Ependymoma with “granular cell” features: Report of two cases

Abstract

We report two cases of ependymoma which showed prominent “granular cell” changes of the cytoplasm. The patients were a 7‐year‐old boy with a tumor in the cerebellum (case 1) and a 70‐year‐old man with a tumor in the frontal lobe (case 2). The tumor of case 1 showed a histopathological appearance of ependymoma containing many focal aggregates of large polygonal cells in which the cytoplasm was stuffed with numerous eosinophilic granules. The tumor of case 2 predominantly showed the features of papillary ependymoma, and some tumor cells were swollen and contained similar eosinophilic granules. Intracytoplasmic granules in both tumors were immunoreactive for GFAP and ubiquitin, but not for epithelial membrane antigen, CD68 or mitochondria. Ultrastructurally, they were found as aggregates of membrane‐bound, electron‐dense, globular structures. Karyotypic analysis of the tumor in case 1 demonstrated 2, 11 and 12 trisomies. Intracytoplasmic eosinophilic granules occasionally occur in astrocytic and oligodendroglial neoplasms, but an appearance of similar granules is very rare in ependymoma. The two cases presented here may represent a new histopathological variant of ependymoma, and the term “granular cell ependymoma” is appropriate for them.

An 11 Year Old Child with a Right Parieto‐Occipital Lesion

“…. Two additional cases have been reported recently . The first two cases reported by Yang and the first case described by Shintaku share some clinical and pathological aspects with our case.…”

“…Two additional cases have been reported recently . The first two cases reported by Yang and the first case described by Shintaku share some clinical and pathological aspects with our case. All cases affected pediatric patients and two, as our case, were hemispheric (frontal lobe), while the third case was localized in the posterior fossa.…”

“…If the granular cell areas or the granular cell ependymomas have specific molecular features, it is yet to be determined. The only case studied cytogenetically presented a 49, XY (+2, +11, +12) karyotype but it is not clear whether these changes were specific for the granular cell component or for the whole tumor .…”

Oligodendrogliomas with Abundant Refractile Eosinophilic Granular Cells

“…This risk is especially prudent considering pathologists' collective familiarity with granular cell astrocytoma 4 , and in cases lacking other classic morphologic features of oligodendroglioma. Eosinophilic granular inclusions have also been reported in ependymoma 5 , medulloblastoma 6 , and schwannoma 7 . Yoshida et al 2 re-examined 102 gliomas and found some rEGC in 9% of grade II oligodendrogliomas, 11% of grade II oligo-astrocytomas, 82% of grade III oligodendrogliomas and 76% of grade III oligo-astrocytomas.…”