Lipidized (foamy) tumor cells in a spinal cord ependymoma with collagenous metaplasia

• Published in: Acta neuropathologica Vol. 95; no. 4; pp. 421 - 425
• Main Authors: TAKAHASHI, H, GOTO, J, EMURA, I, HONMA, T, HASEGAWA, K, UCHIYAMA, S
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.04.1998; Springer Nature B.V
• Subjects: 2-Methylisoborneol; Biological and medical sciences; Cilia; Collagen; Collagen - metabolism; Cytoplasm; Ependymoma - metabolism; Ependymoma - pathology; Ependymoma - ultrastructure; Female; Filaments; Glial fibrillary acidic protein; Humans; Immunohistochemistry; Leukocytes (eosinophilic); Magnetic Resonance Imaging; Medical sciences; Metaplasia; Metaplasia - pathology; Microscopy, Electron; Middle Aged; Neurology; Nodules; Paraffin Embedding; Spinal cord; Spinal Cord Neoplasms - metabolism; Spinal Cord Neoplasms - pathology; Spinal Cord Neoplasms - ultrastructure; Surgery; Tumor cells; Tumors of the nervous system. Phacomatoses; Human; Immunohistochemistry; Nervous system diseases; Spinal cord; Lipids; Case study; Pathology; Metaplasia; Glioma; Ultrastructure; Collagen; Central nervous system disease; Tumor; Adult; Female; Diagnosis; Spinal cord disease; Tumor cell; Ependymoma
• ISSN: 0001-6322; 1432-0533
• DOI: 10.1007/s004010050819

We report a 49-year-old woman with a spinal cord ependymoma located in the thoracolumbar region. At surgery, a soft dark-grayish tumor, which contained a hard whitish area, was removed. The specimen was a moderately cellular tumor with a central core made up of collagen nodules poor in cellular elements. Many of the tumor cells possessed ground glass-like eosinophilic cytoplasm, and frequently foamy tumor cells were evident. Perivascular pseudorosettes, ependymal rosettes and canals were present, the latter being rare. Many tumor cells, including those with foamy cytoplasm, were positive for glial fibrillary acidic protein. Similar tumor cells were also seen among, and even within, the collagen nodules. The MIB-1 labeling index was 0.66%. Ultrastructurally, the frequent lipidized tumor cells were ependymal in nature; cytoplasmic 10-nm-wide filaments, and intracytoplasmic lumina and intercellular microrosettes lined by microvilli were evident. Cilia were very rare. We considered the present case to be an unusual, lipidized variant of ependymoma. The collagen nodules appeared to be produced by the tumor cells themselves.