Surgical treatment of brain tumor coexisted with intracranial aneurysm--case series and review of the literature.

Coexistence of brain tumor and intracranial aneurysm was previously considered as an uncommon phenomenon. Actually it is not rare in neurosurgical procedures, and its incidence rate may be underestimated. Furthermore, there remains a lack of consensus regarding numerous aspects of its clinical management. We performed a retrospective study of 12 cases of coexistent brain tumor and intracranial aneurysm in our database. Then a systematic PubMed search of English-language literature published between 1970 and 2012 was carried out using the keywords: "brain tumor" and "intracranial aneurysm" in combination with "associate" or "coexist." A consensus panel of neurosurgeons, anesthetists, interventional neurologists, and intensivests reviewed this information and proposed a treatment strategy. In the majority of patients, clinical symptoms were caused by tumor growth, whereas aneurysm rupture was seen only in a few cases. Meningioma was the commonest tumor associated with aneurysm. In most patients, both lesions occurred within the adjacent area. Treatment of both pathologies in one session was performed in most patients. All of our patients were alive within the period of follow-up. Coexistence of brain tumor and intracranial aneurysm may be a coincidence. The treatment strategy should be designed according to the conditions of tumor and aneurysm, locations of both lesions, and pathologic nature of tumor.