Eosinophilic globules in a classic ependymoma: evidence of a possible secretory role

ABSTRACT

A number of neoplasms of the central nervous system can demonstrate diffuse eosinophilic globules, known to be secretory products of the corresponding cell type, but they have not been a salient feature in descriptions of classic ependymoma. Here, we present a case of a posterior fossa ependymoma demonstrating glassy PAS-positive, diastase-resistant, eosinophilic globules with light microscopic and ultrastructural features resembling Reissner fiber, the secretory product of the subcommissural organ. While there has been a single published description of an ependymoma with intra- and extracellular granulofibrillary material suggested to be evidence of secretory differentiation, ours is the first case to demonstrate diffuse eosinophilic globules in an ependymoma. The extent of globules allowed full study by electron microscopy to provide new insight into the secretory material and the surrounding structures. Our findings suggest that neoplastic ependymal cells can recapitulate the secretory capacity of the subcommissural organ.

KEYWORDS:

• Ependymoma
• secretory
• globules
• subcommissural organ
• Reissner fiber

Note

Age and gender may have been altered to protect patient anonymity, but the changes do not distort the scientific meaning of the findings.

Acknowledgments

We extend our sincerest appreciation to Steven Conlon (Duke PhotoPath Laboratory) for his technical assistance in the preparation of this manuscript.

Declaration of interest

The authors report no conflict of interest.

Informed consent

This case was deemed Exempt by the Duke University Hospital System Institutional Review Board (Protocol ID: Pro00104726).

Conflicts of interest

None

Additional information

Funding

This work was supported by the Department of Pathology and the Preston Robert Tisch Brain Tumor Center, Duke University School of Medicine, Durham, North Carolina, United States of America (G.Y.L.).