[Ependymal cyst--case report].

An eleven-month-old male infant with an ependymal cyst is reported. He was born after full-term pregnancy and vacuum extraction. His growth and development was somewhat retarded and he could control his head at the age of five months. He was admitted to our hospital because of the enlargement of his head and the paretic right upper limb. On admission he was found to be a well-nourished infant with the head circumference of 54.5 cm and the height of 75.5 cm. Physical examination disclosed slight weakness in the right upper extremity but no signs of increased intracranial pressure. Computed tomography (CT) revealed a huge low density area in the left frontoparietooccipital region which extended to the right across the midline. Another low density area was seen in the quadrigeminal cistern. CT findings also suggested an association with agenesis of the corpus callosum. The huge supratentorial cyst was isolated from the ventricles and subarachnoid space, which was shown by administration of metrizamide into the cyst. Carotid angiograms showed displacement of both anterior cerebral arteries to the right, which were dissociated from each other. This fact and an association with agenesis of the corpus callosum supported the idea that the cyst originiated in the interhemispheric fissure and expanded into both hemispheres. Cyst fluid was watery clear and protein and sugar contents were 13 mg/dl and 56 mg/dl respectively. The patient underwent a left frontal craniotomy and partial removal of the cyst wall was performed to make a communication with the ventricle. His postoperative course was uneventful and the weakness of the right upper extremity gradually improved.(ABSTRACT TRUNCATED AT 250 WORDS)