Distant dissemination of mixed low-grade astroblastoma-arteriovenous malformation after initial operation: a case report.

We present a rare case of low-grade astroblastoma coexisting with an arteriovenous malformation (AVM) underwent surgery two times in a 38-year-old man. After the first surgery, this case was reported as a mixed low-grade astroblastoma and AVM. The lesion was completely resected surgically along with AVM. The patient underwent postoperative radiotherapy. Twenty months later, MRI showed enhanced lesions in suprasellar, pineal region and multiple small lesions in the spinal cord, whereas completely no recurrent lesion at the primary tumor site. So, the patient rationally underwent surgical removal in suprasellar and pineal region. After the second surgery, this case was diagnosed as a high-grade astroblastoma. Cells from the second surgical specimens showed high MIB-1 index and an increased olig-2 index. In addition, it is not common for low-grade astroblastoma metastasis to suprasellar, pineal region and spine with completely no recurrence at the original primary tumor site. Therefore it is difficult to predict tumor behavior and patient's clinical outcome merely based on histologic features. The important issue is whether the AVM was thought to be the cause of poor progress of this tumor. More cases are needed to confirm this. Classification and histogenesis of this tumor is still debated. Lack of clinicopathological correlation makes the prognosis of this tumor unpredictable. Anyway, we should be very discreet to treat the astroblastoma, even for low-grade astroblastoma.