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I Vajtai

Publications and source records attributed to I Vajtai.

35 records · Page 2Linked to original sources
PubMed1998

Rate and extent of early axonal degeneration of the human facial nerve.

Electrophysiologic and histologic studies on a severed human facial nerve have shown that 1) response to stimulation by electroneuronography was lost on the sixth day following injury, 2) wallerian degeneration progressed in a nonuniform "front," leaving some of the distal stump axons still viable and responsive to intraoperative stimulation 2 days following injury, and 3) the extent of proximal retrograde degeneration was far greater than to the next node of Ranvier. These findings are discussed in light of the current knowledge regarding peripheral nerve degeneration, and explanations are suggested.

Adult↗
PubMed1997

[Pleomorphic xanthoastrocytoma].

Pleomorphic xantho-astrocytoma (PXA) is a relatively rare brain tumor of adolescents and young adults characterized by its superficial location with frequent involvement of the meninges, and its slow growth despite features of histological atypia. The authors present a retrospective immunohistochemical analysis of 8 surgically treated cases in order to determine the expression of glial and neuronal markers, and to assess the proliferating cell fraction. The study population comprised 1 female and 7 male patients with a mean age of 26.7 years, most tumors being located in one of the temporal lobes. Epilepsy predominated as a presenting symptom. Five cases were assigned WHO graded II, while the diagnosis of anaplasia (WHO grade III) was established in three, based either on elevated mitotic counts or the presence of necrosis. Immunostaining with the proliferation marker MIB-1 was present in 2.05% of cells in the former groups, while 4.66% showed labeling in the latter. Postoperative follow-up averaged 6.7 years, with only one recurrence of an anaplastic tumor. All tumors expressed some amount of glial fibrillary acidic protein and were shown to elaborate a characteristic pericellular reticulin network. There was focal reactivity for alpha-1-antitrypsin, but neither the monocyte-macrophage associated antigen CD68 nor lysozym could be detected in neoplastic cells. In 7 cases, scattered individual tumor cells exhibited synaptophysin positivity. The authors review problems and prognostic issues of the histologic diagnosis of anaplasia occurring in some 20% of the cases. A possible dysontogenic origin of PXA and its nosologic relationship to the so-called desmoplastic neuroepithelial tumors of infancy are discussed. This is the first study of pleomorphic xanthoastrocytoma in the Hungarian literature.

Adolescent↗
PubMed1997

Pleomorphic xanthoastrocytoma with gangliogliomatous component.

We describe a composite glio-neuronal tumor comprising pleomorphic xanthoastrocytoma (PXA) and ganglioglioma identified in a left temporal biopsy. The 32-year-old male patient underwent surgery following a clinical history of persistent headaches of 6 years' duration. Immunohistochemical double labeling with antibodies to synaptophysin, beta-tubulin isotype III, GFAP and CD44H demonstrated neoplastic neurons and astrocytes in the ganglioglioma, while coexpression of glial and neuronal markers was found in a subset of PXA tumor cells variously showing giant cell or spindle cell morphology. There were gradual transitions between the two neoplastic populations. These findings raise the possibility of ganglioglioma having evolved by differentiation of bipotential PXA tumor cells along astrocytic and neuronal lineages. The PXA may, therefore, be closely related to desmoplastic neuroepithelial tumors of infancy, a group of neoplasms of presumed embryonal origin.

Adult↗
PubMed1996

[Neuropathology of Rasmussen syndrome].

Rasmussen's syndrome is a devastating epileptic disorder of young subjects characterized by pharmacoresistent partial sensorimotor convulsions, hemiparesis, and intellectual decline. The morphologic correlate of Rasmussen's syndrome is a chronic focal inflammation of the cerebral cortex leading to unilateral brain atrophy. The authors review light microscopic findings of three cases, where material was obtained by corticectomies of various extent. Patients included two young females, 6 and 8 years of age and a 21-year-old man with characteristic clinical features. Histology showed focal cortical infiltrates of lymphocytes, microglial nodules and neuronal loss with reactive gliosis. Immunohistochemically, lymphocytes were shown to be of T-cell lineage, while activated microglial cells were identified upon their expression of MHC II antigens. Prominent perivascular astrocytic reaction, as evidenced by the pattern of GFAP-staining, suggests recurrent injury to the blood-brain-barrier. The presence of Cytomegalovirus and Herpes simplex virus I and II could not be detected. The etiology of Rasmussen's syndrome is not known. The neuropathologic alterations, however, support the role of autoimmune-mediated neuronal excitotoxicity in its pathogenesis.

Adult↗
PubMed1996

[Primary cerebral T-cell lymphoma].

