Chondro-Osseous Metaplasia in Ependymoma: A Rare Histopathological Finding

Ali Alkhaibary,Makki Almuntashri,Ali H Alassiri,Salma Tarik Al Qutub,Fahd Alsufiani

doi:10.1155/2020/1528698

Abstract

Ependymoma is a circumscribed glioma composed of uniform glial cells with bland nuclei in a fibrillary matrix. It is characterized by the presence of perivascular pseudorosettes. Unusual histopathological findings have rarely been reported in ependymomas, 0.5% of all diagnosed cases. Such unusual and exceedingly rare histological findings include osseous or chondroid metaplasia. To the best of our knowledge, only 15 cases of osseocartilaginous ependymomas have been reported in English literature. We report a 3-year-old boy who presented with ataxia, vomiting, and headache for three months. Radiological imaging revealed a posterior fossa lesion. Histopathological examination of the lesion confirmed a posterior fossa ependymoma with chondro-osseous metaplasia. The present case outlines the clinical presentation, histopathological findings, and outcome of chondro-osseous metaplasia in ependymomas. To date, the etiology of chondro-osseous metaplasia in ependymomas remains uncertain. Further research exploring such phenomenon is of paramount importance to explain how these tumors develop.

Highlights

Ependymoma is a noninfiltrative glioma usually arising near the ventricular system or central canal
We report a case of ependymoma with chondro-osseous metaplasia by outlining the clinical presentation, histopathological features, and outcome
There was a focus of chondro-osseous metaplasia within the well-differentiated part of the tumor

Summary

Introduction

Ependymoma is a noninfiltrative glioma usually arising near the ventricular system or central canal. According to the WHO grading scheme, ependymomas are divided into three types These include myxopapillary ependymoma (WHO grade I), conventional ependymoma (WHO grade II), and anaplastic ependymoma (WHO grade III). Unusual histopathological patterns such as pigmented (melanotic) ependymomas, giant-cell ependymomas, ependymomas with extensive tumor cell vacuolization, and chondro-osseous ependymomas have been reported in the literature. These rare patterns are noted in only 0.5% of all diagnosed ependymomas [4]. We report a case of ependymoma with chondro-osseous metaplasia by outlining the clinical presentation, histopathological features, and outcome

Case Description

Discussion

Ethical Approval

Conflicts of Interest