Expresión inmunohistoquímica de la proteína p53 en relación con el grado histológico y riesgo de recidivas en meningiomas intracraneanos

Los meningiomas son neoplasias primarias frecuentes del sistema nervioso central, usualmente benignas y susceptibles de curación mediante cirugía. El grado histológico de la Organización Mundial de la Salud y la extensión de la resección quirúrgica inicial son factores pronósticos determinantes en estos tumores. Sin embargo, una tasa de recidiva cercana al 20 por ciento en meningiomas benignos totalmente resecados plantea la necesidad de considerar nuevos factores pronósticos. Un total de 93 casos fueron seleccionados para el estudio inmunohistoquímico de la proteína p53 en relación con el grado histológico y riesgo de recidivas en los meningiomas. El índice de marcaje inmunohistoquímico de la proteína p53 se incrementó con la progresión del grado histológico (promedios de 37,15 por ciento para el grado I, 44,49 por ciento para el II y 57,81 por ciento para el III) y fue significativamente superior en meningiomas recidivantes (46,19 por ciento vs 32,29 por ciento de los no recidivantes). El punto de corte de 40 por ciento resultó estadísticamente útil para separar a los meningiomas benignos (grado I) de los no benignos (grados II-III) y a los tumores recidivantes de los no recidivantes. De esta manera, un índice de marcaje de la proteína p53 igual o mayor de 40 por ciento puede indicar la posibilidad de un grado más alto en casos histológicamente ambiguos o un riesgo mayor para desarrollar recidivas en meningiomas de un grado histológico en particular (especialmente en tumores benignos)

Meningiomas are frequent primary neoplasms of the central nervous system, usually benign and susceptible to healing through surgery. The histological grade of the World Health Organization and the extension of the initial surgical resection, are determining prognostic factors in these tumors. Nevertheless, a recurrence rate close to 20 percent in benign meningiomas completely resected arises the need of considering new prognostic factors. A total of 93 cases were selected for the immunohistochemical study of p53 protein in relation to the histological grade and the risk of recurrences in meningiomas. The immunohistochemical labeling index of p53 protein increased with the progression of the histological grade (means of 37,15 percent for grade I, 44,49 percent for grade II, and 57,81 percent for grade III) and was significantly superior in recurrent meningiomas (46,19 percent vs 32,29 percent of non recurrent). The cut off of 40 percent became statistically useful to separate the benign meningiomas (grade I) from the non benign (grade II and III) and the recurrent tumors from the non recurrent. In this way, a labelling index of p53 protein equal or superior to 40 percent can indicate the possibility of a higher grade in histologically ambiguous cases or a higher risk to develop recurrencies in meningiomas of a particular histological grade (specially in benign tumors)

Lipomatous metaplasia occurring within meningiomas--two case reports.

Lipomatous meningiomas have recently been described as rare well defined variants of meningiomas characterized by meningothelial cells which undergo a metaplasia to adipocytes. Presence of intratumoral fat can sometimes cause confusion in preoperative radiological diagnosis. We report two such histologically unusual cases of meningiomas with significant adipose tissue metaplasia.

Meningiomas and hormonal receptors: immunohistochemical study in typical and non-typical tumors

The authors assessed 116 cases of meningiomas classified as typical, atypical and anaplastic and they used an immunohistochemical technique for estrogen and progesterone receptors attempting to determine if there is any difference between typical and non-typical tumors in relation to hormone receptors. The immunohistochemical technique to estrogen receptors was negative in all meningiomas studied. Progesterone receptors were detected in 58.3 percent of typical, and in 48.2 percent of non-typical meningiomas. This difference was not statistically significant. However, individually considering the criteria used for selection of non-typical tumours, those that concurrently displayed brain invasion and increased mitotic activity or necrosis, as well as the summation of those three features, were predominantly negative for progesterone receptors (respectively p=0.038; p=0.001; and p=0.044). The authors conclude that estrogen receptors were not present in meningiomas; that progesterone receptors in isolation are not enough to predict a higher tumoral malignancy but can be useful associated with other histological features.

Secretory meningioma: a case report with histopathological, immunohistochemical and ultrastructural analysis

Secretory meningioma have been described as a distinct variant of meningioma based on their histologic, immunohistochemical and ultrastructural features of epithelial and secretory differentiation of meningothelial cells with accumulation of secretory material in the form of hyaline inclusion. Secretory meningioma is also a benign tumor having similar biological behaviour to that of typical meningiomas: hence, it is important for it to be recognized and diagnosed correctly to avoid unnecessary radiation and chemotherapy. Here we present a case of secretory meningioma with typical morphologic features. The patient was a 56-year-old woman with bilateral visual disturbance. A well-circumscribed mass was present in the left frontal lobe of cerebrum with surrounding edema. The tumor was composed of whorls of meningothelial cells and abundant intra- and extracellular eosinophilic hyaline inclusions which showed immunoreactivity for epithelial membrane antigen(EMA) and carcinoembryonic antigen(CEA). Ultrastructural features also supported epithelial and secretory differentiation of tumor cells.