Medulloblastoma at the cerebello-pontine angle resembling vestibular schwannoma: A case report and review of the literature

Abstract

Cerebello-pontine angle (CPA) tumors account for only less than 10 % of intracranial tumors, it usually affects children at a young age with the midline being the most favorable location. Our adult patient demonstrated a very unusual site for medulloblastoma at the CPA. Less than 50 cases all around the world have been reported in the English literature for Medulloblastoma to be located at the CPA, and most of them in pediatric age group. We report a 43 year old female patient who presented to our neurosurgical ward in Jerusalem with a 4 months history of progressive decreased hearing at the left side, accompanied with tinnitus, dizziness, and imbalance on walking. Medulloblastoma at the CPA was one of the differential diagnosis and was confirmed at our histopathology unit after gross total resection of the tumor, the surgery followed by radiotherapy and the patient was well after 9 months after procedure. MB-CPA is a relatively rare tumor, and the early diagnosis make a difference in the management, prognosis, and outcomes, so it should be considered as a differential diagnosis of a lesion of the CPA.

Keywords: Brain tumor; Case report; Cerebello-pontine angle; Medulloblastoma; Posterior fossa.

Fig. 1

Pre-operative T1 weighted MRI axial cut with GAD showing a huge left CPA enhancing, heterogeneous rounded lesion with a mass effect over the brain stem and cerebellum surrounded by vasogenic edema.

Fig. 2

Post-operative Brain CT scan showing a complete resection of the left-sided CPA tumor with minimal hematoma at site of surgery.

Fig. 3

20×: INI-1 retained nuclear positivity.

Fig. 4

Cellular tumor composed of undifferentiated cells consists of small round to carrot shaped uniform cells with hyperchromatic nuclei and wispy cytoplasm, with distinct fibrillary background.