Macroscopic and microscopic appearance of the tumor. (A) The firm tumor was easily dissected from the surrounding brain tissue and had a smooth tan-yellow glistening cut surface. (B) Microscopic examination revealed a paucicellular tumor consisting of predominantly fusiform cells in a myxoid background. There is moderate nuclear pleomorphism with a multinucleated cell in the center (hematoxylin & eosin). (C) The loose myxoid background stained positive for Alcian blue. (D) Immunohistochemical staining for CD34 is diffusely positive. (E) Electron microscopic examination showed stellate cells with long delicate processes and occasional multinucleation. (F) The extracellular material is abundant with clusters of collagen fibers. (Original magnifications: B-C, ×400; D, ×200; E, ×2000; F ×30000).