Intraparenchimal mesencephalic cyst which occurs in lateral part of the mesencephalon is very unusual. In addition to describe this case, the authors also reviewed other brainstem cysts described in literature and briefly discus concept of their origin.
They report a patient with cyst in right part of the mesencephalon of a 10-years old girl presenting symptoms of increased intracranial pressure and local compression. We discuss the clinical presentation, radiological investignation, pathological features and surgical treatment options for this lesion.
First surgical intervention was fenestration cysts, second ventricular-peritoneal shunt and third stereotactic navigation cysto-cysternostomo mesencephalic cyst with ponotocerebelar subarachnoidal space. Biochemical examination showed fluid in cyst and patohistological examination showed fibrilar connective tissue without epithelial cell of the wall cysts.
Eight years later she is in good condition. Surgical resection or total extirpation cyst like that is not recommended 1).
A 66-year-old woman presented with a 3-year history of predominantly right-sided blepharospasm and a 1-year history of progressive predominantly left-sided hemiparkinsonism manifested by a left upper extremity resting tremor and left-sided bradykinesia. Magnetic resonance imaging of the brain revealed a large right mesencephalic cyst with mass effect. Positron emission tomography revealed bilateral striatal hypometabolism consistent with nigrostriatal dopaminergic dysfunction. The association of predominantly ipsilateral blepharospasm and predominantly contralateral hemiparkinsonism is very rare, and its association with a posterior fossa space-occupying lesion has been reported only once. This is the second report of such an association and the first description of adult-onset symptomatology 2)
LU AT, YUEN TG, BASSLER TJ. Mesencephalic cyst in fourth ventricle causing obstructive hydrocephalus. Bull Los Angel Neuro Soc. 1962 Jun;27:79-86. PMID: 14467022.