Biomedical subjects

L de Noronha

Publications and source records attributed to L de Noronha.

10 recordsLinked to original sources

PubMed2001

Pleomorphic xanthoastrocytoma: report of a case diagnosed by intraoperative cytopathological examination.

The authors present an unusual case of a 13-yr-old boy with a 3-mo history of seizures. A CT scan showed a contrast-enhancing mass located in the left temporal lobe. The patient underwent a stereotatic-guided craniotomy; intraoperative cytological diagnosis was performed by the smear technique, showing a pleomorphic xanthoastrocytoma. The tumor was totally resected. Definitive diagnosis was established by examination of paraffin-embedded material. Six months after the surgical intervention, the patient is doing well, with no radiological evidence of recurrence. The cytological differential diagnosis of giant cell lesions of the central nervous system is emphasized.

Adolescent↗

PubMed2001

Accuracy of the smear technique in the cytological diagnosis of 650 lesions of the central nervous system.

The authors analyzed the results of 650 lesions of the central nervous system submitted to intraoperative cytological diagnosis by the smear technique. Cytological and paraffin section diagnoses were compared. The following statistical values were obtained: accuracy of 97.3%, sensitivity of 97.9%, specificity of 95%, positive predictive value of 99.1%, and negative predictive value of 89.6%. The authors comment on their main pitfalls using this cytological diagnostic procedure.

Brain Neoplasms↗

PubMed2001

Histopathologic and morphometric evaluation of the skin abnormalities induced by erbium:YAG and carbon dioxide lasers in 10 patients.

In the 1960s, carbon dioxide (CO2) laser therapy started to be applied to eliminate wrinkles, actinic scars, and acne because of its capacity of induce intracellular water vaporization. However, recent studies have shown the efficacy of the erbium laser in removing delicate and moderate scars. Furthermore, the postoperative lesions induced by the erbium laser seem to resolve faster and with less erythematous pattern compared with lesions induced by the CO2 laser. The purpose of this study was to determine the immediate pathologic alterations caused by single applications of CO2 and erbium lasers and their association in human skin shreds. Ten white female patients aged 30 to 63 years underwent rhytidectomy, and their respective shreds, which were prepared for excision, were tattooed with the CO2 laser, the erbium laser, or a combination of both in random order and number of applications, before final removal. This project was approved by the local ethical committee. After surgical removal, these tattooed shreds were fixed in 10% buffered formalin and submitted to histopathologic analysis. Morphometric studies demonstrated the normal skin thickness and thickness of the laser-treated area, and their subtraction resulted in the ablation damage values. Residual thermal damage corresponded to the thickness of the affected skin from the most superficial layer of tissue in the laser-treated area down to the deepest dermal area with basophilic degeneration of collagen fibers. Our results showed that two CO2 applications resulted in greater ablation and residual thermal damage when compared with only one CO2 application. The same was true in comparisons of one and two applications of the erbium laser. Both results were statistically significant (p < 0.05). When one isolated erbium and one isolated CO2 application were compared, ablation damage was greater in the former group, although with no statistical significance. One CO2 plus one erbium application compared with one isolated CO2 application showed similar ablation damage but greater residual thermal damage in the latter group (p < 0.05). These observations might contribute to our understanding of the lesions caused in the human skin by erbium and CO2 lasers and eventually help determine the ideal laser combination for the appropriate surgical treatment.

Adult↗

PubMed1998

[Infantile desmoplastic ganglioglioma: a clinical, histopathological and epidemiological study of five cases].

Infantile desmoplastic gangliogliomas are rare tumors of the central nervous system, composed by a mixture of glial and neuronal cells and a fibrous stroma, which affect mainly young patients and arise from the surface of the cerebral hemispheres. We present five cases of infantile desmoplastic ganglioglioma: three were male and two were female. The ages ranged from three months and seven years (mean 2.62 years). The symptoms reflected the growth and topography of the tumors affecting the parietal (n = 3), parieto-occipital (n = 1), occipital (n = 1) lobes. Immunohistochemistry was performed in two cases with similar results to those reported in the literature.

Biopsy↗

PubMed1997

[Electron microscopy study in neurodegenerative diseases in childhood].

Neurodegenerative diseases are a group of disorders in which there is storage of abnormal material in cells throughout the body due to an enzyme defect. The authors present the experience in the diagnosis of the neurodegenerative diseases in infancy by electron microscopical study of skin, conjunctival and rectum material of 89 patients and 2 necropsy cases. The age of the patients ranged from 49 days to 13 years with speak age of incidence in first year of life (n = 28). Fifty patients were female and 39 were male. The most frequent sites of biopsy were the skin and conjunctival. Of the total 89 patients, 15 had a definitive diagnosis (16.8%) including 4 cases of gangliosidosis, 3 cases of mucopolysaccharidosis, a case of Gaucher's disease, a case of Niemann-Pick disease, 3 cases of neuronal ceroid lipofuscinosis and 3 cases of storage disease which could not be specified. The authors studied all these patients within clinic and ultrastructural aspects and concluded that electron microscopy is an important method in diagnosis of storage diseases but with a low sensitivity as a single "screening" test for patients with progressive encephalopathy.

