A associação de malformações vasculares intracerebrais com neoplasias cerebrais primárias é rara. Mais comumente encontrados são os aneurismas arteriais intracranianos com neoplasias primárias. Relatamos dois casos de malformações vasculares associadas a neoplasias cerebrais primárias, com estudo histopatológico e imuno-histoquímico.

Foram estudados dois meningiomas meningoteliais obtidos em cirurgia com inclusões hialinas ou corpos pseudopsamomas. Ambos mostraram expressão de antígeno carcinoembriônico e citoqueratina em células circundando corpos hialinos. Havia difusa imunoexpressão de vimentina e antígeno epitelial de membrana exceto nas células com inclusões hialinas. Ambos se acompanhavam de intenso edema cerebral. Um dos casos apresentava tumores múltiplos, provavelmente meningiomas. É importante não interpretar esta variante de meningioma como neoplasia metastática, o que pode resultar em tratamento paliativo de um tumor potencialmente curável.

Miastenia grave é doença neuromuscular caracterizada por excessiva fatigabilidade da junção muscular e envolve, particularmente, músculos inervados por nervos cranianos. Acredita-se que o defeito esteja localizado na junção neuromuscular. Os autores estudaram os achados histoquímicos e e morfométricos em 4 pacientes com miastenia grave mostrando que as fibras do tipo II eram significativamente menores que as fibras do tipo I.

As alterações histológicas de oito casos de meduloblastoma desmoplásico são investigadas e comparadas às do meduloblastoma clássico. As neoplasias histológicamente menos malignas foram as do grupo do meduloblastoma desmoplásico, caracterizadas por menor frequência de necrose, menor índice mitótico e alterações nucleares leves.

Paciente operado de tumor intramedular que evoluiu para o óbito, cuja necrópsia revelou presença de germinoma intramedular e germinoma supra-selar remanescente de tratamento cirúrgico e radioterápico realizado 11 anos antes. São discutidas a etiologia e a conduta cirúrgica e radioterápica.

Objective: To demonstrate that mild hypothermia can be a protective element when an ischemic onset occurs in rabbit brains. Methods: A rabbit model of focal ischemia was used to test the protection provided by mild hypothermia regionally produced by means of the placement of ice bag on the scalp of a hemicranium which has had previously its bone removed. Twenty New Zealand White rabbits were divided into two groups as follows: (A) a control group where an ischemic lesion was produced by coagulation of the middle cerebral artery and (B) a brain protected group where mild hypothermia was provided during 80 to 100 minutes after the same ischemic lesion. The brains slices were stained with 2,3,5-Triphenyletrazolium (TTC). The sections were photographed with a digital camera and the infarct volume was measured through a computer program. Results: The average of infarct volume was 70.53 mm³ in the control group. In the protected group, the average of infarct volume was 41,30 mm³ only in five animals. Five animals of this group did not demonstrate macroscopically and microscopically infarct area. Conclusions: We concluded that mild hypothermia regionally produced may protect ischemic brains of rabbits.

PURPOSE: To evaluate the immunohistochemical expression of p16, Ki-67, p53 and Bcl-2 proteins in gastrointestinal stromal tumors (GIST); to assess the possible association between these variables and clinical and histopathological factors of cancer; and to check for prognostic value of these variables (survival and recurrence). METHODS: A sample of 55 patients treated surgically for GIST in three hospitals was studied. The surgically excised tumors were confirmed as GIST by KIT, vimentin, desmin S100 protein, CD117, 1A4 and CD34 assessment in paraffin blocks. RESULTS: Only 9 (16%) cases of GIST were positive for p53, p16 was positive among 43.6%; 80% of GISTs showed staining for Bcl-2. The proliferative index (expressed as the proportion of positive cells) assessed by immunohistochemical expression of Ki-67 was high in 49% of cases. Elevated Ki-67 scores were associated to high histological grade (p=0.0026) and mitosis index, MI (p=0.0001). High Ki-67 index was associated to death. Expression of p53, p16 and Bcl-2 did not correlate to morphological or clinical variables. CONCLUSIONS: Ki-67 immunohistochemical evaluation should be included in preoperative evaluation of GIST biopsies or surgical specimens as a prognostic tool for clinical staging; and all other proteins studied (Bcl-2, p53 and p16) did not play a role in GIST metabolic or carcinogenic process, remaining without prognostic value.