1/35. Successful therapy in a child with a congenital peripheral medulloepithelioma and disruption of hindquarter development.PURPOSE: Medulloepithelioma is an embryonal multipotential neuroepithelial tumor with a striking potential for divergent differentiation. It is usually intraocular or intracerebral and associated with a good prognosis only if completely surgically excised. Data regarding therapy in children with incompletely resected tumors are limited. PATIENT AND methods: A girl was born with a large, peripheral, congenital medulloepithelioma associated with complete absence of the left hindquarter and anus. Plain film, ultrasonography, and magnetic resonance imaging demonstrated complete absence of the left kidney and hemipelvis. A subtotal resection of the mass and reconstruction of the tumor-related anatomical defects were performed. RESULTS: Pathologic examination showed neuroglia and pseudostratified neuroectoderm diagnostic of medulloepithelioma. She was treated with multiagent chemotherapy including vincristine, cisplatin, cyclophosphamide, carboplatin, and etoposide. She is now 50 months of age and developing normally without recurrent disease. CONCLUSIONS: A child with an incompletely resected congenital peripheral medulloepithelioma who has experienced long-term disease-free survival after treatment with chemotherapy is described. This report supports a role for adjuvant chemotherapy in the treatment of children with peripheral medulloepithelioma.- - - - - - - - - - ranking = 1keywords = mic (Clic here for more details about this article) |
2/35. Dysembryoplastic neuroepithelial tumor. A case report.Dysembryoplastic neuroepithelial tumor (DNT) is a rare, benign tumor encountered in the cortex. It is characterized by the presence of cells of different histogenesis. Due to its mixed nature (glial-neuronal), WHO histological classification of brain tumors included it into the group of neuronal and glial-neuronal mixed tumors. Case of tumor in a 19-year-old woman experiencing for three years seizure of temporal lobe epilepsy is presented. A cranial magnetic resonance imaging (MRI) showed "pseudocystic" tumor in temporal lobe. Histological and immunocytochemical examinations of the tumor fragment removed during surgery revealed large numbers of neuronalglial nodules occurring in the cerebral cortex. Columns of glial-neuronal structures crossing parallely to the cortex surface, surrounded by oligodendrocyte-like cells (OLC) were a characteristic feature of the tumor texture. In the tumor interstitium, "floating" maturated, dysplastic-free ganglionic cells were visible in numerous bright spaces. In addition, numerous lobuliform--structured areas consisted of oligodendrocyte-like cells. Oligodendrocyte-like cells were characterized by positive immunoreaction to the presence of S-100 protein and synaptophysin. Basing on clinical manifestation and histopathological findings dysembryoplastic neuroepithelial tumor was diagnosed.- - - - - - - - - - ranking = 1keywords = mic (Clic here for more details about this article) |
3/35. Dysembryoplastic neuroepithelial tumor (DNT): an ultrastructural study of six cases.We report six cases od DNT with a detailed ultrastructural characteristics. The patient age ranged from 7 to 16 years (mean 12), the location was temporal in three cases and frontal, temporooccipital and parietooccipital in each of one remaining cases. The predominant clinical feature in each case was history of episodes of intractable seizures. Histopathologically, the neoplasms were multinodular, each nodule was well-circumscribed and was composed of glioneuronal elements embedded in the variable amount of myxoid matrix. The oligodendroglial-like cells (OLC) predominated in the nodules with some accompanying mature neurons. The nodules were frequently surrounded by small calcifications which could be found also within the tumors. OLCs were immunoreactive for S-100 protein and neurons had the expression of synaptophysin and neurofilament proteins. Ultrastructurally, each tumor consisted of three major elements: neoplastic cells (OLC), elongated processes forming neuropil-like structure and expanded "mucoid" extracellular space: the latter gave an impression of cellular elements floating within it. Neoplastic cells had round, oval or elongated nuclei, no discernible nucleoli and a relatively narrow rim of the cytoplasm. Some nuclei were irregular and invaginated and pseudoinclusions were observed; a part of cytoplasm sequestered within pseudoinclusions often appeared degenerated with large blabs and electron-lucent vesicles, some of these contained in turn semicircular profiles of unknown significance. The second element consisted of innumerable cellular processes. Some of these were elongated and formed stacks connected by symmetrical symmetric or asymmetric adhesive plaque junctions. The others had shorter "neck" containing microtubules, these extended into bullous extensions. Dense-cored vesicles were occasionally observed, in both cytoplasm of neoplastic cells and within processes. In one cell, cross-sectioned annulate lamellae were found. In cytoplasm of a few cells, unusual inclusions reminiscent ribosome-lamellae complexes were observed. These were cylindrical resembling "laboratory tubes" with a cone-like endings. At higher power, walls of the "tubes" resolved into layered structures composed of several laminae; between laminae, ribosome-like structures were visible.- - - - - - - - - - ranking = 2keywords = mic (Clic here for more details about this article) |
