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Choroid plexus carcinoma. Case report.
Report concerns the uncommon cerebellar neoplasm of choroid plexus in 57-year-old woman, which was devoid of some anaplastic features causing doubts about degree of tumor differentiation. Immuno- and histochemical study presented positive CK, VIM, GFAP, S-100 immunostaining and positive PAS-dimedone reaction conforming histological diagnosis.
Pathology, genetics and cell biology of hemangioblastomas.
Hemangioblastomas are highly vascularized tumors of not well-defined histological origin which are frequently associated with cysts. They arise preferentially in cerebellum, medulla and spinal cord and are histologically indistinguishable from vascular lesions in the retina (so-called angiomatosis retinae). Hemangioblastomas are the most frequent manifestations of the von Hippel-Lindau (VHL) disease, an autosomal-dominant inherited cancer syndrome but also occur as sporadic non-hereditary tumors. The VHL tumor suppressor gene has recently been cloned and enormous progress has been made towards the understanding of molecular biology and biological function of the VHL gene. Germline mutations in VHL patients, as well as somatic mutations in different tumors, including hemangioblastomas, have been identified, its ability to act as a tumor suppressor in vivo has been confirmed, and interaction with transcription factors Elongin B and C leading to inhibition of transcriptional elongation has been demonstrated. The mechanism underlying neovascularization and cyst formation in hemangioblastomas and how this is linked to inactivation of the VHL tumor suppressor gene is not known. However, the finding of dramatic up-regulation of vascular endothelial growth factor (VEGF), a potent endothelial cell growth factor with vascular permeability-inducing activity, in stromal cells and the corresponding receptors, VEGFR-1 and VEGFR-2, in tumor endothelial cells suggests that angiogenesis and cyst formation in hemangioblastomas may be regulated by this signaling pathway via a paracrine mechanism.
The role of high-dose chemotherapy and stem cell rescue in the treatment of malignant brain tumors.
The outcome for the majority of children with malignant brain tumors remains poor, despite surgery, irradiation and conventional chemotherapy. In an attempt to improve this poor outcome, strategies utilizing high-dose (potentially myeloablative) chemotherapy with autologous stem cell rescue have been developed. These studies, initially conducted in patients with recurrent brain tumors, have now been extended to patients with newly diagnosed malignant gliomas and to young children with various malignant brain tumors at diagnosis in an attempt to avoid irradiation to the brain. The results of several of these studies are summarized, demonstrating durable disease-free survival for a proportion of patients with recurrent malignant gliomas and medulloblastoma/primitive neuroectodermal tumors, as well as encouraging preliminary data in the newly-diagnosed patients.
[Computerized tomography in pediatrics (author's transl)].
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[The Bouttier test. Significance of resistance to pressure for neurological diagnosis (author's transl)].
In 1922 Bouttier described the "pressure test". With reference to later works by Bouttier, not published at the time, the author demonstrates the role which the Bouttier test can play in the differential diagnosis of various neurological diseases (tumours of the cerebellum, the cerebellopontile angle or the pituitary; frontal tumours, cerebral atrophy, pseudobulbar palsy, Parkinson's disease). The physiological mechanisms which could play a part in these reactions are briefly considered. (Acta Neurol. Belg, 1977, 77, 193-201).
Primary intracerebral malignant fibrous histiocytoma: immunohistochemical findings and etiopathogenetic considerations.
We report a case of malignant fibrous histiocytoma (MFH) arising as a second malignancy in a 13-year-old girl with a previous primitive neuroectodermal tumor of the cerebellum (medulloblastoma). The earlier tumor had been resected and treated with chemotherapy. Because of the age of the patient, no radiation therapy was used. The second neoplasm (an MFH), which presented almost 12 years later, was located within the left frontal region and had discrete meningeal attachment. Histologically, it showed the characteristic storiform pattern and pleomorphism of an MFH and displayed characteristic immunohistochemical reactivity. Careful clinical and radiologic investigation failed to reveal any other neoplasm in the body. This case is unique in that the MFH occurred in a young child after an earlier primary primitive neuroectodermal tumor, although at a distant site, and, importantly, without prior radiation therapy. In this report, we briefly review the literature with an emphasis on immunohistochemistry and histogenesis, raising the possibility that the MFH was induced by chemotherapy.
[Cerebral SPECT with thallium-201 in the differential diagnosis of focal cerebral lesions in patients with AIDS].
