[A case report of neoplastic aneurysm due to metastatic choriocarcinoma].

A twenty-year-old female, who had multi-agent chemotherapy for eighteen months after surgical resection of a choriocarcinoma originating from the left adnexa, was hospitalized because of a cerebrovascular accident. Her complaints were unconsciousness, generalized convulsion and left hemiparesis. Although both plain and contrast enhanced CT scans demonstrated only acute subdural hematoma in the right frontoparietal region associated with midline shift, no tumor shadow was recognized over the cortex or intraparenchymally. A carotid angiogram revealed a large and irregularly shaped aneurysm at a peripheral branching of the angular artery. Evacuation of the hematoma, resection of the aneurysm and revascularization for the defect of the parent artery by transplantation of a part of STA by means of microsurgical anastomosis were done at an emergency operation. Nevertheless the graft did not prove to be patent on the post-operative angiogram. Due to retrograde filling of the distal portion of the angular artery through collateral channels, the patient has been completely free of neurological deficit and her performance of daily activities has been excellent. No appearance of other intracranial metastasis of the tumor has been detected for six months thereafter. Histological examination of the resected aneurysm demonstrated that choriocarcinoma composed of cytotrophoblasts and syncitiotrophoblasts filled the lumen of the aneurysm. The van Gieson's staining clarified the invasion of the tumor into the vascular wall causing disruption of lamina elastica beneath the fairly intact adventitia. Microscopic findings of the specimens taken from adjacent brain tissue and overlying dura mater confirmed absence of metastatic lesion in them.(ABSTRACT TRUNCATED AT 250 WORDS)