["Colloid cyst" of the lateral ventricle--report of a case (author's transl)].

Colloid cyst is a relatively rare benign tumor which is usually found in the third ventricle. A patient who had a "colloid cyst" in his right lateral ventricle was experienced. A 33-year-old man had suffered from intermittent attacks of headache and vomiting for five months. On July 22, 1974, he was hospitalized to our clinic because of headache, memory and gait disturbance. At the time of admission his consciousness was clear but he had slight memory disturbance and urinary incontinence. Incipient papilledma was noted and the deep tendon reflexes of the lower extrimities were slightly accentuated. Lumbar puncture revealed a clear CSF and its pressure was within normal limit and the protein was 59 mg/dl. The plain skull films showed no abnormal findings. EEG showed an asymmetry of alpha-wave, and paroxysmal high voltage of slow wave was found in the right frontal area. Right cerebral angiography demonstrated an unrolling of the pericallosal arteries suggesting dilatation of the lateral ventricles. On the 9th hospital day, he suddenly began to complain of severe headache and became drowsy. Mannitol and hydrocortisone were injected intravenously without producing any remarkable effects. A ventricular drainage was done, and the patient recovered rapidly. A conray ventriculography revealed a round filling defect in the right lateral ventricle. A transventricular approach through a short linear incision in the right frontal cortex was preformed on the 25th hospital day. A cyst containing colloid substance, about 5x4 cm in size, was found to be attached to the medial wall of the right lateral ventricle anterior to the foramen of Monro. This cyst was almost completely removed. Histological findings revealed inner lining of epithelial cells, He died on the 25th postoperative day from bacterial meningitis. Autopsy confirmed the cyst to have originated from the right lateral ventricle. A review of the literature was made and the pathogenesis and diagnosis of this disease and the mechanism of development of the symptoms were discussed.