Malignant transformation in craniopharyngioma after radiation therapy: a case report and review of the literature.

OBJECTIVE: Craniopharyngioma is a benign epithelial tumor that is thought to arise from the remnant of the Rathke pouch. Malignant transformation in craniopharyngioma is extremely rare. Herein, we report a case of malignant transformation in craniopharyngioma after radiation therapy. MATERIALS AND METHODS: Histopathological and immunohistochemical analyses were carried out for specimens of the suprasellar tumor (from three resections, with the third surgery performed after radiation therapy). RESULTS: The resected tumors from the first and second surgeries comprised islands of loosely cohesive aggregates of epithelial cells, so-called stellate reticulum. At the periphery of the nests, palisaded columnar epithelium was observed. Wet keratins were scattered, and few mitotic figures were seen. The third surgical specimen was composed of irregular large nests of basaloid cells that had large, round to oval nuclei with prominent nucleoli, and mitotic figures were frequently seen (21/10 high power fields). In the center of the nests, eosinophilic ghost cells, resembling wet keratin, were observed. Accordingly, the diagnosis of malignant transformation in craniopharyngioma was made. Immunohistochemical studies revealed that the p53 protein was over-expressed in the malignant component, whereas its expression was much lower in the benign component. CONCLUSIONS: Similar to the ten previously reported cases of malignant transformation in craniopharyngioma, the present case occurred after radiation therapy. p53 protein overexpression was also observed in the earlier cases of malignant craniopharyngioma as well as in the present case (6/6 cases). We concluded that radiation therapy and p53 mutations could be involved in malignant transformation in craniopharyngioma.

Significance of MIB-1 staining indices in meningiomas: comparison of two counting methods.

The authors evaluated the predictability of MIB-1 immunohistochemistry for growth and recurrences of meningiomas using two different counting methods: 1) in the area of the highest MIB-1 labeling (HL method) and (2) in randomly selected fields (RS method). The MIB-1 staining indices (SIs) determined by the HL method were approximately twice as high as those by the RS method, and the correlation coefficient between them was high (R = 0.86) in 139 meningiomas when transformed logarithmically. The differences in SIs in histologic grades were significant with either method. Tumor doubling time (Td) was calculated in 22 meningiomas from serial radiologic examinations. The RS method yielded a slightly higher correlation coefficient between log Td and log SI than the HL method. When the authors examined the predictability of recurrence in 112 totally removed meningiomas, the RS method distinguished the recurrent group more definitively. Several benign meningiomas with low SIs by the RS method exhibited focal accumulation of MIB-1-positive cells. Although they were assigned high MIB-1 values by the HL method, these meningiomas did not recur, and therefore obscured the prognostic importance of the MIB-1 value with the HL method. Focal accumulation of MIB-1-positive cells in meningiomas is not likely to correlate with their biologic aggressiveness.

Atypical Rathke's cleft cyst associated with ossification.

We report a case of symptomatic Rathke's cleft cyst with ossification. CT scans showed curvilinear calcification on the wall of the cyst. MR images revealed a cystic sellar lesion with a nodular solid mass extending to the floor of the third ventricle. This case shows that calcification of the suprasellar cyst does not always suggest craniopharyngioma. Rathke's cysts should be histologically differentiated from craniopharyngiomas because their treatments are different.

Diffusion-weighted MR in experimental sustained seizures elicited with kainic acid.

