ABSTRACT
Pilocytic astrocytoma (PA) is a circumscribed neoplasia considered as a grade I astrocytoma by the World Health Organization. Its most common location is the cerebellum and it develops during the first two decades of the life. Prognosis is mostly excellent if gross-total resection can be achieved, with 10-year survival rates of up to 80%. Anaplastic or malignant transformation (MT) can rarely occur and is usually related to previous radiation. Spontaneous MT has exceptionally been reported. Histological criteria for diagnosis of MT are unclear, so no consensus exists. We present an atypical case of MT of a frontal PA without previous radiotherapy in a 28 years old patient. Also, we review the literature about prognostic factors of PA and discuss histological features that are considered as anaplastic or malignant in the PA.
Subject(s)
Astrocytoma/pathology , Cell Transformation, Neoplastic/pathology , Supratentorial Neoplasms/pathology , Adult , Astrocytoma/surgery , Humans , Male , Supratentorial Neoplasms/surgery , Treatment OutcomeABSTRACT
Pilocytic astrocytoma (PA) is a circumscribed neoplasiaconsidered as a grade I astrocytoma by the WorldHealth Organization. Its most common location is thecerebellum and it develops during the first two decadesof the life. Prognosis is mostly excellent if gross-totalresection can be achieved, with 10-year survival ratesof up to 80%. Anaplastic or malignant transformation(MT) can rarely occur and is usually related to previousradiation. Spontaneous MT has exceptionallybeen reported. Histological criteria for diagnosis ofMT are unclear, so no consensus exists. We present anatypical case of MT of a frontal PA without previousradiotherapy in a 28 years old patient. Also, we reviewthe literature about prognostic factors of PA and discusshistological features that are considered as anaplastic ormalignant in the PA (AU)
El astrocitoma pilocítico es un tumor bien delimitado,que según la clasificación de la OrganizaciónMundial de la Salud, se cataloga dentro del grupo de losastrocitomas de grado I. La localización más frecuentede esta neoplasia es el cerebelo y se manifiesta fundamentalmenteen las dos primeras décadas. Siempre ycuando se consiga una resección total, el pronóstico esmuy bueno, alcanzando una tasa de supervivencia del80% a los diez años. De manera excepcional, puedehaber casos de transformación anaplásica o maligna,normalmente asociados a radioterapia previa; se handescrito muy pocas situaciones de transformaciónespontánea. Existe mucha discusión a la hora de considerarlos criterios de malignidad desde un punto devista anatomopatológico. Presentamos un caso excepcionalde transformación anaplásica de un astrocitomapilocítico en un paciente de 28 años, al igual que revisamoslos criterios pronósticos de esta neoplasia y discutimoslos datos anatomopatológicos que se consideran deanaplasia o malignidad (AU)