4/35. Astroblastoma: ultrastructural observations on a case of high-grade type.An astroblastoma of high-grade type arising in the brain of a 3-year-old child is reported. The first description of the ultrastructural, immunohistochemical, and cytogenetic findings in this rare tumor variant are presented.- - - - - - - - - - ranking = 1keywords = mic (Clic here for more details about this article) |
5/35. MR spectroscopy in gliomatosis cerebri.BACKGROUND AND PURPOSE: The diagnosis of gliomatosis cerebri with MR imaging is known to be difficult. We report on the value of MR spectroscopy in the diagnosis, grading, and biopsy planing in eight patients with histopathologically proved gliomatosis cerebri. methods: patients underwent MR imaging and MR spectroscopy (single-voxel point-resolved spectroscopy [PRESS] at 1500/135, and chemical-shift imaging [CSI] PRESS at 1500/135) before open (n = 4) or stereotactic (n = 4) biopsy. In six patients who underwent CSI, biopsy samples were taken from regions of maximally elevated levels of choline/N-acetylaspartate (Cho/NAA). RESULTS: All patients showed elevated Cho/creatine (Cr) and Cho/NAA levels as well as varying degrees of decreased NAA/Cr ratios, which were most pronounced in the anaplastic lesions. In low-grade lesions, there was a maximum Cho/NAA ratio of 1.3, whereas in anaplastic tumors, the maximum Cho/NAA level was at least 2.5. Spectra in two patients with grade III lesions revealed a lactate peak; lactate and lipid signals were seen in two patients with grade IV lesions. biopsy specimens from regions with maximally elevated levels of Cho/NAA showed dense infiltration of tumor cells. CONCLUSION: MR spectroscopy might be used to classify gliomatosis cerebri as a stable or a progressive disease indicating its potential therapeutic relevance.- - - - - - - - - - ranking = 1keywords = mic (Clic here for more details about this article) |
6/35. Malignant transformation of a dysembryoplastic neuroepithelial tumor. Case report.A 29-year-old man presented in 1984 with a recent onset of partial seizures marked by speech arrest. electroencephalography identified a left frontotemporal dysrhythmia. Computerized tomography (CT) scanning revealed a superficial hypodense nonenhancing lesion in the midleft frontal convexity, with some remodeling of the overlying skull. The patient was transferred to the london health Sciences Centre for subtotal resection of what was diagnosed as a "fibrillary astrocytoma (microcystic)." He received no chemotherapy or radiation therapy and remained well for 11 years. The patient presented again in late 1995 with progressive seizure activity. Both CT and magnetic resonance imaging demonstrated a recurrent enhancing partly cystic lesion. A Grade IV astrocytoma was resected, and within the malignant tumor was a superficial area reminiscent of a dysembryoplastic neuroepithelial tumor (DNT). Data on the lesion that had been resected in 1984 were reviewed, and in retrospect the lesion was identified as a DNT of the complex form. It was bordered by cortical dysplasia and contained glial nodules, in addition to the specific glioneuronal element. The glial nodules were significant for moderate pleomorphism and rare mitotic figures. The Ki67 labeling index averaged 0.3% in the glial nodules and up to 4% focally. cells were rarely Ki67 positive within the glioneuronal component. This case is the first documented example of malignant transformation of a DNT. It serves as a warning of the potential for malignant transformation in this entity, which has been traditionally accepted as benign. This warning may be especially warranted when confronted with complex forms of DNT. The completeness of resection in the benign state is of paramount importance.- - - - - - - - - - ranking = 1keywords = mic (Clic here for more details about this article) |