PURPOSE: To investigate the early changes in diffusion-weighted MR images in the sustained limbic seizures. METHOD: Intraperitoneal injection of kainic acid was used to induce sustained limbic seizures in seven rats. The animals were investigated with serial 2.0-T MR imaging beginning immediately after kainic acid-induced seizures, and at 24 hours, 3 days, and 7 days after the kainic acid injection. Diffusion-weighted spin-echo and T2-weighted images and apparent diffusion coefficients were sequentially assessed and compared with histologic changes. The results were compared with eight control animals given buffered saline intraperitoneally. RESULTS: Diffusion-weighted MR images revealed an increase in signal intensity bilaterally in the amygdala and the piriform cortices immediately after the sustained seizures, whereas T2-weighted images did not show changes in signal intensity at this time. Both diffusion-weighted and T2-weighted images showed marked increase in signal intensities in these same areas 24 hours after kainic acid injection. The apparent diffusion coefficient values were significantly lower in the area of the amygdala and the piriform cortex immediately after and lower again 24 hours after the sustained seizures. The area of hyperintensity in diffusion-weighted images was concordant with the histologic distribution of neuronal pyknosis and neuropile vacuolation. CONCLUSION: Diffusion-weighted MR revealed focal abnormalities in the limbic system after 1 hour of sustained seizures induced with kainic acid, before changes on T2-weighted imaging. Diffusion-weighted MR is a potential method for studying the mechanisms of brain damage caused by sustained seizures.

Tentorial enhancement on MR images is a sign of cavernous sinus involvement in patients with sellar tumors.

BACKGROUND AND PURPOSE: This study was undertaken to analyze enhancement patterns of the dura around sellar tumors and to compare the results with tumor invasion or compression of the cavernous sinuses. Postoperative enhancement patterns on MR images were compared with preoperative findings. METHODS: Contrast-enhanced coronal and sagittal MR images were examined prospectively in 96 patients with sellar tumors (65 macroadenomas, 15 microadenomas, 14 Rathke cleft cysts, and two chordomas at the sella). All patients underwent surgical treatment, and pre- and postsurgical features on MR images were compared. RESULTS: Presurgical MR images showed dural enhancement in 36.5% of the patients: asymmetric tentorial enhancement in 24 patients, symmetric tentorial enhancement in seven, and sphenoidal ridge or clivus enhancement in four. Asymmetric tentorial enhancement disappeared after surgical decompression in seven patients. For evaluation of cavernous sinus invasion ipsilateral to the enhancement, sensitivity and specificity of the asymmetric tentorial enhancement sign were 81.3% and 86.3%, respectively. Sensitivity and specificity of the sign were 42.9% and 93.6% for cavernous sinus involvement, including compression and invasion. CONCLUSION: Asymmetric tentorial enhancement is a useful sign in the diagnosis of invasion or severe compression of the cavernous sinus by sellar tumor. The sign may represent venous congestion or collateral flow in the tentorium due to obstructed flow in the medial portion of the cavernous sinus.

Meningioma: proliferating potential and clinicoradiological features.

We examined the proliferative potentials of meningiomas in 120 patients using the MIB-1 antibody against the Ki-67 antigen and compared them with the clinicoradiological features. The Ki-67 staining index (SI) did not relate to the age and sex of the patients or the location of the tumors. Asymptomatic meningiomas showed significantly lower SIs (mean +/- standard deviation [SD], 0.87 +/- 0.56%) than symptomatic meningiomas (mean +/- SD, 1.63 +/- 2.17%). We found no relation between SIs and clinical symptoms and signs in the symptomatic meningiomas. A weak correlation was found between the size of tumors and Ki-67 SIs (r = 0.21; P = 0.024). There were significant differences in SIs between calcified (mean +/- SD, 0.77 +/- 0.41%) and noncalcified tumor (mean +/- SD, 1.75 +/- 2.25%). Diffusely calcified tumors (mean +/- SD, 0.57 +/- 0.34%) showed lower SIs than focally calcified tumors (mean +/- SD, 0.92 +/- 0.41%). Lobulated tumors showed higher SIs (mean +/- SD, 2.85 +/- 3.68%) than round tumors (mean +/- SD, 1.06 +/- 0.67%). Tumors with perifocal edema or unclear borders had higher SIs than did those without such features. Signal intensities on T1-weighted magnetic resonance images had no relation to SIs, whereas low-intensity tumors on T2-weighted images, most of which presented diffuse calcification on computed tomographic scans, showed lower SIs. This study indicates that several clinicoradiological features relate to the proliferative potential of meningiomas and that they may contribute to the management of patients.

