Venous ectasia preceding intra-tumoral hemorrhage in a case of gliosarcoma with transverse sinus involvement.

Although intratumoral hemorrhage is common in patients with malignant brain tumors, reports on its clinical course are scarce. This report presents a rare case of a patient with intratumoral hemorrhage with gliosarcoma invading the venus sinus. This invasion and a small draining vein were observed at diagnosis. Magnetic resonance imaging performed 1 week later showed new-onset venous ectasia, which caused intratumoral hemorrhage. This case provides insight into the mechanisms underlying intratumoral hemorrhage and highlights the emergence of new intratumoral vasculature as a potential warning sign for hemorrhage.