Spinal Hemangiopericytoma Which Needed Intraoperative Embolization due to Unexpected Bleeding
A 21-year-old man visited complaining of neck pain and a tingling sensation in both hands. The intensity of neck pain had progressed over 1 year. The tingling sensation in the hands had developed 1 month prior and had worsened. Motor function and reflexes did not decrease. His magnetic resonance (MR) images revealed 2.5-cm well-circumscribed ventral IDEM mass at the level of C1-2 (). The mass showed iso-signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The lesion was homogenous and vividly enhanced with intravenous administration of gadolinium. Small cystic components were seen on T2-weighted images. The tumor did not expand or erode spinal canal or soft tissue. The tumor did not reveal calcification, adjacent bone erosion, and multilobulated lesions. No additional lesions were identified including brain, abdomen, and pelvis. Our presumptive diagnosis at preoperative state was meningioma, but schwannoma, and neurofibroma were also considered.\nThe patient underwent left hemilaminectomy at C1, left partial hemilaminectomy at C2, and partial resection of the foramen magnum. When the dura was opened, an IDEM tumor was placed behind spinal accessary nerves. The plane between the spinal cord and the mass placed well defined, and the flesh-red tumor was observed (). The tumor was partially exposed only after some accessary nerves had been cut. Because of narrow surgical field, we planned internal debulking first. While performing internal debulking by ultrasonic aspirator to remove the ventral IDEM tumor, unexpected tumor bleeding developed and was difficult to stop. Tumor bleeding could not be controlled by bipolar coagulator, and was stopped after compressing the lesion using microfibrillar collagen (Avitene™) for some minutes. It is difficult to find feeding arteries because of narrow surgical field. We halted the surgery and checked the spinal angiography at the angiography suite, which revealed two major feeders of the deep cervical branch from the vertebral artery (). Two main feeders were embolized by titanium coil or particles. After endovascular embolization of the feeder vessels, the tumor resection was resumed. The tumor was completely removed with minimal bleeding. The patient had a fast postoperative course, and the tingling sensation in his hands and his neck pain disappeared. He was discharged without symptoms and has been recurrence-free for the past 1 year ().\nA gross specimen revealed a nodular mass of soft tissue measuring 2×2 cm. The cut surface of the mass was reddish yellow. Hematoxylin and eosin staining showed a highly cellular neoplasm growing in patternless sheets and with high mitotic activity. There was proliferation of the tumor cells with oval nuclei, and the tumor was surrounded by abundant blood vessels resulting in the "staghorn" appearance typical of hemangiopericytoma (). After immunostaining, the tumor cells were negative for CD34 and epithelial membrane antigen. On the basis of these findings, we made a final diagnosis of hemangiopericytoma.