Postoperative sella: evaluation with fast spin echo T2-weighted high-resolution imaging.

OBJECTIVE: The purpose of this study was to investigate the magnetic resonance features of the postoperative sella with fast spin echo (FSE) T2-weighted high-resolution imaging and to evaluate the benefits of the sequence using a follow-up magnetic resonance imaging protocol after transsphenoidal surgery. METHODS: Coronal spin echo (SE) T1-weighted and FSE T2-weighted images were prospectively obtained in 24 patients after surgery for pituitary adenomas. We observed the signals and the contour of normal structures, fluid collection, implanted materials, and mass lesions, including granulation tissue and adenoma. RESULTS: The pituitary gland was delineated in 51 of 59 FSE T2-weighted images, 90.2% of which presented clear boundaries. Whereas the gland was detected in 49 of 58 SE T1-weighted images, only 20.4% showed the boundaries. A mass lesion was identified in each of 12 patients with good resolution on FSE T2-weighted images. SE T1-weighted images detected mass lesions in 7 of 12 patients without distinctive boundaries. Contrast enhancement had little advantage in clarifying the boundaries between normal and abnormal structures. For the detection of mass lesions in the sella, the kappa values for interobserver agreement were 0.8 for FSE T2-weighted images and 0.25 for SE T1-weighted images. CONCLUSION: FSE T2-weighted imaging is a reliable method with which to assess the sella with sufficient resolution after transsphenoidal surgery. The combination of unenhanced SE T1-weighted and FSE T2-weighted images may reduce the use of contrast material after pituitary surgery.

Preoperative identification of meningiomas that are highly likely to recur.

OBJECT: Although generally they are well-circumscribed benign tumors, meningiomas recur even after complete removal. The aims of this study are to identify preoperatively groups of patients who have a high risk of meningioma recurrence by reviewing their clinicoradiological features and to plan appropriate treatments. METHODS: One hundred one patients who underwent macroscopically complete removal of meningiomas were observed postoperatively for at least 5 years or until tumor recurrence. Preoperative radiological findings and clinical characteristics were assessed. Fifteen meningiomas recurred during the follow-up period, which extended to a maximum duration of 18 years. On univariate analysis, tumor size and shape, relation to the major sinuses, calcification, bone changes, and characteristics of the tumor-brain interface were significant predictive factors for recurrence. Patient age and gender were not deemed significant. Multivariate analysis revealed that only the shape of the tumor was significant; both "mushrooming" and lobulated meningiomas were more likely to recur than round ones. Recurrences most frequently occurred at the edge of the dural resection after a Simpson Grade I removal, whereas local recurrences were predominant after a Simpson Grade II or III removal. CONCLUSIONS: Meningiomas with mushrooming or lobulated shapes should be treated more aggressively with a wider dural excision. This is not usually necessary for round tumors, although it may be beneficial in younger patients.

Noninvasive evaluation of the malignant potential of intracranial meningiomas performed using proton magnetic resonance spectroscopy.

