Hallazgos histopatológicos que participan en la conducta biológica de los tumores de plexos coroides

Tesis (Maestría en Ciencias en Investigación Clínica), Instituto Politécnico Nacional, SEPI, ESM, 2008, 1 archivo PDF, (92 páginas). tesis.ipn.m

Intraventricular Neurilemmoma (Schwannoma): Shall GFAP Immunostaining Be Regarded as a Histogenetical Tag or as a Mere Histomimetical Trait?

Neurilemmomas are benign neoplasms presumedly derived from Schwann cells which rarely originate within the central nervous system. Moreover, their intraventricular location has been seldom noticed with less than 30 cases reported worldwide. Here, we add another case study to the record as well as the fifth one in Latin American population. A 16-year-old boy without significant past clinical data debuted with headache and progressive left eye blindness during six months. Neuroimaging scans showed a bulky, multiloculated, intraventricular tumour emerging from the posterior horn of the left lateral ventricle. Microscopically, the lesion put on view the classical schwannian histology: spindle cells arranged in both compact and loosely textured areas. Verocay bodies were not present but vessel hyalinisation, pericellular reticulin, and senescent atypia were observed. The immunoperoxidase reactions were also consistent with neurilemmal differentiation; however, glial fibrillary acidic protein expression was widespread and unexpectedly seen. Traditionally conceived as “nerve sheath tumours” the dual immunophenotype herein demonstrated points to a different histogenetical pathway other than sheer Schwann cell derivation. As previously advised by some authors, neoplastic transformation from a multipotent stem cell may explain the occasional finding of these tumours in unconventional intracranial compartments

Expression of Collagen VI, Anticollagenase, Laminin, MM9, Claudins 1 and 5, N and E Cadherins in Choroid Plexus Tumors

Background: CPTs are rare intraventricular papillary neoplasms derived from the choroid plexus epithelium. Anti-collagenase and extracellular matrix which have not been expressed in brain tumors. Objective: The purpose of this study was to investigate the expression levels of collagen type VI, anti-collagenase, laminin, MM9, claudins 1 and 5, N and E cadherins, and collagen VII, tejido, and collagen degradation enzyme complexes in choroid plexus tumors.Materials and methods: We studied the expression of adhesion molecules, extracellular matrix, and anticollagenase with an immunohistochemistry approach and electron microscopy analysis in 42 choroid plexus tumors. Results: 28(67%) were choroid plexus papillomas, 8 (19%) were atypical choroid plexus papillomas and 6 (14%) were choroid plexus carcinomas. The Ki67-li and MVD increased from CPC to ACPP, being the highest in malignant tumors as well as a strong immunoexpression of anti-collagenase and were inverse correlation with claudin 5, E, and N cadherin and collagen IV immunoexpressions which added further significant information to the prognosis and varied according to the histologic classification. By ultrastructure, the loss of basal membrane and cilia, disorganization, and proliferation of ECM were observed in CPC. Cerebral homeostasis largely results from the ability of both the Blood–Brain Barrier (BBB) at the brain microvascular endothelium and the Blood–Cerebrospinal Fluid Barrier (BCSFB) at the epithelium of the Choroid Plexuses (CPs), to control the composition of the CSF and cerebral extracellular fluid. Under expression of the tight junction proteins occludin, claudin-1 and claudin-5 are key molecular abnormalities responsible for the increased permeability of tumor endothelial tight junctions. Conclusion: The loss of basement membrane and ECM overexpression could be considered as a poor prognosis predictor in CPT. Anti-collagenase and MMP9 overexpression could be related to basal membrane and BBB plasticity in CPTs

Alteraciones cerebrales en enfermedad hipertensiva asociada a embarazo

La mortalidad por eclampsia varía entre el rango de 0 al 20% según las diferentes series a nivel mundial. La muerte de las pacientes con eclampsia puede presentarse como resultado de la asociación de factores clinicopatológicos y terapéuticos. Una frecuencia alta de muerte por eclampsia se atribuye a complicaciones cerebrales y sobre todo a la hemorragia cerebral, factores que se asocian a daño renal y hepático, así como a la coagulación intravascular diseminada, situación que se presenta en el 15% de las muertes por hipertensión arterial asociada a embarazo. Objetivo: se estudiaron las lesiones cerebrales en 30 casos de autopsia, de pacientes con eclampsia, es un estudio retrospectivo, observacional, descriptivo. Material y métodos: en el servicio de patología de Hospital General Dr. Manuel Gea González, de la Secretaría de Salud. Se revisaron los casos de autopsia de eclampsia / preclampsia, el estudio se basa en el análisis de resultados de laboratorio clínico y del estudio morfológico de las lesiones cerebrales en 30 casos. Resultados: 11 fueron preclampsia y 19 casos (63.7%) eclampsia. 15 (50%) presentaron síndrome de HELLP, de los cuales 3 casos (27.3 %) con preclampsia y 12 casos (63.2%) con eclampsia. Todos los casos presentaron cifras arteriales por arriba de 130 mmHg la sistólica y por arriba de 90mm/Hg la diastólica. El 60% de los casos, presentó en el tercer trimestre de la gestación y el 40% en el segundo trimestre. La hemorragia cerebral temporal se presentó en el 23%, hemorragia cerebelosa y occipital en el 26%, en puente en el 33%, edema cerebral en el 100%, encefalopatía hipóxica en el 92%, hemorragias parenquimatosias y petequias en el 33%, infartos cerebrales en el 16%

Lipomatous/Extensively Vacuolated Ependymoma with Signet-Ring Cell-Like Appearance: Analysis of a Case with Extensive Literature Review

“Lipomatous” and “extensively vacuolated” are descriptive captions that have been used to portray a curious subset of ependymomas distinctively bearing cells with a large vacuole pushing the nucleus to the periphery and, thus, simulating a signet-ring cell appearance. Here, we would like to report the first ependymoma of this kind in a Latin American institution. A 16-year-old boy experienced cephalea during three months. Magnetic resonance imaging scans showed a left paraventricular tumour which corresponded to anaplastic ependymoma. Intriguingly, it was also composed of cells with single or multiple hollow cytoplasmic vacuoles sometimes giving a signet-ring cell-like configuration. Immunolabeling of these showed membrane positivity for GFAP, PS100, and CD99, while Ki-67 expression was null. Ultrastructural examination of retrieved paraffin-embedded tissue showed the presence of scarce microlumina filled with microvilli but failed to demonstrate any content in such optically empty vacuoles as only scant granulofibrillary debris was observed. A schism prevails at present regarding these unusual morphological variants, being either “lipomatous” or “vacuolated” based mainly on the EMA immunoprofile. This, however, is a misappropriate approaching. Could it be that perhaps we are dealing with the same histopathological entity or it may simply happen that fixation and artefacts cannot allow for their proper identification