reference were also significantly different in low-grade and high-grade malignancy. In eight meningiomas (four newly diagnosed and four recurrent), the level of Cho/reference was significantly higher in recurrent meningiomas than in normal white matter or in newly diagnosed meningiomas.

CONCLUSIONS

Higher grades of brain tumors in this study were associated with higher Cho/reference and lower NAA/reference values. These results suggest that clinical proton MR spectroscopy may help predict tumor malignancy.

Deletion mapping of chromosome 10 in human glioma

We analyzed DNAs from 35 gliomas (27 malignant, grades III and IV; 8 less malignant, grades I and II) for loss of heterozygosity (LOH) using microsatellite sequences on chromosome 10 as polymorphic markers. An LOH was found in 8 of 11 (73%) glioblastomas (grade IV) and 4 of 16 (25%) grade III gliomas, but not in the less malignant types. We detected three commonly deleted regions. One was located in a telomeric region of 10p and the others were relatively large regions of 10q. Our results suggested that three putative tumor suppressor genes on chromosome 10 are involved in the malignant progression of gliomas.

[A case of mycotic ICA petrous portion aneurysm treated with endovascular surgery]

A case is reported of mycotic aneurysm at the petrous portion of the internal carotid artery (ICA) treated with an endovascular procedure. A sixty-seven-year-old male who had suffered from chronic otitis media bilaterally for the last five years showed a sudden onset of massive left otorrhagia. Cerebral angiogram at the eighth day of otorrhagia disclosed a big aneurysm at the petrous portion of the left ICA. The aneurysm was round in shape but its wall was irregular. The angiogram also showed that a stenotic finding of the left ICA just at the proximal portion of the aneurysm and the neck of the aneurysm was not broad. Bone window computed tomography showed a destroyed petrous bone around the left ICA. The results of the Matas test and the Allcock test told us that left ICA occlusion should not be selected as a treatment. We decided that endovascular surgery could be applied as the treatment of this pathology. An endovascular procedure was performed for this pathology one month after the otorrhagia. The aneurysm was successfully embolized using platinum coils beside a part of the neck without occlusion of the parent artery. The patient's postoperative course was not eventful. We concluded that endovascular surgery might be the first choice for the treatment of an ICA petrous portion mycotic aneurysm.

Surgical treatment of a sacral nerve root cyst with intermittent claudication in an 85-year-old patient: case report

The following presents a case of an 85-year-old woman with intermittent claudication of a sacral nerve root cyst. The cyst wall was incised and oversewn while preserving the surrounding nerve fibers by microscopic procedures. All symptoms were eliminated following the operation. The syndrome of intermittent claudication may possibly arise while walking from the transient influx of cerebrospinal fluid into a cyst in a relatively narrow sacral canal. The present case may indicate that a sacral nerve root cyst is curable even in aged patients through thorough evaluation and management.

Intraoperative radiation therapy and chemotherapy for huge choroid plexus carcinoma in an infant--case report

A 2-month-old boy presented with a huge choroid plexus carcinoma in the left cerebral hemisphere. Almost total resection of the tumor was achieved, but a remnant abruptly enlarged 5 months later, requiring reoperation. After radical resection of the tumor, intraoperative radiation (10 Gy) was delivered. Postoperative chemotherapy was performed with methotrexate and vincristine, selected on the basis of in vitro chemosensitivity testing. No recurrence of the tumor was detected 18 months after the second operation. Radical surgery with these adjuvant therapies may be a good method to control this aggressive disease in infants.

Management of pilocytic astrocytoma

Pilocytic astrocytoma, when totally resected, has a favorable outcome compared to other astrocytomas. However, when residual tumor remains, the prognosis is less satisfactory. Our study addressed the issues of prognosis in cases of residual tumor and the effect of post-surgical radiation therapy on tumor recurrence. We analyzed 41 cases of pilocytic astrocytoma which were diagnosed by histologic examination. Twenty-six patients were 15 years old or younger, and 15 patients were 16 years old or older. An analysis of the relationship between age and tumor location revealed a cerebellar predominance in both age groups; however, there were more brain stem and basal ganglia tumors among adults. Overall prognosis was favorable, with a 2-year survival rate of 97.6%, 94.6% at 5 years, and 94.6% at 10 years. Children had a better prognosis than adults due to more favorable tumor location. Gross total resection resulted in the best prognosis, i.e., no recurrence during a 10-year follow-up period. Radiation treatment after surgery suppressed residual tumor. We concluded that the best treatment for pilocytic astrocytoma is: 1) total resection, if possible, followed by 2) irradiation of any residual tumor to suppress recurrence.

