Paraganglioma of cauda equina.Clinicopathologic and ultrastructural studies of an unusual case

An unusual tumor of the cauda equina is presented. It was interpreted as being most likely a paraganglioma, although some of its features were reminiscent of an ependymoma. In addition to the characteristically dense core vesicles, globular skeins of cytofilaments resembling the bodies described in Pick's disease were also seen. CSF xanthochromia, the extreme vascularity of the tumor, and the presence of a clot adherent to it at the time of operation suggested that some of the patient's clinical manifestations were due to leakage of blood into the subarachnoid space.