Cerebellar oligodendroglioma in adult patient: case report

Introduction: A 36-year-old male sought care due to dizziness and loss of balance 30 days ago. At the physical examination, left dysmetria, gait ataxia and dysarthria were identified. Motor strength, sensitivity and reflexes, were preserved. Magnetic resonance imaging (MRI) was performed, which revealed a massive solid-cystic lesion of 5.3 × 5.1 cm, with centers of calcification on the left cerebellar hemisphere, affecting the vermis and small part of the right cerebellar hemisphere bordered by perilesional edema. In addition, it had a compressive effect on the IV ventricle, conditioning hydrocephalus, and herniation of the tonsils. Due to the possibility of deterioration by hydrocephalus or brainstem compression, the patient underwent surgery. Suboccipital craniectomy and complete resection of the lesion were performe. In addition, an external ventricular derivation (EVD) was installed in the occipital horn. The immunohistological analysis of lesion revealed grade II oligodendroglioma with extensive dystrophic calcification. After the procedure, there was no improvement of the cerebellar symptoms already installed, but hydrocephalus was controlled, and no new deficits were developed.

Discussion: Oligodendrogliomas are malignant glial cell tumors and account for 4–5% of all primary brain tumors. Most are supratentorial and only 7% are found in the posterior fossa. In addition, when infratentorial, most occur in pediatric patients. The symptoms attributed to oligodendroglioma are progressive and strictly related to its location. When it occurs in the posterior fossa, the symptoms observed are loss of balance, gait ataxia, dysmetria, dizziness and nausea. Findings on imaging may be characteristic but the immunohistological assay is necessary to confirm the pathology. The diagnosis is suggested preoperatively when intratumoral or peritumoral calcification is seen (up to 90% cases), and peritumoral edema and mass effect are usually minimal despite the size of the tumor. The treatment is the surgical excision with or without adjuvant radiation therapy based on multiple prognostic factors. Infratentorial tumors may be more aggressive than supratentorial ones.

Conclusion: Our case consists in a very rare presentation of oligodendroglioma. Although it is usually located in supratentorial position, the posterior fossa must be kept in mind, mainly when it present typical radiologic signs

No conflict of interest has been declared by the author(s).