Reversible Hearing Impairment Due to Inferior Colliculi Compression by a Pineal Glial Cyst.

Pineal glial cysts associated with bilateral hearing impairment are very rare. Here, we present the case of a 13-year-old boy with a pineal cyst, which caused severe bilateral hearing impairment persisting from 6 years of age. When the patient was 6 years old, the bilateral hearing acuity was about 40 dB on audiometry. Upon admission to our otolaryngology department, his audiogram revealed a bilateral worsening of the hearing acuity (80 dB). Magnetic resonance imaging (MRI) revealed an abnormal pineal cyst with tectal compression from the left with hardly normal bilateral brainstem auditory evoked potentials (BAEPs). We obtained informed consent for exploratory surgery and employed the right occipital transtentorial approach for pineal cyst removal. Based on histological examination, we diagnosed a glial cyst of the pineal gland. At 12 months postoperatively, the patient's hearing improved, showing a bilateral hearing acuity of 40 dB on audiometry. Since the auditory pathway has both crossed and uncrossed fibers at the upper pons and midbrain level, compression at the lateral lemniscus or inferior colliculus level can cause bilateral hearing impairment. In the present case, there was a possible slow pineal cyst growth that eventually compressed the upper pons to the midbrain, lateral lemniscuses, or inferior colliculi from the left side, this eventually led to bilateral hearing impairment. These findings indicate that surgery can improve hearing acuity in patients with a pineal cyst associated with progressive hearing impairment.

Glial Cyst inside the Cerebellar Parenchyma: Case Report and Literature Review

Cystic lesions inside the brain parenchyma are a common pathological finding in the investigation of patients with suspicion of cerebral tumor. Histological diagnosis is important to guide the patient's treatment and follow-up, and to determine prognosis. Among patients diagnosed with cerebral cysts, most are located in the parenchyma above the tentorium. The authors describe the case of a patient who had been suffering from dizziness and balance disturbance for 4 months; the investigation identified a cyst inside the cerebellar right hemisphere. A surgical procedure was performed, and the biopsy microscopic analysis diagnosis was glial cyst.

Patologias intraparenquimatosas de características císticas são comumente identificadas em pacientes que estão sob investigação de neoplasias cranianas. Lesões císticas são mais prevalentes acima da tenda cerebelar, e o diagnóstico histológico é fundamental para determinar o tratamento, seguimento e prognóstico do paciente. Os autores relatam o caso de um paciente com sintomas de vertigem e alteração no equilíbrio dinämico de 4 meses de evolução, cuja investigação diagnosticou cisto intraparenquimatoso no hemisfério cerebelar direito. Procedeu-se com intervenção cirúrgica cujo diagnóstico histopatológico foi compatível com Cisto Glial