Transcingulate approach to lateral ventricle tumors. Technical case report

Surgical experience with treatment of two lateral ventricle tumors using the anterior transcingulate approach demonstrate that this route provides an excellent approach to tumors attached to the lateral wall of the anterior ventricle, without causing gross neurologic deficits. This approach deserves attention as an alternative to the transcallosal approach in selected patients.

[A case of multiple cerebral mycotic aneurysms treated with endovascular surgery]

A case of multiple mycotic cerebral aneurysms successfully treated with endovascular surgery is reported. A nine-year-old boy who has suffered from hypertrophic obstructive cardiomyopathy and active infectious endocarditis in the mitral valve developed sudden consciousness disturbance and convulsion. Computerized tomography revealed subarachnoid hemorrhage with subcortical hematoma in the left parietal lobe. Angiography demonstrated four aneurysms at the distal part of the middle cerebral artery on both sides. Since his physical status had been deteriorating, it was difficult to undergo a usual surgical operation. Therefore, endovascular surgery was performed. The catheter was super-selectively advanced to the parent artery of the left posterior parietal artery aneurysm which seemed to be the hemorrhagic source, and the embolization was performed using platinum coils and liquid embolization material. Angiography after embolization showed that the aneurysms had been successfully occupied by the materials while the aneurysm of the right anterior parietal artery had not responded antibiotic therapy. Therefore the second embolization was carried out to the parent artery of the aneurysm of the right anterior parietal artery one month later. The patient had no neurological deficit after embolization and no aneurysms have been detected by the follow-up angiogram after the second embolization. An endovascular approach might be an alternative useful treatment for cases in which the patient has, deteriorated so much that it is considered difficult to perform open craniotomy under general anesthesia.

[Primary malignant T-cell-rich B-cell lymphoma of the central nervous system: a case report]

An autopsy case of primary intracranial T-cell-rich B-cell lymphoma in a 69-year-old female is presented. The patient was admitted with a diagnosis of a brain tumor in July 1993 and a month long history of mental deterioration, motor weakness of the right arm and leg, and a tendency toward somnolence. Neurological examination revealed disturbance of consciousness, right hemiparesis, and papilloedema. However, her general physical examination was unremarkable. A CT scan and MR imaging revealed an irregular enhanced mass lesion at the paraventricular deep white matter in the bilateral parieto-occipital lobe. The patient was treated with surgical biopsy of the tumor followed by combined radiotherapy (a total of 50 Gy) and chemotherapy. Following repetitive episodes of remission and exacerbation, the patient expired about seven months after the onset of symptoms. Histopathological diagnosis of the tumor was malignant lymphoma (diffuse medium-sized cell type). In the immunohistochemical study, most of the lymphoma cells had T-cell markers, such as UCHL1. Some of the lymphoma cells were L26-positive. Neither glial fibrillary acidic protein nor neuron specific enolase were reactive with the lymphoma cells. At post-mortem examination, the specimens disclosed diffuse infiltration of medium-sized lymphoma cells. By contrast, most of the lymphoma cells were shown to be positive by the analysis of L26. None of the lymphoma cells exhibited the presence of UCHL1. These immunohistochemical evaluations conform to the criteria of T-cell-rich B-cell lymphoma.

Serial positron emission tomography imaging of changes in amino acid metabolism in low grade astrocytoma after radio- and chemotherapy-- Case report

A 37-year-old male with mixed glioma was treated with combined radio- and chemotherapy. The amino acid metabolism of the tumor site and normal brain was followed by positron emission tomography using [11C]methionine ([11C]Met). The accumulation of [11C]Met in the tumor decreased during therapy and slightly increased 7 months after completion of the therapy, but then decreased markedly. However, computed tomography revealed no notable changes. The contralateral gray matter also showed a gradual decrease of [11C]Met accumulation. These findings indicate that reduction of amino acid metabolism in the tumor continues after radiochemotherapy although neuroimaging reveals no further morphological changes. Such therapy also has long-term effects on normal brain tissue.

Anaplastic ependymomas: clinical features and tumour suppressor gene p53 analysis

We analyzed seven cases of anaplastic ependymoma, focusing on neuro-imaging, histopathology, and mutations of the tumour suppressor gene p53. Five of the seven tumours were supratentorial. All had both cystic and solid components, with fragment calcifications detectable on CT scan. The solid parts of the tumours were imaged as heterogenous hypo- or iso-intense areas with moderate enhancement on T1-weighted magnetic resonance images. Vascularity was not prominent on angiograms except for one case. Histologically, in addition to the WHO criteria, loss of typical cellular architecture, endothelial proliferation, and necrosis were commonly found. A mutation in Exon 5 of the tumour suppressor gene p53 was detected in one anaplastic ependymoma out of five tumours (two benign and three anaplastic ependymomas) examined by PCR-SSPC analysis of genomic DNA followed by direct sequencing. Anaplastic ependymoma typically presents as a calcified cystic tumour in the supratentorial parenchyma or transependyma. Mutations of p53 deserve further investigation to examine their possible role in the oncogenesis and malignant transformation of ependymoma.

