Biomedical subjects
Publications and source records attributed to H Urich.
A case of gliofibroma occurring in an adult patient as a large circumscribed supratentorial tumor is reported. The bimorphic pattern was substantiated and further analyzed by immunohistochemistry. Some evidence in favor of collagen production by mesenchymal and/or inflammatory cells leading to a progressive fibrous replacement of the glial cells in this particular tumor type is presented.
Vascular permeability changes were examined in 34 tumours of the peripheral nervous system by immunohistochemical demonstration of serum proteins as endogenous tracers. The blood-tumour barrier was impaired in the reticular (Antoni type B) portions of neurinomas (Schwannomas) and in cutaneous neurofibromas but was similar to the normal blood-nerve barrier in fibrillary (Antoni type A) neurinomas, in most neurofibromas, in ganglioneuromas and in anaplastic tumours. These differences in permeability are discussed in relation to aspects of pathological tumour vascularization, the histogenesis of microcystic changes, and systemic therapeutic approaches.
Two published cases of medulloepithelioma, a rare malignant pediatric brain tumor composed of a mixture of primitive neuroepithelium and its differentiated neuronal and glial descendants, were examined by immunohistochemical staining for the presence of growth factors. From a panel of antibodies, those identifying basic fibroblast growth factor and insulin-like growth factor I, formerly known as somatomedin C, were strongly immunoreactive within the neuroepithelial cell population of the tumors. Immunoblots of purified recombinant basic fibroblast growth factor and insulin-like growth factor I showed antibody specificity without cross-reactivity. In controls, immunostaining of tissue sections was abolished by preabsorption of primary antibodies with the appropriate growth factor polypeptide antigen. Preabsorption with inappropriate growth factor did not reduce the intensity or alter the distribution of staining. The congruent histologic patterns of immunoreactivities suggest that more than one type of growth factor may be produced by the neuroepithelial component of medulloepithelioma. These growth factors may stimulate proliferation and differentiation of tumor cells by autocrine molecular mechanisms.
The authors describe the cerebral neuropathological findings of a 25 1/2-year-old male with 18q-syndrome. An abnormal gyral pattern, atrophy of the olfactory and optic nerves and small neocerebellar hemispheres with hemispheral lobular sclerosis were noted. Microscopically there were pial glioneuronal heterotopias; misplacement of neurons in the molecular layer of the cortex, as well as in deep white matter; not readily identifiable Betz cells; gliosis of olfactory and optic tracts and elsewhere; and loss of Purkinje cells. Further detailed studies of other cases are needed to determine whether these abnormalities are characteristic of the 18q-syndrome.
A case is presented of a 30-year-old, mentally retarded and epileptic patient, with a progressive hemifacial hypertrophy since birth. Repeated biopsies revealed the neurofibromatous nature of her facial lesion. Autopsy also revealed an ipsilateral hemimegalencephaly, as well as meningeal lipomas and osteomas. This combination of lesions represents an unusual variant within the spectrum of neurofibromatosis.
An exceptional type of cortical dysplasia is described in the brain of a 32-year-old woman who had received radiation therapy for a large pituitary adenoma 6 years before death. Markedly thickened gyri of the left inferior frontal, insular, and temporal cortex were found grossly. Microscopically, these gyri showed laminar disorganization and many unusually large and abnormally shaped ganglion cells. These neurons were heavily impregnated with silver preparations; were strongly reactive for neuron-specific enolase, synaptophysin, and neuronal cytoskeletal proteins (68- and 200-kd subunits of neurofilament protein, microtubule-associated protein 2, and tau); and ultrastructurally contained numerous perikaryal neurofilaments. Collectively, these findings suggest that the abnormally large, misshapen neurons contained excessive accumulations of cytoskeletal intermediate filaments. The present case and a similar one described in 1964 are the only two documented instances of neuronal gigantism apparently related to therapeutic irradiation of the brain.