Adolescent↗

PubMed1997

[Primary pediatric tumours of the central nervous system. Anatomopathological study of 623 cases].

Tumours of central nervous system (CNS) represent the second most frequent malignancy in children under 15 years of age but are the commonest cause of death. The authors present the epidemiologic and histopathologic analysis of 623 primary tumours of CNS occurring during the period 1990 to 1996 in paediatric patients. In this period 3318 biopsies of CNS were analyzed. In this total were included 623 paediatric tumours (18 7%). The age of patients ranged from 5 months to 15 years, 325 tumours occurred in males and 298 in females. The majority affected the posterior fossa. The majority of paediatric neoplasias were of glial origin (n = 277). The most frequent tumours were: astrocytoma (27.9%), medulloblastoma (9.95%), craniopharyngioma (5.93%), ependymoma (4.97%) and glioblastoma (3.37%).

Adolescent↗

PubMed1996

[Meningiomas. Epidemiological and anatomopathological study of 340 cases].

The authors have retrospectively reviewed all tumors of central nervous system (CNS) operated at the most important neurosurgery hospitals of Curitiba in a 5-year period (1990-1994) and found 304 (22.4%) cases of meningioma. Age mean of the patients was 48.5 years, with a range of 3 to 90 years. A marked female preponderance (68.7%) was noted. The most common tumor location was brain (n = 280) and the remaining cases occurred in spinal cord (n = 10), cerebellum (n = 9) and cranial nerves (n = 5). Histologically, there were 294 (96.7%) meningiomas of the classical type, six malignant or anaplastic, three atypical and one papillary. Two hundred and sixty seven classical meningiomas were from the meningotelial subtype, ten psamomatousos, five fibroblastic, five microcystic, five transicional and two angiomatous. The authors conclude that meningiomas are one of the most common group of primary neoplasias of CNS and the definition of malignancy in those tumors is beset by frequent discordance between histologic and biologic features.

Adolescent↗

PubMed1995

Sacrococcygeal chordoma in a 9-year-old boy.

A case of sacrococcygeal chordoma in a 9-year-old boy is presented. The symptoms at presentation were pain in both legs and sacrococcygeal region for the last two years that increased in the last four weeks irradiating mainly to the left leg. X-ray and CT scan examinations of the lumbar region revealed an expansive process in the coccygeal region with multiple calcifications and a partially eroded coccyx. There was no invasion of the retroperitoneum and regional lymph nodes. A biopsy was performed and showed cords and nests of cells with large cytoplasm, sometimes vacuolated, nuclei with moderate pleomorphism and clumped chromatin. Immunohistochemistry with avidin-biotin peroxidase technique showed positivity for CK, S-100 protein, CEA, vimentin and to EMA. Chordomas are a distinctly uncommon neoplasm in the first two decades of life, specially in the sacrococcygeal region. They have an aggressive behavior. Treatment of choice is complete resection.

Child↗

PubMed1994

[The importance of muscle biopsy in the diagnosis of neuromuscular diseases].

Most of the neuromuscular diseases have similar clinical presentation affecting mainly young patients. Clinical observations, serum enzymes, electromyographic studies and muscle biopsy are required for correct diagnosis. The authors show the results of morphological observations of a series of 124 muscle biopsies studied between 1988 and 1992 using conventional paraffin embedded material, frozen sections of muscle tissue stained by several histochemical techniques, electron microscopic observations and, in some cases, morphometric analysis of the smaller diameter of at least 100 random muscle fibres. Neurogenic atrophy was present in 27% of the cases (n = 33), dystrophic muscle was diagnosed in 26%, mitochondrial myopathy in 7% while inflammatory and metabolic myopathies were less frequent. In the group of muscle dystrophy most cases were of Duchenne type showing great variation in fibre size ranging from 10 to 110 microns (mean = 30 to 70 microns). There was also muscle necrosis and fatty changes. Neurogenic biopsies showed fibre atrophy with clustering of nuclei and group atrophy. Electron microscopic observations in cases of Werdnig-Hoffmann showed tiny fibres with less than 5 microns in great dimension and also with redundant basal laminae. Cases of mitochondrial myopathy showed the classical ragged red fibres and many different mitochondrial abnormalities under the electron microscope. Many cases (33%) showed only minor structural abnormalities or end-stage alterations with marked fatty infiltration and fibrosis so that a definitive diagnosis failed to be achieved. The correct selection and handling of muscle biopsies is important for adequate diagnosis in neuromuscular pathology.

Adolescent↗

PubMed1974

Thoracic kidney.

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Adult↗