OBJECT: Controversy exists about correlations between histological tumor grade and magnetic resonance (MR) spectroscopy data. The authors studied single-voxel proton MR spectroscopy as a noninvasive way to evaluate grade of malignancy in intracranial meningiomas. METHODS: The authors compared the results of MR spectroscopy with those derived by the MIB-1 staining index (SI) in 29 meningiomas. Proton MR spectroscopy was performed using stimulated echo acquisition and volume-localized solvent-attenuated proton nuclear MR sequences before surgery or other therapy. Twenty-four tumors were histologically benign (13 meningothelial, three fibrous, four transitional, three angiomatous, and one chordoid); four were atypical (Grade II), and one was papillary (Grade III). The mean MIB-1 SI in the benign group was significantly lower than those in the other groups (p = 0.0041). The mean choline-containing compound (Cho)/ creatine and phosphocreatine (Cr) ratios in the benign and nonbenign groups were 2.56+/-1.26 and 7.85+/-3.23, respectively (p = 0.0002). A significant linear correlation was observed between the Cho/Cr ratio and the MIB-1 SI (r0.05 = 0.74, p<0.001). Necrosis was present histologically in four of the five meningiomas classified either as atypical or papillary. Magnetic resonance spectroscopy revealed a methylene signal in these meningiomas that was not detected in benign meningiomas. Of the five meningiomas in which only a lactate signal was observed, two were benign and the MIB-1 SI in these two benign meningiomas was higher than the mean value for the benign group. Alanine, detected in 12 of 30 meningiomas, did not correlate with either tumor grade or Cho/Cr ratio. CONCLUSIONS: Proton MR spectroscopy is a useful diagnostic method for determining the proliferative or malignant potential of meningiomas according to the Cho/Cr ratio. A lactate and/or methylene signal suggests a high-grade tumor.

Anomalous p27kip1 expression in a subset of malignant gliomas.

p27Kip (p27) expression was immunohistochemically investigated in 28 astrocytic tumors, and compared with the cell proliferation index (MIB-1 staining index). Normal rat brains and surgical specimens from human nonneoplastic brain lesions were used as controls. In the rat brains, the astrocytes were exclusively p27-positive. The reactive astrocytes in various disease processes sometimes lacked p27 expression. The distribution of p27-positive cells was uniform in low-grade astrocytomas and heterogeneous in high-grade tumors. Double staining of p27 and MIB-1 showed a reciprocal pattern in most cases. The frequency of p27 expression was inversely correlated with MIB-1 staining index and tumor grade. However, several malignant gliomas showed high p27 expression in spite of high MIB-1 staining indices. In such cases, MIB-1-positive cells were occasionally p27-positive. In this paper we discuss the etiology of the anomalous p27 expression in a subset of malignant gliomas.

Alteration of bcl-2 and bax expression in embolized meningiomas.

We examined the expression of the p53 and bcl-2 family in embolized meningiomas and investigated the interaction between them. p53 and its downstream effector p21 accumulated mainly in perinecrotic areas, where apoptosis was also observed. bcl-2 was often expressed in the areas distant from necrosis, whereas Bax was immunostained more intensely in the perinecrotic areas. Double staining for both p53 and Bcl-2 showed a reciprocal pattern. This appeared to be due to the down-regulation of Bcl-2 by p53. However, regulation of Bax by p53 was not distinct. The expression of p21 was not apparent 13 days after embolization, and apoptosis was observed until 6 days after embolization. The effect of embolization was most likely temporary, although growth arrest has been reported to persist for a long time in a limited number of embolized cases.

Facial nerve palsy following therapeutic embolization.

Ischemic neuropathy is a previously described but rarely encountered complication of therapeutic embolization. Two cases of peripheral facial nerve palsy following embolization of branches of the external carotid artery are reported, and the possible mechanism is discussed.

Anaplastic ganglioglioma with dissemination to the spinal cord: a case report.

BACKGROUND: Gangliogliomas are rare tumors that generally arise in the temporal lobe. Although most are benign, malignant gangliogliomas have been reported. The clinical course of anaplastic gangliogliomas has not been well understood. CASE REPORT: An anaplastic ganglioglioma of the right parieto-occipital lobe is reported in a 7-year-old girl who presented with left homonymous hemianopsia and papilledema. Neurologic examination revealed a choked disc and a left homonymous hemianopsia. A computed tomographic scan and magnetic resonance imaging showed a large enhancing mass with calcification. Radiation therapy was administered after subtotal resection of the tumor. Histologic and immunohistochemical studies showed a typical appearance of anaplastic ganglioglioma. Spinal dissemination developed 3 months after the operation. In spite of spinal axis radiation and chemotherapy, she expired 15 months after the diagnosis. CONCLUSION: Although the clinical course of anaplastic gangliogliomas is not always aggressive, our case indicates the importance of strict follow-up assessments of the whole craniospinal axis.