How to treat incidental cerebral aneurysms: a review of 139 consecutive cases

BACKGROUND

Together with current advances in neuroimaging techniques, the chance of incidental discovery of unruptured cerebral aneurysms has increased and the selection of their appropriate management remains controversial. To provide current data about management results of patients with incidental cerebral aneurysms, we have made a retrospective review of 139 consecutive patients treated either by surgical or conservative means.

METHODS

The surgical indication for each patient was decided, carefully considering several factors respectively, including the surgical difficulty, aneurysm size, patient's age, and medical condition.

RESULTS

Forty-nine patients were managed conservatively. Eight (16%) of those conservatively managed patients had intracranial hemorrhage due to aneurysm rupture during the follow-up period (mean, 4.3 years). Seven of these eight patients died from a fatal subarachnoid hemorrhage (SAH). The follow-up data showed that the mean size of aneurysms with late hemorrhage was significantly larger than that of aneurysms without subsequent rupture. It was also confirmed that none of the 26 tiny aneurysms smaller than 4 mm in diameter had ruptured. Ninety patients harboring 119 incidental aneurysms less than 25 mm in diameter underwent surgery. There was no surgical mortality or morbidity in this series.

CONCLUSIONS

These excellent surgical results were presumably achieved due to the strict patient selection. In respect to the size of aneurysms, it seems to be justified to recommend surgery for patients with aneurysms larger than 5 mm in diameter.

Loss of heterozygosity at 11p15 in malignant glioma

Deletions of loci on chromosome 11p have been found frequently in several malignant tumors including gliomas, suggesting the presence of tumor suppressor genes. We analyzed 38 gliomas [26 malignant gliomas (grades III and IV) and 12 less malignant gliomas (grade I and II)] for loss of heterozygosity using microsatellite sequences on 11p as polymorphic markers. Loss of heterozygosity was found in 8 of 26 malignant gliomas (31%) but not in the less malignant gliomas. In the region with loss of heterozygosity, loci on 11p15.5-pter were commonly deleted. Our results suggest that a putative tumor suppressor gene involved in malignant progression of gliomas is located in an approximately 21-cM region on 11p15.5-pter.

Magnetic resonance imaging of titanium anterior cervical spine plating systems

Magnetic resonance imaging (MRI) of titanium anterior cervical plating systems and their effect on postoperative images were evaluated ex vivo and in vivo. The Synthes and Caspar plating systems were examined by 0.5- or 1.5-T MRI scanners. A phantom study of these implants showed that in spin-echo modes, the plates and screws were seen as areas of signal loss accompanying a marginal hyperintense band, which was more obvious in higher tesla magnetic fields. Distortion of the magnetic field was more prominent in T2-weighted images. In gradient echo mode, the plate and screws were seen as areas of signal loss larger than the size of the metal because of the magnetic susceptibility effect. Postoperative MRI produced images of the implants similar to those observed ex vivo. The Synthes plating system did not interfere with the evaluation of the spinal cord, and the Caspar screw (which penetrated the posterior cortex of the vertebral body) caused a small artifact to be present at the anterior aspect of the spinal cord. In addition to being able to provide fixation of the cervical spine, titanium anterior cervical plates allow superior MRI of the postoperative spine.

Ganglioglioma in the basal ganglia totally resected by a trans-distal Sylvian approach

A patient with a ganglioglioma in the basal ganglia is presented. An 18-year-old man presented with involuntary movement in his right hand and right homonymous hemianopsia. Computed tomography and magnetic resonance imaging revealed a cystic tumor with an enhancing nodule in the basal ganglia extending into the thalamus. The mass was totally resected by a trans-distal Sylvian approach and was histologically proven to be a ganglioglioma. This is a rare case of midline ganglioglioma in a patient who underwent gross total resection.

Multiple transcripts of the neurofibromatosis type 1 gene in human brain and in brain tumours

1. Neurofibromatosis type 1 is a common hereditary disorder characterized by the presence of multiple neurofibromas and café-au-lait spots, and is frequently associated with intellectual handicaps and brain tumours. The gene responsible for neurofibromatosis (the NF1 gene) codes for a protein of 2818 amino acids, termed neurofibromin, which has a domain related to mammalian ras GTPase-activating protein. 2. The NF1 gene gives rise to multiple transcripts generated by alternative splicing, that encode neurofibromin and its isoforms. These include type I mRNA coding for neurofibromin, type II mRNA coding for neurofibromin containing the insertion of 21 amino acids in the GTPase-activating protein-related related domain and mRNA coding for an N-terminal isoform lacking the GTPase-activating protein-related domain (N-isoform). 3. In the present study, the relative levels of mRNAs encoding type I, type II and N-isoform were determined by S1-nuclease mapping analysis in human brain tissue and in primary brain tumours obtained from patients with tumours unrelated to neurofibromatosis type 1. 4. These three mRNAs were expressed in all ten brain tumours and in every region of the brain examined, with the highest levels found in the cerebellum. Type I mRNA was the predominant form in the human brain except for the pons, whereas type II mRNA was predominantly expressed in eight out of ten primary brain tumours. 5. In contrast, N-isoform mRNA was similarly expressed in normal brain tissue and brain tumours. 6. These findings suggest that neurofibromin and its isoforms have important physiological roles in the human brain and that the altered expression of type I and type II mRNAs in brain tumours may be related to the tumorigenesis.