The immunohistochemistry of the epidermal growth factor receptor (EGFR) was studied with monoclonal antibodies in 12 meningiomas of various histologic subtypes, nine benign and three malignant. Strong immunoreactivity of EGFR epitopes was found in the endothelia of the tumor vasculature in six cases. A much weaker reaction was detected within tumor cells in six cases, in one of which it was diffuse and five focal. No correlation was established between the presence of EGFR epitopes and the histologic type or biologic behavior of the meningiomas. The results suggest that the EGFR may participate in tumor angiogenesis, but its role in the growth of neoplastic meningioma cells remains elusive.
Monoclonal antibodies to non-phosphorylated and phosphorylated neurofilaments, as well as monoclonal and polyclonal antibodies to other cytoskeletal elements, were applied to the study of the cerebellar cortex of normal and pathological human material. The methods proved to be applicable to formalin fixed paraffin embedded tissue, provided the period of formalin fixation was short. The main difference between normal and pathological material was found in Purkinje cells and their dendrites. While normal Purkinje perikarya and dendrites expressed only non-phosphorylated neurofilaments, reactive dendrites stained more intensely with antibodies to phosphorylated neurofilaments. Similar observations were made on the abnormal dendritic ramifications of the partially deafferented, hypertrophic, inferior olive. The significance of the appearance of phosphorylated neurofilament epitopes in abnormal dendrites remains unknown and requires further investigation.
Serial biopsy specimens of a histologically proven cervical chordoma in a 57-year-old woman taken at intervals over a 7-year period, demonstrate a progression and complete transformation to a malignant fibrous histiocytoma 5 years following radiation therapy. Intermediate spindle-shaped cells demonstrating keratin positivity were discovered, lending credence to the theory of cellular transformation. Additionally, a fine reticulin network was noted around the chordoma cells. A review of the literature is undertaken chronicling the documented associations of chordoma and sarcoma, followed by a discussion of the various causes proposed to explain this phenomenon.
Five meningeal neoplasms grossly resembling meningiomas but histologically containing meningothelial cells together with abundant plasma cells and lymphocytes are reported. These masses are regarded as meningiomas with extensive plasma cell--lymphocytic infiltrates.
1) Destructive processes are responsible for most cases of cerebellar microgyria of the trabecular pattern. Erosion and subsequent fusion of the folia produce the disorganized pattern in which the various cellular elements retain their noraml relationship and are capable of normal maturation. Intrauterine infection is responsible for most cases; the evidence is conclusive in some cases, presumptive in others. 2) Faulty genetic coding, as illustrated by the trisomies, may lead to formation of heterotopias. The primitive cells aggregating around the dentate nucleus should be interpreted as matrix cells and not as cells of the external granular layer. Cortical heterotopias with attempted internal organisation also occur; their origin is obscure. The unusual, possibly unique, transposition of the internal granular and Purkinje cell layers observed in one case may be ascribed to faulty formation of the Bergmann glia by analogy with the weaver mouse. 3) It is impossible at present to disentangle the role of genetic and environmental factors in the pathogenesis of the hysraphic malformations. It is possible, however, that defective fusion of the intraventricular cerebellar primordium plays a part in the development of the Dandy-Walker malformation, of midine cerebellar clefts in some cases of occipital encephalocele, and of extra-axial ependymal cysts of the posterior fossa.
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A retrospective study of four tumours of the peripheral nervous system originally diagnosed as neuroblastomas or ganglioneuroblastomas has been made. The patients have all survived since the original diagnosis. Evidence of residual tumour was seen only in one patient, and was associated with evidence of increasing histological differentiation over a period of time. Maturation of primitive cell types is known to alter the prognosis of neuroblastic tumours. It is suggested first, that even minimal evidence of maturation indicates a better prognosis. Second, that evidence of maturation may be uneven, small areas occurring in otherwise totally undifferentiated tumours, or, immature areas remaining even in apparently benign fully mature tumours; if these areas show maturation the prognosis remains good and the tumour should not be confused with a composite ganglioneuroblastoma. Third, that maturing tumours may behave in a malignant fashion, invade and metastasise, but but with maturation of the primary tumour and its metastases the ultimate prognosis may be better than the initial behaviour suggests.
