Ependymoma Alongside Hereditary Paraganglioma-Phaeochromocytoma Syndrome Due to a SDHB Mutation: A Case Report

Abstract

Mutations in the SDHB gene cause a characteristic syndrome that includes paragangliomas (PGL) and phaeochromocytomas (PCC). Herein we present a rare case of an ependymoma in a patient with a germline SDHB mutation. A 41-year-old man with a positive family history of PGL/PCC syndrome was found to have the familial SDHB mutation. Screening imaging for paragangliomas revealed an incidental presumed ependymoma originating from the fourth ventricle. He was followed with serial imaging to assess for progression of the lesion. Due to slow, substantial growth of the tumour, and increasing symptoms which included diplopia, unsteadiness, and wide-based gait, he underwent a resection 5 years after the lesion’s identification. Following resection of the tumour, the pathology confirmed the tumour as a posterior fossa type B (PFB) ependymoma of the fourth ventricle. Unfortunately, on Day 26 post-operatively, the patient had a pulmonary embolism and died. His family consented to an autopsy, which revealed the presence of a clinically-silent pituitary neuroendocrine tumour (PitNET). Though ependymomas are not commonly seen in PGL/PCC syndrome, they can occur. This case represents the first molecularly-characterised ependymal tumour described in this tumour predisposition syndrome. Clinicians ought to be aware of the risk of ependymoma in patients with PGL/PCC syndrome and consider this tumour when conducting their screening and follow-up of asymptomatic SDHx mutation carriers.