LAUSR

Intradural extramedullary spinal tumors are mostly benign and rarely malignant. Angiosarcoma is a rare malignant vascular tumor and occurs predominantly in soft tissues. Here we report an intradural extramedullary spinal tumor suspected as being an angiosarcoma. A 47-year-old woman was referred to our hospital with a complaint of numbness and acute progression of paralysis of both lower limbs. Neurological examination of the patient at admission revealed analgesia in the lower limbs and anus bilaterally, and complete motor paralysis of the lower muscles bilaterally. Magnetic resonance imaging (MRI) showed an intradural mass located from T12 to L2 and compressing the spinal cord (Fig. 1). Based on these findings, an intradural hemorrhagic lesion due to an arteriovenous fistula or tumor was suspected. Emergency surgery consisting of a laminectomy and durotomy from T12 to L2 was conducted and a dark red mass was seen in the subarachnoid space (Fig. 2A). We performed a gross total resection (Fig. 2B). After surgery, complete paralysis of lower limbs remained. Histopathological findings showed atypical nuclei with proliferation of blood vessels (Fig. 3A, B). Cluster of differentiation (CD) 31 and 34 antigen was positive (Fig. 3 C, D). S-100, epithelial membrane antigen, and glial fibrillary acidic protein staining were negative. Ki-67 was 10%20%, but few mitotic cells were seen. Initial diagnosis was hemangioma. Two weeks postoperatively, MRI showed the mass was mostly resected, but a small mass remained below the conus medullaris (Fig. 4A, B). Imaging studies at this time showed no tumor on the cranial side above Th12. Hemangioma was diagnosed at that time, so conservation and follow-up were chosen. Five weeks postoperatively, MRI showed the mass had expanded and cerebrospinal fluid (CSF) dissemination was seen at C1 and L5 (Fig. 4C, D). A malignant tumor was suspected clinically and histopathology was reviewed. Spindle cells were seen in the stroma, but not in the vascular endothelium (Fig. 3A, B). CD31 and 34 antigen staining was limited to vascular endothelial cells, and not seen in stromal cells (Fig. 3C, D). Pathology found stromal tumors of unknown differentiation with a proliferation of blood vessels. Ultimately, an angiosarcoma was suspected by the clinical course, but a definitive diagnosis could not be made. The patient already had numerous disseminated lesions, and surgical resection was not an option. Radiation therapy to the whole brain and spinal cord was performed. However, MRI after radiotherapy showed the mass had expanded at the cervical spine (Fig. 4D). Chemotherapy was not chosen because durability was limited. The best supportive care was chosen, but 6 months postsurgery, the patient died of respiratory muscle failure. To our knowledge, this is the first report of a primary intradural extramedullary spinal tumor suspected as an angiosarcoma, which usually occurs predominantly in the soft tissue of the head and neck. Primary spinal angiosarcomas have seldom been reported. Moreover, origins were all