CNS tumor
Ependymal tumors
Tanycytic ependymoma
Author: Eman Abdelzaher, M.D., Ph.D.
Topic Completed: 1 August 2012
Minor changes: 25 September 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Tanycytic ependymoma [title]
Table of Contents
Definition / general | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Electron microscopy description | Differential diagnosisCite this page: Abdelzaher E. Tanycytic ependymoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cnstumorependymomatanycytic.html. Accessed April 13th, 2021.
Definition / general
- Grade II of IV
- Within brain or spinal cord (often cervical, Acta Neuropathol (Berl) 2001;101:43) parenchyma
- Tanyctes are common progenitor cells of both ependymal cells and astrocytes; are elongated, unipolar or bipolar, extend from ventricular lumen to surface of nervous system
- Important to distinguish from diffuse astrocytomas, which usually cannot be totally excised
Case reports
- 18 year old woman with case associated with neurofibromatosis 2 (Neurol Med Chir (Tokyo) 2001;41:513)
- 30 year old man with case associated with neurofibromatosis 2 (Clin Neuropathol 2001;20:93)
- 39 year old woman with cervical intramedullary tumor (Neurochirurgie 2003;49:605)
- 55 year old woman with intraventricular tumor (J Neurooncol 2005;71:189)
- 58 year old man with spinal tumor associated with hematomyelia (Neurol Med Chir (Tokyo) 2005;45:168)
Treatment
- Gross total excision and radiologic surveillance for recurrence
Microscopic (histologic) description
- Fibrillar variant of ependymoma
- Discrete margin with surrounding tissue
- Features of ependymoma and astrocytoma
- Elongated spindle cells with round / oval nuclei with distinctly light and dark regions of chromatin (similar to ependymoma) and marked fibrillarity (similar to astrocytoma)
- Ependymal rosettes are typically absent and pseudorosettes only vaguely delineated
Microscopic (histologic) images
Contributed by Eman Abdelzaher, M.D., Ph.D.
H&E
EMA showing dot-like and ring-like positivity
Cytology description
- Cells with long, bipolar glial processes and oval nuclei
- May be no pseudorosettes
- Resembles pilocytic astrocytoma or schwannoma (Diagn Cytopathol 2001;24:289)
Electron microscopy description
- Recommended if diagnosis is in doubt; characteristic ependymal features including intracytoplasmic intermediate filaments, prominent intercellular junctions, numerous slender surface microvilli, microvilli lined lumina (Ultrastruct Pathol 1997;21:135)
Differential diagnosis
- Astrocytoma
- Pilocytic astrocytoma
- Schwannoma: reticulin rich