7/35. Diagnostic value of immunocytochemistry in leptomeningeal tumor dissemination.Differentiating chronic aseptic meningitis from leptomeningeal carcinomatosis or gliomatosis can be difficult, particularly when the differentiation is based solely on routine cytologic examination. The diagnosis of cerebrospinal fluid tumor dissemination in at-risk patients requires cytologic examination of cerebrospinal fluid and radiography of the leptomeninges. Routine cytologic examination alone has proven less than desirable, in most instances providing confirmation in as little as 50% of cases in the first lumbar puncture. This percentage increases to 85% to 90% after multiple lumbar punctures. We retrospectively reviewed 2 cases of leptomeningeal dissemination (one gliomatosis, the other carcinomatosis) with initial false-negative test results. However, after further examination of the cerebrospinal fluid by selected battery of immunocytochemical stains, both cases were identified as positive for malignancy (ie, false negatives). Immunocytochemistry can be useful in distinguishing chronic aseptic meningitis from leptomeningeal carcinomatosis or gliomatosis in patients at risk or when abnormal cells are seen on routine cerebrospinal fluid cytologic examination.- - - - - - - - - - ranking = 1keywords = mic (Clic here for more details about this article) |
8/35. Diffuse cerebrospinal gliomatosis with extensive leptomeningeal spread.A case of diffuse cerebrospinal gliomatosis with extensive leptomeningeal spread is presented. The patient, an 18-year-old girl, was admitted due to progressive weakness and paresthesia of both legs, following rapid neuropsychiatric deterioration. An initial magnetic resonance imaging (MRI) study of the T-spine showed diffuse high signal intensities from T9 to T12 spinal cords on a T2 sagittal image and diffuse cord bulging at T1WI. This suggested an inflammatory lesion such as tuberculosis or fungal meningoencephalitis. A limited autopsy was performed. A microscopic examination revealed multifocal GFAP-positive astrocytic proliferations that were low grade astrocytoma in the cerebral leptomeninges, parietal, occipital and temporal lobes and anaplastic astrocytoma in the spinal cord and spinal leptomeninges. The high proliferative indices of the spinal lesion and aneuploidy correspond to a diagnosis of malignant astrocytoma and a rapid fatal clinical course.- - - - - - - - - - ranking = 1keywords = mic (Clic here for more details about this article) |
9/35. Astroblastoma: report of a case with microsatellite analysis.A 5-year-old girl who developed progressive headache, vomiting, and left hemiparesis was found to have a cystic tumor with an enhanced mural nodule in the right frontoparietal region on a computed tomography examination. The lesion was histologically and ultrastructurally verified as an astroblastoma, an uncommon neuroepithelial tumor of uncertain origin. Molecular analysis using 17 microsatellite markers on chromosomes 9, 10, 11, 17, 19, and 22 showed loss of heterozygosity at the D19S412 locus on the long arm of chromsome 19. This observation suggests that there is a tumor suppressor gene in this chromosomal region, which plays a role in the pathogenesis of astroblastoma.- - - - - - - - - - ranking = 5keywords = mic (Clic here for more details about this article) |
10/35. Dysplastic glioneuronal lesion arising in the cerebellum: a clinicopathological, immunohistochemical and ultrastructural study.We describe a case of dysplastic glioneuronal lesion in the right cerebellar hemisphere. A 13-year-old boy presented with headache since 1998. He had no neurological deficits. The computerized tomograph (CT) scan showed prominent calcification, and magnetic resonance imaging (MRI) revealed a non-enhancing mass of 15 x 15 x 5 cm in the right cerebellar hemisphere. The mass had low intensity in T1- and high intensity in T2-weighted images. Histologically, the lesion was composed of poorly defined small to intermediate sized cells arranged in fibrillar background. Although few neuronal cells having large nuclei with small nucleoli were present, no ganglion cells could be seen. Immunohistochemically, these poorly defined cells were non-reactive to various glial and neuronal markers. However, GFAP, synaptophysin, neurofilament and vimentin-reactive intercellular matrix and few nonneoplastic GFAP-positive glial cells and neurofilament-positive neuronal cells were seen. A very low MIB-1-labelling index of less than 0.1% was noted. Ultrastructurally, two different populations of the cells were seen. A few neuronal cells were larger and had an oval nucleus with small nucleolus and cytoplasm containing various cytoplasmic organelles, golgi apparatus, mitochondria, ribosomes, lipofuscin, rough endoplasmic reticulum, microtubules and neurofilaments. Many other cells had a scant cytoplasm and thus poorly defined. Cytoplasmic processes with axono-dendritic synapses and foci of bundles of intermediate filaments were present in the intercellular areas of the lesion. Based on these radiological, histological and ultrastructural findings of the lesion of low proliferative potential, we considered it dysplastic in nature.- - - - - - - - - - ranking = 9keywords = mic (Clic here for more details about this article) |
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