[Diffuse Astrocytoma with Pilomyxoid Features Presenting as Intratumoral Hemorrhage:A Case Report].

: Hemorrhagic low-grade glioma(LGG)without malignant transformation is rare, accounting for less than 1% of cases. To the best of our knowledge, hemorrhagic LGG with an arteriovenous(AV)shunt has not been reported. We report the case of 17-year-old man with LGG with an AV shunt. He presented to our hospital with seizure. Computed tomography(CT)demonstrated a hypodense lesion with mass effect in the right frontal lobe. T1-weighted images(WI)and T2WI on magnetic resonance imaging(MRI)revealed acute-onset hemorrhage in the right frontal lobe. Furthermore, a ring-enhancing lesion was noted on gadolinium(Gd)-DTPA T1WI, and an AV shunt was found in the same region on angiography. Gross total tumor resection was performed. The pathological diagnosis was diffuse astrocytoma with pilomyxoid features(WHO grade II). Without adjuvant therapy, no residual tumor was found on MRI at the 6-year follow-up examination. We treated a case of hemorrhagic LGG with an AV shunt. Intratumoral hemorrhage in LGG may occur and should be considered for the differential diagnosis.