Brainstem cavernomas: a surgical challenge / Cavernomas de tronco: desafio cirúrgico

Objective: The authors show their experience with brainstem cavernomas, comparing their data with the ones of a literature review. Methods: From 1998 to 2009, 13 patients harboring brainstem cavernomas underwent surgical resection. All plain films, medical records and images were reviewed in order to sample the most important data regarding epidemiology, clinical picture, radiological findings and surgical outcomes, as well as main complications. Results: The mean age was 42.4 years (ranging from 19 to 70). No predominant gender: male-to-female ratio, 6:7. Pontine cases were more frequent. Magnetic resonance imaging was used as the imaging method to diagnose cavernomas in all cases. The mean follow-up was 71.3 months (range of 1 to 138 months). Clinical presentation was a single cranial nerve deficit, VIII paresis, tinnitus and hearing loss (69.2%). All 13 patients underwent resection of the symptomatic brainstem cavernoma. Complete removal was accomplished in 11 patients. Morbidity and mortality were 15.3 and 7.6%, respectively. Conclusions: Cavernomas can be resected safely with optimal surgical approach (feasible entry zone) and microsurgical techniques, and the goal is to remove all lesions with no cranial nerves impairment.

Objetivo: Os autores mostram sua experiência com cavernomas de tronco cerebral, comparando seus dados com os de uma revisão da literatura. Métodos: De 1998 a 2009, 13 pacientes com cavernoma de tronco cerebral foram submetidos a ressecção cirúrgica. Todos os filmes, prontuários e imagens foram revisados para exposição dos dados mais importantes, como epidemiologia, detalhes clínicos, achados radiológicos e resultados cirúrgicos, bem como as principais complicações. Resultados: A média de idade foi de 42,4 anos (variação de 19 a 70). Não houve predominância de gênero na taxa masculino versus feminino, 6:7. Os casos pontinos foram os mais frequentes. Ressonância nuclear magnética foi o método de imagem para o diagnóstico de cavernomas em todos os casos. A média do acompanhamento foi de 71,3 meses (variação de 1 a 138 meses). A apresentação clínica mais frequente foi a paresia do VIII nervo craniano, tinitus e perda auditiva (69,2%). Todos os 13 pacientes com cavernomas de tronco sintomáticos foram submetidos à ressecção cirúrgica. A remoção total foi realizada em 11 pacientes. A morbidade e a mortalidade foram de 15,3 e 7,6%, respectivamente. Conclusão: Os cavernomas podem ser seguramente ressecados por meio de acessos cirúrgicos ideais (zonas de entrada seguras) e técnicas de microcirurgia, sendo que o objetivo é remover toda a lesão sem o comprometimento dos nervos cranianos.

Medulloblastomas: new directions in risk stratification.

Medulloblastomas (MBs) are the most common malignant brain tumors in children. Current therapeutic approaches combine surgery, radiotherapy, and chemotherapy. Although, there has been significant improvement in long-term survival rates, the tumor remains incurable in about a third of patients while cognitive deficits and other sequelae of therapy are common among long-term survivors. Hence a major challenge remains to differentiate high-from low-risk patients and to tailor therapy based on the degree of biological aggressiveness. A clinical risk-stratification system has been widely used in MBs based on age, extent of resection and the Chang staging system. However, recent reports indicate that these clinical variables are inadequate methods of defining disease risk. This has prompted search for new markers for MB stratification. Recent studies indicate that the classification of MBs according to profiles of histopathology and molecular abnormalities possibly help better risk-stratification of patients, thereby rationalizing approaches to therapy, increasing cure rate, reducing long-term side effects and developing novel therapeutic strategies. The most accurate outcome prediction till date has been obtained through microarray gene expression profiling. In this article, the current histopathological classification and the recent advances in molecular genetics of MBs are reviewed. Global efforts to translate this knowledge of disease biology into clinical practice especially as outcome predictors are highlighted.