Medulloepithelioma
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]
| Medulloepithelioma | |
|---|---|
| Histopathology of medulloepithelioma showing characteristic neural tube like strands. | |
| Specialty | Neurosurgery, Neuro-oncology |
A highly malignant undifferentiated primitive neuroepithelial tumour of children, medulloepithelioma may contain bone, cartilage, skeletal muscle, and tends to metastasize extracranially.[2]
Signs and symptoms edit
Medulloepithelioma have been reported to occur in the cerebral hemispheres, brainstem, cerebellum, and peripheral sites.[3][4][5][6]
Due to rapid growth of the tumour, patients typically present with increased intracranial pressure, seizures, and focal neurologic signs.[7]
Diagnosis edit
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.[3] This radiographical finding is consistent with a primitive neuroectodermal tumour, especially in children.[6] Blood studies and imaging studies of the abdomen may be used to detect metastases.[6]
Needle aspiration biopsy can be used to aid diagnosis.[6] Definitive diagnosis requires histopathological examination of surgically excised tumour tissues.[citation needed]
Histologically, medulloepithelioma resemble a primitive neural tube and with neuronal, glial and mesenchymal elements.[8][9] Flexner-Wintersteiner rosettes may also be observed.[10]
Immunohistochemically, neural tube-like structures are vimentin positive in the majority of medulloepitheliomas.[11] Poorly differentiated medulloepitheliomas are vimentin negative.[citation needed]
Classification edit
Medulloepithelioma was originally classified as the most primitive neoplasm of the Central Nervous System (CNS) by Bailey and Cushing in 1926.[4] Rorke et al.[12] 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.
Treatment edit
Total resection of the tumour, followed by radiation therapy is the standard treatment modality.[3] Medulloepithelioma of the ciliary body may necessitate enucleation of the eye.[13][14] Radiation therapy alone may prolong survival.[3] Aggressive chemotherapy with autologous bone marrow transplant is used for metastatic medulloepitheliomas.[6]
Prognosis edit
Medulloepithelioma carries a dismal prognosis with a median survival of 5 months.[3][15][16][17]
Epidemiology edit
Medulloepithelioma most commonly affect children between 6 months and 5 years; rarely, this tumour may occur congenitally or beyond this age range.[8][18][19] Incidence is equal in males and females.[3]
References edit
- ^ a b Definition of Medulloepithelioma 2015-12-25 at the Wayback Machine, from Online Medical Dictionary. Retrieved 7 January 2010.
- ^ a b McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
- ^ a b c d e f 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.
- ^ a b 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.
- ^ Karch SB, Urich H. Medulloepithelioma: definition of an entity. J Neuropathol Exp Neurol 1972;31:27-53.
- ^ a b c d e 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.
- ^ a b Russel DS, Rubinstein LJ. Pathology of tumors the nervous system, 5th ed. Baltimore: Williams & Wilkins 1989; pp. 247-51.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.