Schwannomas of peripheral nerves are the most common benign tumors in this location; it has specific radiologic and histologic features that enable its fundamental distinction of neurofibromas. Given its importance in neurosurgical practice, known radiologic and histologic criteria must be updated regarding this disease entity, as well as its therapeutic strategy and results obtained with it. This article reviews this subject, followed by a case report considered out of the ordinary, in which the tumor was located in the sciatic nerve in a patient with neurofibromatosis type 1, treated by microsurgical resection, which evolved favorably.

Meningiomas are among the most common central nervous system tumors, with an incidence that ranges from 15% to 40% of intracranial tumors. Of these, only 0.5% to 3% are intraventricular, and the rarest of them occurs in the fourth ventricle.Fourth-ventricle meningiomas originate generally from the choroid plexus and have no dural adhesions. Most often, they manifest in young patients, around 41 years of age, with a possible predominance in females, through intracranial hypertension and cerebellar syndromes. The treatment consists of surgical resection, which commonly presents good results due to the characteristics of the tumor. So, for better preoperative planning, the radiological differentiation of the most frequent tumors in this location is important.The most common histologic subtypes are fibroblastic and meningothelial, both grade I according to the World Health Organization (WHO), although there are reports of tumors of grades II and III.We report a case of meningioma of the fourth ventricle operated in our institution, and we have conducted a literature review, through which we found that 57 cases have been reported so far, with the first one reported in 1938.

ResumoCraniofaringiomas são tumores histologicamante benignos, extrínsecos ao parênquima cerebral. Visando ao controle da doença, preconiza-se, como tratamento padrão, a tentativa de ressecção completa, meticulosamente planejada com vistas a preservar as funções habituais do paciente. Outras formas de terapias podem ser utilizadas como alternativas ou como adjuvantes à cirurgia. Considerando-se que muitos craniofaringiomas apresentam componente cístico, a utilização de cateteres posicionados no interior do lúmen cístico para aplicação de agentes quimioterapêuticos, como o interferon alfa (IFNa), tem-se mostrado promissora. Administração intratumoral de 3 milhões de unidades de IFNa em dias alternados, totalizando doze ciclos, tem sido utilizada empiricamente. Relatamos o caso de uma paciente de 12 anos de idade, com diagnóstico de craniofaringioma de predomínio cístico, tratada no Hospital de Câncer de Barretos (HCB) utilizando a aplicação de IFNa semanalmente, que apresentou evolução favorável. AbstractCraniopharyngiomas are histologicaly benign tumors, whose ideal brain treatment requires its complete surgical resection, while preserving most of the usual functions of the patient. Due to the complexity of the surgical procedure, related to location (surrounded by paraselar structures), it is often difficult to achieve its complete resection. Thus, alternative therapies have been reported, including the use of intracystic IFNa on alternate days. We report the case of a 12 year-old female, diagnosed Recebido

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