Medulloepithelioma
| Medulloepithelioma | |
| Classification and external resources | |
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| Histopathology of medulloepithelioma showing characteristic neural tube like strands. |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Medulloepithelioma is a rare, primitive, fast-growing brain tumour thought to stem from cells of the embryonic medullary cavity.[1] Tumours originating in the ciliary body of the eye are referred to as embryonal medulloepitheliomas,[1] or diktyomas.[2]
A highly malignant undifferentiated primitive neuroepithelial tumour of children, medulloepithelioma may contain bone, cartilage, skeletal muscle, and tends to metastasize extracranially.[2]
Epidemiology
Medulloepithelioma most commonly affect children between 6 months and 5 years; rarely, this tumour may occur congenitally or beyond this age range.[3][4][5] Incidence is equal in males and females.[6]
Classification
Medulloepithelioma was originally classified as the most primitive neoplasm of the Central Nervous System (CNS) by Bailey and Cushing in 1926.[7] Rorke et al.[8] classified this tumour into two subtypes:
- 1) medulloepithelioma not otherwise specified
- 2) medulloepithelioma with differentiation into astrocytes, oligodendrocytes; ependymal cells; neuronal cells; others (melanin, mesenchymal cells); and mixed cellular elements.
Clinical manifestation
Medulloepithelioma have been reported to occur in the cerebral hemispheres, brainstem, cerebellum, and peripheral sites.[6][7][9][10]
Due to rapid growth of the tumour, patients typically present with increased intracranial pressure, seizures, and focal neurologic signs.[11]
Diagnosis
Imaging studies such as Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI) can aid diagnosis. Medulloepithelioma appears isodense or hypodense with variable heterogeneity and calcification on non-contrast CT scan, and enhances with contrast.[6] This radiographical finding is consistent with a primitive neuroectodermal tumour, especially in children.[10] Blood studies and imaging studies of the abdomen may be used to detect metastases.[10]
Needle aspiration biopsy can be used to aid diagnosis.[10] Definitive diagnosis requires histopathological examination of surgically excised tumour tissues.
Histologically, medulloepithelioma resemble a primitive neural tube and with neuronal, glial and mesenchymal elements.[3][12] Flexner-Wintersteiner rosettes may also be observed.[13]
Immunohistochemically, neural tube-like structures are vimentin positive in the majority of medulloepitheliomas.[14] Poorly differentiated medulloepitheliomas are vimentin negative.
Treatment
Total resection of the tumour, followed by radiation therapy is the standard treatment modality.[6] Medulloepithelioma of the ciliary body may necessitate enucleation of the eye.[15][16] Radiation therapy alone may prolong survival.[6] Aggressive chemotherapy with autologous bone marrow transplant is used for metastatic medulloepitheliomas.[10]
Prognosis
Medulloepithelioma carries a dismal prognosis with a median survival of 5 months.[6][17][18][19]
References
- ↑ 1.0 1.1 Definition of Medulloepithelioma, from Online Medical Dictionary. Retrieved 7 January 2010.
- ↑ 2.0 2.1 McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
- ↑ 3.0 3.1 Russel DS, Rubinstein LJ. Pathology of tumors the nervous system, 5th ed. Baltimore: Williams & Wilkins 1989; pp. 247-51.
- ↑ Sato T, Shimoda A, Takahishi T, et al. Congenital cerebellar neuroepithelial tumor with multiple divergent differentiation. Acta Neuropathol 1980;50:143-6.
- ↑ Scheithauer BW, Rubinstein LJ. Cerebral medulloepithelioma: Report of a case with multiple divergent neuroepithelial differentiation. Childs Brain 1979;5:62-71.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 Molly PT, Yachnis AT, Rorke LB, et al. Central nervous system medulloepithelioma a series of eight cases including two arising in the pons. J Neurosurg 1996;84:430-6.
- ↑ 7.0 7.1 Bailey P, Cushing H. A classification of tumors of the glioma group on a histogenetic basis with a correlated study of progress. Philadelphia: JB Lippincott; 1926. pp. 54-6.
- ↑ Rorke LB, Gilles FH, Davis RI, Becker LE. Revision of the World Health Organization classification of brain tumors for child hood brain tumors. Cancer 1985;56:1869-86.
- ↑ Karch SB, Urich H. Medulloepithelioma: definition of an entity. J Neuropathol Exp Neurol 1972;31:27-53.
- ↑ 10.0 10.1 10.2 10.3 10.4 Sundaram C, Vydehi BV, Reddy JJ, Reddy AK. Medulloepithelioma: A case report. Neurol India 2003;51:546-7.
- ↑ Uncommon brain tumors, from UpToDate Online 17.3. Last updated 21 July 2009, Retrieved 7 January 2010.
- ↑ Deck JHN. Cerebral medulloepithelioma with maturation into ependymal cells and ganglion cells. J Neuropathol Exp Neurol 1969;28:442-54.
- ↑ McLean IW, Burnier MN, Zimmerman LE, et al. Tumors of the retina. In: Atlas of tumor pathology: tumors of the eye and ocular adnexa. Washington, DC: Armed Forces Institute of Pathology; 1994:97–154.
- ↑ Troost D, Jansen GH, Dingemans KP. Cerebral medulloepithelioma - electron microscopy and immunohistochemistry. Acta Neuropathol 1990;80:103-7.
- ↑ al-Torbak A, Abboud EB, al-Sharif A, el-Okda MO. Medulloepithelioma of the ciliary body. Indian J Ophthalmol. 2002 Jun;50(2):138-40.
- ↑ Vajaranant, TS, Mafee, MF, Kapur, R, et al. Medulloepithelioma of the ciliary body and optic nerve: clinicopathologic, CT, and MR imaging features. Neuroimaging Clin N Am 2005; 15:69.
- ↑ Sharma MC; Mahapatra AK; Gaikwad S; Jain AK; Sarkar C. Pigmented medulloepithelioma: report of a case and review of the literature. Childs Nerv Syst. 1998 Jan-Feb;14(1-2):74-8.
- ↑ Chidambaram B; Santosh V; Balasubramaniam V. Medulloepithelioma of the optic nerve with intradural extension--report of two cases and a review of the literature. Childs Nerv Syst. 2000 Jun;16(6):329-33.
- ↑ Depper, MH, Hart, BL. Pediatric Brain Tumors. In: Neuroimaging, Orrison, WW (ed), WB Saunders, Philadelphia, 2000. p. 1625.