J Korean Med Sci.  2007 Sep;22(Suppl):S149-S153. 10.3346/jkms.2007.22.S.S149.

Intramedullary Clear Cell Ependymoma in the Thoracic Spinal Cord: A Case with Its Crush Smear and Ultrastructural Findings

• Kim NR
• Chung DH
• Lee SK
• Ha SY

• KMID: 1785805
• DOI: http://doi.org/10.3346/jkms.2007.22.S.S149

Abstract

Clear cell ependymoma was included in the World Health Organization classification of the nervous system in 1993, and all the reported cases, except for two in the spinal cord, were located in the brain, mainly in the supratentorial compartment. Astrocytomas outnumber ependymomas in the spinal cord, and the two entities partly share cytologic findings such as long, bipolar glial processes and oval to round nuclei resembling those seen in pilocytic astrocytoma. Here, we report the first Korean case of intramedullary clear cell ependymoma of the spinal cord, which is the third case situated in the spinal cord in the literature. The crush smear revealed round-to-oval nuclei with occasional nuclear eosinophilic inclusion and rare nuclear grooves. Cytoplasm had fluffy eosinophilic glial processes, and acellular fibrillary zone. On hematoxylin-eosin stain, oval to round tumor cells had large central nuclei with indistinct nucleoli and a moderate amount of clear cytoplasm, i.e. perinuclear halo, mimicking oligodendroglioma. Perivascular pseudorosettes and ependymal clefts were rarely found. In retrospect, perinuclear halo was absent on crush smears. Ultrastructurally, they had extensive surface microvilli and edematous cytoplasm filled with abundant glial filaments and microlumens with or without microvilli. Intercellular long cell junctions of the zipper-like zonula adherens type were found.

Keyword

Ependymoma, Clear Cell; Spinal Cord; Crush Smear; Microscopy, Electron

MeSH Terms

Aged
Ependymoma/metabolism/*pathology/ultrastructure
Female
Humans
Immunohistochemistry
Microscopy, Electron, Transmission
Spinal Cord Neoplasms/metabolism/*pathology/ultrastructure

Figure

• 

  Fig. 1 MR images of the thoracic spinal cord. A T1-weighted image demonstrates that the tumor is isodense (arrow).

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  Fig. 2 Touch preparation on H&E stain. Smear preparation with long glial processes and oval to round tumor nuclei. (A) Tumor cells show fibrillary cytoplasm and euchromatic round to vesicular nuclei. (B) Acellular fibrillary zones. (C) Intranuclear pseudoinclusions (left) and nuclear grooves (right).

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  Fig. 3 H&E stain. (A, B) Clear cells with round nuclei with perinuclear halo and eosinophilic cytoplasm. (C) Ependymal rosettes. (D) Nuclear pleomorphism.

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  Fig. 4 (A) The tumor cells show abundant cytoplasmic long processes containing intermediate filaments, microtubules, free ribosomes, rough endoplasmic reticulums (×5,400). (B) Cell junctions of zonula adherens type and abundant microvilli with rare cilia are found (×27,000).

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