The validity of the concept of the angioblastic meningioma, now in dispute, was reexamined by reviewing 79 meningeal and angioblastic tumors of the central nervous system and by comparing the fine structural characteristics and in vitro evolution of 2 typical meningiomas and 1 intracranial hemangiopericytoma. While most tumors show the consistent features of either hemangiopericytoma or hemangioblastoma, there exist transitional forms between these tumors and typical meningioma. There is also a greater degree of morphological overlap at the electron microscopic level than has been recognized up till now. In view of these findings the concept of the angioblastic meningioma deserves to be retained as a generic term to include craniospinal hemangiopericytomas and transitional forms between hemangiopericytoma, hemangioblastoma and classic meningioma. It is postulated that all these tumors share a common origin from polyblastic mesenchymal cells originating in or derived from the meninges.
Biopsies of the external anal sphincter, puborectalis, and levator ani muscles have been examined in 24 women and one man with long-standing anorectal incontinence, 18 of whom also had rectal prolapse, and in two men with rectal prolapse alone. In 16 of the women anorectal incontinence was of unknown cause, but in eight there was a history of difficult labour. Similar biopsies were examined in six control subjects. In all the incontinent patients there was histological evidence of denervation, which was most prominent in the external anal sphincter muscle biopsies, and least prominent in the levator ani muscles. Myopathic features, which were thought to be secondary, were present in the more abnormal biopsies. There were severe histological abnormalities in small nerves supplying the external anal sphincter muscle in the three cases in which material was available for study. We suggest that idiopathic anorectal incontinence may be the result of denervation of the muscles of the anorectal sling, and of the anal sphincter mechanism. This could result from entrapment or stretch injury of the pudendal or perineal nerves occurring as a consequence of rectal descent induced during repeated defaecation straining, or from injuries to these nerves associated with childbirth.
A series of autopsy studies is presented of 13 cases of obliterative vascular disease of the vasa nervorum in a wide range of conditions, including polyarteritis nodosa, Wegener's granulomatosis, lymphomatoid granulomatosis, polymyositis and rheumatoid arthritis. In most cases, including 1 of rheumatoid neuropathy, the lesions were of the necrotising type. This supports the concept of polyarteritis nodosa as a pattern of reaction common to several diseases rather than that of a specific nosological entity. The remaining 4 cases of rheumatoid neuropathy, were associated with a bland endarteritis known as Bywater's arteritis. A comparison of these autopsy findings with clinical data and observations on sural nerve biopsies leads to the conclusion that all severe and most of the mild cases of rheumatoid neuropathy are due to occlusive vascular disease. Segmental demyelination independent of vascular lesions may be responsible for some of the mild cases and is frequently found in patients without clinical neurological manifestations.
Four cases interpreted as intraspinal blue naevi are reported. The patients were adults females with an age range between 22 and 60 yr. In three there was a single tumour arising from the cervical posterior nerve roots and in the fourth there were multiple tumours arising from the posterior nerve roots of the spinal cord and occurring within the cerebello--pontine angle. The histological appearances of the tumours were similar in every way to those of dermal blue naevi. One was of the more common spindle-celled type and three of the cellular variant. The tumours contained melanin-pigment, and spindle cells with dendritic bipolar processes of the type described in dermal blue naevi. One was of the more common spindle-celled type and three of the cellular variant. The tumours contained melanin pigment, and spindle cells with dendritic bipolar processes of the type described in dermal blue naevi. Definite evidence of malignant tranformation was found in two cases and in a third, the appearances were suggestive for early malignant change. Therefore, unlike their dermal equivalents, intraspinal blue naevi appear to have a greater propensity for malignant transformation. In each case a careful clinical examination failed to reveal any evidence of a primary malignant melanoma. In the one case who died and on whom necropsy was performed, the failure to identify a primary cutaneous, mucosal or ocular melanoma substantiated our contention that these tumours were primary.
Two cases of encephalomyelitis are described in which the major clinical manifestation was muscular rigidity and stimulus-sensitive muscular spasms. It is suggested, from pathological evidence, that this rigidity was of spinal origin, and that this disorder is a rare but recognizable entity. Comparison is made with previously reported cases of rigidity of spinal origin, including encephalitis lethargica, and with 'subacute myoclonic spinal neuronitis' and the 'stiff man syndrome.'