BACKGROUND: The aim of this study was to analyze the usefulness of cerebral SPECT with thallium-201 in patients with the acquired human immunodeficiency syndrome (AIDS) and focal cerebral lesions. METHODS: Six patients with AIDS and focal cerebral lesions in whom a cerebral SPECT was performed with thallium-201 are described. Treatment was initiated with antiToxoplasma drugs in all patients. The clinical response, serology for positive toxoplasma and radiologic improvement were criteria for the diagnosis of encephalitis by Toxoplasma. In the remaining cases, cerebral biopsy and/or necropsy study were carried out. RESULTS: In the 2 patients in whom cerebral SPECT demonstrated enhancement of the lesion, the pathologic diagnosis was cerebral lymphoma. Of the 4 remaining cases in whom no enhancement was observed, three corresponded to cerebral toxoplasmosis and one to progressive multifocal leucoencephalopathy. CONCLUSIONS: Cerebral SPECT with thallium-201 is a simple, specific and useful technique for the differentiation of primary cerebral lymphoma from the remaining inflammatory cerebral lesions which may be present in AIDS patients.
Mutations in the human homologue of the Drosophila segment polarity gene patched (PTCH) in sporadic basal cell carcinomas of the skin and primitive neuroectodermal tumors of the central nervous system.
The human homologue of the Drosophila segment polarity gene patched (PTCH) has recently been identified as the tumor suppressor gene responsible for the nevoid basal cell carcinoma (BCC) syndrome (H. Hahn et al., Cell, 85: 841-851, 1996; R. L. Johnson et al., Science (Washington DC), 272: 1668-1671, 1996). In addition to multiple BCCs, patients with nevoid BCC syndrome have a predisposition for the development of primitive neuroectodermal tumors (PNETs) of the central nervous system. We have analyzed 9 sporadic BCCs and 37 PNETs for mutation and expression of the PTCH gene. PTCH mutations were found in 3 BCCs (33.3%) and in 5 PNETs (14%), including 1 of 5 cerebral PNETs, 2 of 15 medulloblastomas, and 2 of 17 desmoplastic medulloblastomas. The sequence changes in six of these tumors (four PNETs, two BCCs) were mutations predicted to result in truncated proteins. Missense mutations were detected in one PNET and one BCC each. In addition, novel sequence polymorphisms were found in exon 2, intron 5, intron 10, and intron 14 of PTCH. Reverse transcription-PCR analysis revealed increased PTCH expression levels compared to nonneoplastic brain tissue and normal skin in the majority of PNETs and BCCs investigated. Our data suggest that genetic alterations of PTCH are not only of significance in hereditary and sporadic BCCs but are also involved in the molecular pathogenesis of a subset of sporadic central nervous system PNETs.
[A case of intracranial rhabdomyo-sarcoma (author transl's)].
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Three-Hertz postural oscillation in patients with brain stem or cerebellar lesions.
Postural instability was quantitatively studied in patients with lesions in the 1) pontine tegmentum, 2) deep cerebellar nuclei, or 3) cerebellar hemisphere. As compared to controls, patients with each lesion demonstrated a characteristic 3 Hertz (Hz) body oscillation. Cross-correlation functions revealed a strong correlation between the body sway and activities in the lower leg muscles. Based on these findings, we conclude that the 3 Hz body oscillation may be the result of any disturbance in the loop of long-latency reflexes mediated by the cerebellum.
Cerebrospinal fluid cytology: an 11-year experience with 5951 specimens.
OBJECTIVE: Cerebrospinal fluid (CSF) diagnoses encompass a wide spectrum of conditions. The authors review one institution's CSF cytology results over an 11-year period. DESIGN AND SETTING: A retrospective study of 5951 CSF specimens generated between 1985 and 1995. Specimens from pediatric patients (<19 years of age) from the same time period were separately identified. RESULTS: A total of 5561 adult and 390 pediatric CSF specimens were interpreted. A diagnosis of "negative for malignant cells" was assigned in 5171 (93%) of the adult cases and in 351 (90%) of the pediatric cases. Specific infectious organisms were identified in 26 adult specimens and one pediatric specimen. Cryptococcus was the most common infectious agent observed (n = 23 adults), and Toxoplasma was the sole pediatric infectious agent. Two hundred seventy-six (5%) adult cases and 31 (8%) pediatric cases were positive for malignant cells. Diagnoses included metastatic tumors (adult, 140 [51%]; pediatric, 0); lymphoma/leukemia (adult, 112 [41%]; pediatric, 4 [13%]); malignant unclassified neoplasms (adult, 9 [3%]; pediatric, 0); and primary central nervous system neoplasms (adult, 12 [4%]; pediatric, 27 [87%]). Medulloblastoma was the most common pediatric neoplasm (n = 21). There were 105 (2%) adult cases and 8 (2%) pediatric cases with atypical cells present. Atypical lymphoid cells were the most common type in adult cases (53%). CONCLUSIONS: In our experience, infectious agents were rarely identified in pediatric CSF specimens. In adult specimens, the most commonly identified organisms was Cryptococcus. Primary central nervous system neoplasms accounted for a higher percentage of CSF specimens in the pediatric population than in the adult population. The most commonly identified malignancy in adults was metastatic neoplasms, and in children, medulloblastoma.