Contrast-enhanced MR imaging of dural sinus thrombosis: demonstration of the thrombosis and collateral venous channels

In order to study the role of Gd-DTPA-enhanced MR imaging in dural sinus thrombosis, precontrast and postcontrast imaging using Gd-DTPA in three patients with clinically unsuspected dural sinus thrombosis was reviewed. Comparisons were made with cranial CT scanning and cerebral angiography. Compared to CT, the postcontrast T1-weighted images more clearly revealed thrombus in the dural sinuses as a nonenhanced central area of intermediate intensity (but not flow void) surrounded by an enhanced rim. MR imaging also demonstrated secondary changes, including the presence of collateral venous channels and venous infarction.

[CT and MR imaging findings of sphenoidal masses]

CT and MR imaging findings of 57 sphenoidal masses were retrospectively reviewed to assess the possibility of differential diagnosis between them. Various kinds of masses such as pituitary adenoma, epipharyngeal cancer, mucocele, chordoma, chondroma, chondrosarcoma, distant metastasis, multiple myeloma, fibrous dysplasia, craniopharyngioma, hemangiopericytoma, giant cell tumor, primary sphenoidal cancer, malignant melanoma, leukemia, histiocytosis X, and giant cell tumor were included in this series. CT scanning was performed in all cases, while MR images were obtained in 48 cases using a spin-echo pulse sequence. The relative density of the masses, bony changes and calcification were evaluated on CT, and on MR images, signal intensity of the masses relative to the normal gray matter, contrast enhancement and extension/contour were evaluated. Although no single feature appeared to be specific to the masses, detection of calcification on CT, identification of the normal pituitary gland as deformed or displaced on T1-weighted images, signal intensity on T2-weighted images, and extension of the masses seemed to be useful and should be examined in terms of their ability to assist in differential diagnosis. Finally, accommodative classification of sphenoidal masses primarily based on presumed origin or mode of extension was attempted.

Multicentric glioma studied with positron emission tomography: a case report

Positron emission tomography (PET) studies of a multicentric glioma case were undertaken using 11C-methionine (Met) and 18F-fluorodeoxyuridine (FUdR). Met-PET revealed high accumulating lesion in both the left and right hemispheres, whereas in the FUdR-PET, the lesion on the right showed marked accumulation, but not that on the left. For both foci, the histologic diagnoses were anaplastic astrocytoma, but the lesion on the right showed higher density of undifferentiated tumor cells than that on the left. PET studies using Met and FUdR are effective in delineating the proliferative potential of glioma cells, which otherwise cannot be determined by histopathologic studies.

[Follow-up study of malignant astrocytomas showing complete response after initial treatment]

The prognosis for patients with malignant astrocytomas is still poor. The identification of groups of patients with good prognostic factors should be helpful in selecting the treatment strategies. In general, important prognostic factors are thought to be the extent of surgical resection required, age, performance status, duration of symptoms, location, and pathological tumor grade. The purpose of this present study is to evaluate the prognosis of patients with complete response (CR), that is, complete disappearance of the tumor mass in the contrast enhancement of computerized tomography (CT) scan after initial treatment. An additional purpose is to examine the effect of factors such as pathological tumor grade, location, age of patient, and the extent of surgical resection in achievement of CR. The subjects of the study were 81 patients with supratentorial malignant astrocytomas (45 males, 36 females) treated with surgical resection and radiochemotherapy in our division since 1980, and followed up for more than 5 years. There were 57 anaplastic astrocytomas (WHO grade III) and 24 glioblastomas (WHO grade IV). The extent of surgical resection and the response to the therapy were evaluated by CT scans. The Kaplan-Meier method was used in generating survival plots. Twenty-two cases (27%) showed CR at the end of the initial treatment, and the other 59 cases (73%) showed Non CR. Fifteen cases (26%) among 57 grade III patients and 7 cases (29%) among 24 grade IV patients showed CR. Tumor locations of CR cases were exclusively superficial with the exception of one case that involved deep structure. Average age of CR cases and Non CR cases were 34.4 and 49.7, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)