The authors describe a case of primary cerebral T-cell lymphoma observed in a 68-year-old man. The patient suffered from disseminated follicular carcinoma of the thyroid and the clinical picture has been dominated by neurological symptoms of presumed metastatic origin. Primary cerebral lymphoma was discovered at autopsy. Histologically, it proved to be a high-grade malignant pleomorphic non Hodgkin's lymphoma whose T-cell lineage was confirmed by immunohistochemistry. The patient did not manifest any congenital or acquired immune deficiency. There were neither cerebral metastases of the thyroid cancer nor any evidence for extracranial involvement by a lymphoma. Providing a brief literature review of cerebral T-cell lymphomas, the authors discuss some major traits of this exceptional form of lymphoid neoplasia of the central nervous system. Differential diagnostic and theoretical implications raised by cerebral lymphomas as second malignant tumors synchronously or metachronously associated with other malignant diseases are envisaged.

Adenocarcinoma, Follicular↗
PubMed1996

Melanotic astrocytoma.

A case of pigmented pilocytic astrocytoma (WHO grade I) incidentally found in a right temporopolar lobectomy specimen is reported. The patient, a 41-year-old woman, underwent surgery because of long-standing complex partial epilepsy of presumed post-traumatic origin. Using immunohistochemistry and electron microscopy, the tumor was shown to be composed of astrocytes without evidence of neurosecretory or melanocytic differentiation. The cytoplasmic pigment was identified as neuromelanin by its histochemical staining properties and ultrastructure. Although rare cases of ependymoma, subependymoma, choroid plexus papilloma and ganglioglioma with melanogenesis are on record, no melanotic astrocytoma has been described so far.

Adult↗
PubMed1996

Tubular adenoma of the choroid plexus: evidence for glandular differentiation of the neuroepithelium.

A case of tubular adenoma arising in the right ventricular choroid plexus of a 4-month-old boy is described. A basic pattern of neoplastic glandular epithelium and lack of papillary architecture distinguished this tumor from a papilloma. Coexpression of S -100 protein, transthyretin and cytokeratin identified the neoplastic cells as being of choroid plexus origin. Immunohistochemical detection of MIB-1 showed a proliferation rate (16%) similar to adenomas in more conventional locations, but not encountered in benign brain tumors. In situ detection of DNA-derived oligonucleosomal fragments by TUNEL analysis, on the other hand, detected apoptotic activity in 5-8% of tumor cells. The indolent course of the disease in the present case, thus, might suggest a compensatory elimination of proliferating cells by apoptosis. This possibly points to mechanisms of neoplastic transformation different from those involved in choroid plexus papillomas.

Adenoma↗
PubMed1996

The standard isoform of CD44 is preferentially expressed in atypical papillomas and carcinomas of the choroid plexus.

Isoforms of the CD44 adhesion molecule have been assigned a pivotal role in tumor invasion and metastasis. CD44 splice variants may be selectively expressed in various normal and neoplastic tissues. We investigated immunohistochemically the presence of the standard (H) and two variant (v3, v6) isoforms of the CD44 molecule in a series comprising 13 choroid plexus papillomas (WHO grade I) and 8 carcinomas (WHO grade III). In the papilloma group, 5 tumors showed variable cellular pleomorphism and foci of infiltrative growth, and were tentatively classified as atypical papillomas. Autopsy specimens of normal pediatric and adult choroid plexus were used as control. Western-blot analysis of CD44H was carried out on 4 carcinomas, 1 papilloma and on normal choroid plexus. The proliferation rate was assessed by MIB-1 immunoreactivity. The normal choroid plexuses and 9 papillomas were negative for the standard as well as the variant CD44 molecules investigated. Four atypical papillomas and 5 carcinomas expressed CD44H. CD44v3 and CD44v6 were only detected in one of the atypical papillomas also positive for CD44H. These data indicate that CD44H is preferentially expressed on atypical papillomas and carcinomas and may correlate with the infiltrative growth of these tumors.

Adolescent↗
PubMed1996

MIB-1 immunoreactivity reveals different labelling in low-grade and in malignant epithelial neoplasms of the choroid plexus.

MIB-1 immunohistochemistry was carried out on a retrospective biopsy series of epithelial choroid plexus neoplasms in order to assess the proliferation rate of tumour cells. The material included 14 cases of papilloma (WHO grade I) and five cases of carcinoma (WHO grade III). There was one recurrent tumour in the papilloma group, while three patients with carcinoma experienced recurrence. Choroid plexus obtained at autopsy from paediatric and adult patients with unrelated diseases served as control. The average MIB-1 labelling index of choroid plexus papillomas was 3.7%, while that of carcinomas was 14%, and that of normal choroid plexus was 0.02% to 0.06%. The age and sex of the patients as well as the tumour localization were not found to influence MIB-1 reactivity. The labelling index of recurrent lesions was not significantly different from that of the corresponding primary tumours. High MIB-1 labelling indices were associated with less favourable post-operative outcome in choroid plexus carcinomas and in one papilloma with atypical histology. However, most tumours with atypical histological features did not exhibit distinctive MIB-1 labelling indices. Analysis of growth fraction by MIB-1 immunohistochemistry may prove a useful ancillary method for assessing the malignant potential of choroid plexus neoplasms.

