The case of a 32-year-old Japanese man with an expansile supratentorial neurenteric cyst is described. The initial MRI revealed
a left frontal extraaxial mass lesion 20 mm in diameter that showed marked expansion to 32 mm and change in its signal intensity
13 months later. Fifteen months after his visit, the patient fell into status epilepticus and underwent surgery. The cyst
wall was excised, and the cyst content was totally removed. The cytology of the cystic content and pathological findings of
the cyst wall were compatible with the diagnosis of neurenteric cyst. Our literature search revealed that in 86% of the patients
with this lesion, the lesion was involved in the occurrence of epilepsy during the perioperative period. When a neurenteric
cyst is diagnosed, shunt surgery should be avoided to prevent migrating spread of neurenteric cells.
Key words Neurenteric cyst - Status epilepticus - Enlargement
Part of this work was presented at the 24th annual meeting of the Japanese Society for Brain Tumor Pathology on June 29, 2006,
in Okinawa, Japan. This work was supported by a grant (to I.T.) from the Education and Research Software Updating Program
of the Promotion an Mutual Aid Corporation for Private Schools of Japan.