Spinal intramedullary ependymal cyst. Report of three cases.

Three cases of spinal intramedullary ependymal cyst, two at the thoracolumbar junction and one in the cervical spinal cord, are reported in women in their fifth to seventh decades. Neurological signs and symptoms were extremity dysesthesias, paresthesias, and weakness. Plain cervical and lumbothoracic x-ray films were normal for the patients' age. Magnetic resonance (MR) imaging demonstrated a rounded cystic intramedullary mass at the thoracolumbar junction in two cases and at C3-7 in one case. The signal intensity of the cyst contents approximated that of cerebrospinal fluid on T1- and T2-weighted images. Upon administration of gadolinium-diethylenetriaminepenta-acetic acid (Gd-DTPA), MR imaging showed no enhancement in the cyst wall or cavity. Myelotomy and cyst drainage were performed in each case, and the neurological status of each patient improved. The lining of the cyst was biopsied in one of the three patients undergoing surgery and was composed of a single layer of cuboidal cells supported by glial tissue. Periodic acid-Schiff staining of the tissue did not reveal a basement membrane. The findings in these cases suggest that the Gd-DTPA-enhanced MR imaging appearance of intramedullary spinal ependymal cyst is consistent and allows for accurate preoperative diagnosis with or without biopsy.