Two cases of epithelial
cyst are reported. Case 1. A 68-year-old female visited our hospital with a complaint of decreased visual acuity, 0.04 in the left eye, in September 1986. Visual field examination showed
bitemporal hemianopsia. CT scan demonstrated nonenhancing cystic lesion involving the suprasellar region. By a right frontotemporal
craniotomy, the
suprasellar cyst was explored. The wall of the
cyst was partially removed to relieve pressure against both optic nerves and chiasma. Histologically, the
cyst wall was lined with a single layer of non-ciliated cuboidal epithelium. Electron microscopic study revealed a number of microvilli, continuous basement membrane and desmosomes. Case 2. A 40-year-old female was admitted to our hospital because of sensory disturbance in the left hand for several years. She had an episode of convulsive seizure with a
loss of consciousness. Neurological examination revealed
hypesthesia of the left hand. CT scan showed non-enhancing right frontoparietal cystic lesion compressing the right lateral ventricle to the left. By a right frontoparietal
craniotomy, the cystic lesion was explored. The
cyst existed beneath an arachnoid membrane and contained CSF-like clear fluid. The
cyst wall was resected, as far as possible, to obtain communication with normal subarachnoid CSF space. Histologically, by light and electron microscopic study, the
cyst was considered to be an epithelial
cyst. A correct diagnosis is difficult because other cystic lesions such as
arachnoid cysts and
craniopharyngioma are of similar low density and appear the same on CT scan. It is impossible to diagnose such an epithelial
cyst by relying on neuroradiological study alone.(ABSTRACT TRUNCATED AT 250 WORDS)