[Auditory brainstem responses in the diagnosis of retrocochlear hearing loss: selected case reports].
In this study, four cases of patients with retrocochlear hearing loss are presented (acoustic neuroma, cerebellopontine angle tumour, the fourth ventricle region tumour, inflammatory or vascular lesions in the fourth ventricle region). Standard audiometric tests, auditory brainstem response and radiological examinations such as CT scan and MRI were performed in all patients. The abnormal ABR observed in all cases suggested retrocochlear hearing loss. The presence of retrocochlear disorders was confirmed by CT or MRI. The analysis of presented cases showed that the abnormal ABR results should be a sufficient basis for referring the patient to MRI examination.
Familial occurrence of hemangioblastoma of central nervous system.
OBJECTIVE: To study the familial occurrence of hemangioblastoma of the central nervous system and to search for an effective way to diagnose and manage the disease. METHODS: From 1974 to 1993, six patients with hemangioblastoma with family history underwent surgical treatment at our hospital. Computerized tomography (CT) or magnetic resonance imaging (MRI) technique was used for the diagnoses before operation. RESULTS: Each patient had more than two relatives with hemangioblastoma. Multiple lesions were found in two of the six familial hemangioblastoma cases. All the patients recovered well after operation. So far, no victims have been discovered in the third generation. CONCLUSIONS: The high occurrence rate of familial hemangioblastoma cases suggests an involvement of hereditary factors. We need a long follow-up study on the descendants of familial hemangioblastoma patients. MRI is of diagnostic value in determining the location and nature of hemangioblastoma in both brain and spinal cord. A thorough examination is necessary for hemangioblastoma patients, and microsurgery is important in removing the tumor.
Development of a cavernous malformation of the brain.
We report the appearance of a cavernous malformation associated with a developmental venous anomaly in a young boy 3 years after radiation therapy for a posterior fossa medulloblastoma. The presence of a stenosis of the venous drainage of the anomaly led us to postulate that venous restrictive disease, induced by radiation therapy, resulted in increased venous pressure and caused the formation of the cavernous malformation.
Variations in the levels of the JAK/STAT and ShcA proteins in human brain tumors.
BACKGROUND: Recent demonstrations that the JAK/STAT and ShcA signalling proteins are abundant in the developing CNS at the stage of maximal cell proliferation prompted us to determine whether these proteins were expressed in various human brain tumors. MATERIALS AND METHODS: Using Western blot assay, we analyzed specimens from control peritumoral brain tissue, medulloblastomas, ependimomas, astrocytomas, anaplastic astrocytomas and glioblastomas. RESULTS: Our analyses revealed that Jak1 and Stat3 were consistently more elevated in low grade gliomas (LG) (tumors characterized by a more pronounced glial phenotype) as compared to high grade gliomas (HG) (less differentiated glial tumors). The other STAT proteins were equally expressed, while Stat1 was slightly higher in LG gliomas. Among the other tumors analyzed, medulloblastoma contained the highest level of Jak1 and Stat3, while ependymoma showed elevated levels of ShcA proteins. CONCLUSIONS: These differences may reflect differences in the biological characteristics of the various tumors and may provide insight for further mechanistic studies to investigate the importance of particular signal transduction pathways in CNS tumors.
[Brain tumors in childhood. Clinical aspects].
The analysis of 76 case histories of children suffering from brain tumor revealed a majority in preschool age. The diagnosis at admission to the hospital was correct in 2/3 of the cases. The main causes for admission among unclear cases were headache, a history of head trauma, and epilepsy. An evaluation is made of the diagnostic value of symptoms, neurological signs, and of auxiliary investigations.
O6-Methylguanine-DNA methyltransferase protein levels in pediatric brain tumors.
Chloroethylnitrosoureas (CENUs) are commonly used in the treatment of pediatric and adult central nervous system (CNS) tumors. The antitumor activity of CENUs has been hypothesized to be due to an alkylation occurring at the O6-position of guanine in DNA. The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) is responsible for the repair of these potentially cytotoxic lesions and may underlie tumor resistance to CENUs. The current study is the largest report of MGMT levels among newly diagnosed pediatric CNS tumors and the only study that has quantitated MGMT by both biochemical and Western immunoblot assays. Our results show a good correlation between the two methods (r = 0.66). Medulloblastoma/primitive neuroectodermal tumor and ependymoma had the highest level of MGMT, followed by high-grade glioma and low-grade glioma. These data may provide a guide to the use of CENUs in the treatment of pediatric CNS tumors.