Adolescent↗
PubMed1995

[Dysembryoplastic neuroepithelial tumor].

The dysembryoplastic neuroepithelial tumor is a benign central nervous system neoplasm of children and young adults manifesting almost exclusively in complex partial seizures. The authors report the case of an 8-year-old boy presenting with characteristic clinical and radiologic features who subsequently underwent surgery. Light microscopic, immunohistochemical and ultrastructural traits of the tumor are described demonstrating pluripotential differentiation of tumor cells and architectural features suggesting a dysontogenic lesion. A brief literature review on the biology and histologic diagnosis of the dysembryoplastic neuroepithelial tumor is provided. Although this uncommon tumor accounts for only a minority of intracranial neoplasms, its pathogenetic role has to be considered in the differential diagnosis of temporal lobe epilepsies. This is the first report on this recently described, rare neoplastic condition in Hungary.

Brain Neoplasms↗
PubMed1995

[Symptomatic glial cysts of the pineal gland: report of two cases and review of the literature].

Referring to two individual cases, the authors review clinical, radiological and histological features of benign glial cysts of the pineal gland. Both patients were young females with aggravating headaches and with convulsions in one case. Symptoms were referable to a space-occupying cystic mass of the pineal gland. On histology, both lesions proved to be non neoplastic cysts without an epithelial lining. Their histogenesis and low growth potential were reinforced by immunohistochemical analysis of pineal antigens and proliferation markers. Glial cysts of the pineal gland are not infrequent, but symptomatic occurrences are exceptional. Most glial cysts are of dysontogenic or degenerative origin. Sometimes, however, the role of hormonal influences or paraneoplastic factors must be considered. Symptoms caused by glial cysts of the pineal gland are non-specific and radiologic imaging technics may contribute little to etiologic diagnosis. Pineal cysts are curable by surgical resection or stereotactic decompression. Whatever the diagnostic approach, emphasis must be laid on the histologic examination in order to avoid unnecessarily aggressive treatment.

Adolescent↗
PubMed1995

[Malignant melanoma evolving inside a cerebral epidermoid cyst].

A case of malignant melanoma arising in a cerebral epidermoid cyst is reported. The neoplasm presented as a rapidly enlarging mass in the left temporal lobe of a 52-year-old woman. The authors provide histological evidence for the provenance to tumour cells from the epithelial lining of the cyst. The melanocytic nature of the neoplasm was demonstrated by immunohistochemistry and electron microscopy. Post mortem examination ruled out the possibility of metastatic origin. The occurrence of intracranial epidermoid cysts and malignant melanoma, their eventual association with maldevelopmental processes or neoplasia are briefly reviewed. Although linked together histogenetically, epidermoid cysts and melanoma do not seem to be involved by common pathogenetic processes. To the best of our knowledge, no previous reference is available on malignant transformation of melanocytes in an epidermoid cyst.

Brain Diseases↗
PubMed1995

Melanotic papilloma of the choroid plexus: report of a case with implications for pathogenesis.

A case of pigmented choroid plexus papilloma removed from the 4th ventricle of a 43-year-old man is reported. The tumor showed histologic, immunophenotypic, and ultrastructural features of neoplastic choroid plexus epithelium. There was no evidence of melanosomal activity or neurosecretion. The pigment consisted of an intimate association of lipofuscin and neuromelanin, indicating autocatalytic peroxydation of the former as a putative way of melaninogenesis. The low proliferation rate of the tumor together with immunohistochemical evidence of inactivation of p53 protein suggest a delayed turnover of neoplastic cells as a possible source of lipofuscin accumulation.

Adult↗
PubMed1994

[Central neurocytoma: a rare tumor of the cerebral ventricles].

The case of a 33-year-old man is presented, who acutely developed disturbance of consciousness, symptoms of raised intracranial pressure and unilateral neurological signs. The underlying lesion was a hemorrhagic tumor located in the left lateral ventricle. On histological examination, the surgically resected mass proved to be a central neurocytoma, a benign neuroectodermal neoplasia. Difficulties in differential diagnosis by imaging technics and histopathology render this unusual lesion worth publishing. To the best of our knowledge, no similar report on this recently described rare entity has been published in Hungary.

Adult↗