Amenorrhea-galactorrhea syndrome with craniopharyngioma.

Two cases of craniopharyngioma presenting with amenorrhea-galactorrhea syndrome due to hyperprolactinemia are reported. After operation and irradiation, the tumor reduced markedly in size. Coincidental decrease in plasma prolactin level and restoration of menstruation seem to support the view that the hypothalamic prolactin inhibiting factor (PIF) had played an important role in hyperprolactinemia in these two patients.

Cerebral hemodynamics in patients with normal pressure hydrocephalus: correlation between cerebral circulation time and dementia.

Regional cerebral blood flow and regional cerebral circulation time were measured in 13 demented patients with chronic hydrocephalus, mostly normal pressure hydrocephalus. The average hemispheric, frontal, and temporal cerebral blood flows were significantly reduced. The average regional cerebral circulation time values were significantly prolonged in the frontal, temporal, and thalamic regions, most markedly in the frontal white matter, where periventricular lucency was observed on computed tomography. Clinical improvement was obtained in all patients after operation. While postoperative regional cerebral blood flow values did not change compared with preoperative ones, postoperative regional cerebral circulation time values were significantly reduced in all the regions measured, and most markedly in the frontal white matter. The present results suggest that microcirculation in the frontal lobe is closely correlated with dementia in association with pressure exerted on the nerve fibers in the frontal white matter in patients with normal pressure hydrocephalus.

Primary carcinoma of the choroid plexus in the lateral ventricle.

Primary carcinomas of the choroid plexus are rare and occur more frequently in children than in adults. They have been posing a problem in their differential diagnosis from benign papilloma of the choroid plexus, ependymoma, and metastatic tumors of extracranial origin. A case of a 31-year-old woman with primary carcinoma of the choroid plexus in the trigone is reported. Electron microscopic and immunohistochemical studies are helpful, but not decisive yet, to reach the diagnosis. The literature is reviewed.

Suprasellar yolk-sac tumor in two sisters.

The familial occurrence of intracranial tumors is rare except in patients with phacomatoses. The occurrence of suprasellar yolk-sac tumors in two sisters without phacomatoses is reported. The pertinent literature is reviewed, and the possible role of heredity in the pathogenesis of these tumors is discussed briefly.

Multiple sinus pericranii with systemic angiomas: case report.

The authors report the case of an adult male who had multiple sinus pericranii, as well as angiomas in the retina and the skin of the knee. Although sinus pericranii is well documented, a simultaneous involvement in as many as four separate regions has not been reported. Clinical, radiographic, and histopathological features are detailed. Implications for the role of surgery and management is discussed.

Incidental meningiomas in autopsy study.

Two hundred thirty-one cases of incidental meningiomas found at autopsy at the Montefiore Medical Center during the period from 1950 to 1982 were reviewed. The prevalence of incidental meningiomas increased with age, and was highest in people 80 years of age or older. The male to female ratio was 1 to 3. The relative size of the tumors also increased with age. Multiple meningiomas were found in 8.2% of the cases; none of them had stigmata of neurofibromatosis.

Dynamic computed tomography and functional imaging in cerebral vascular anomalies.

Dynamic computed tomography was performed on patients with cerebral vascular anomalies, the density-versus-time curves were derived, and the gray-scale functional images demonstrating the pixel-by-pixel distribution of several flow parameters were processed. This noninvasive method was found to be useful not only in delineating the vascular anomalies with their afferent and efferent vessels, but also in detecting the abnormal flow patterns within and outside the vascular anomalies. Limitations and distinct advantages of this technique are briefly discussed.