Medulloepithelioma: Difference between revisions
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*[[Optic nerve]] injury | *[[Optic nerve]] injury | ||
*Increased [[intracranial pressure]] | *Increased [[intracranial pressure]] | ||
*CNS dissemination<ref name="pmid8609554">{{cite journal| author=Molloy PT, Yachnis AT, Rorke LB, Dattilo JJ, Needle MN, Millar WS et al.| title=Central nervous system medulloepithelioma: a series of eight cases including two arising in the pons. | journal=J Neurosurg | year= 1996 | volume= 84 | issue= 3 | pages= 430-6 | pmid=8609554 | doi=10.3171/jns.1996.84.3.0430 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8609554 }}</ref> | |||
===Prognosis=== | ===Prognosis=== | ||
The prognosis of medulloepithelioma is generally poor; the median survival time of patients with medulloepithelioma is approximately 5 months. | The prognosis of medulloepithelioma is generally poor; the median survival time of patients with medulloepithelioma is approximately 5 - 10 months.<ref name="pmid8609554" /> | ||
== Diagnosis == | == Diagnosis == | ||
Revision as of 13:52, 2 May 2019
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Maria Fernanda Villarreal, M.D. [2] Roukoz A. Karam, M.D.[3]
Synonyms and keywords: Medullary epithelioma, Diktyoma
Overview
Medulloepithelioma is a rare, primitive, fast-growing brain tumor thought to stem from cells of the embryonic medullary cavity. Tumors originating in the ciliary body of the eye are referred to as embryonal medulloepitheliomas or diktyomas. Medulloepithelioma was first discovered by Bailey and Cushing in 1926. The pathogenesis of medulloepithelioma is characterized by highly malignant undifferentiated primitive neuroepithelial tumor. Tumors generally originate in the ciliary body of the eye. It most commonly manifests in the cerebral hemispheres, brainstem, cerebellum, and in peripheral sites. Medulloepithelioma arises from primitive medullary epithelium, which is normally involved in the embryonic formation of CNS. Medulloepithelioma commonly affects individuals younger than 4-5 years of age. On CT, findings of medulloepithelioma, include an isodense or hypodense lesion with variable heterogeneity and calcification. Surgery is the mainstay of therapy for medulloepithelioma. Total resection in conjunction with radiation therapy is the most common approach to the treatment of medulloepithelioma.
Historical Perspective
Medulloepithelioma was first discovered by Bailey and Cushing in 1926.
Classification
Medulloepitheliomas are classified as embryonal tumors in the WHO classification of CNS tumors.[1]
In 2016, the WHO classification system was reviewed and identified the tumors that were previously labeled embryonal tumor with abundant neuropil and true rosettes, ependymoblastoma, and medulloepithelioma and included them in embryonal tumor with multilayered rosettes (ETMR) group; provided they have evidence of C19MC amplification.[2]
- ETMR are highly malignant pediatric tumors with varied embryonal histology but shared genetic alterations in the C19MC gene.
Medulloepithelioma may be classified into 3 groups:
- Medulloepithelioma not otherwise specified
- Medulloepithelioma with differentiation into astrocytes, oligodendrocytes; ependymal cells
- Medulloepithelioma with neuronal cells, other cells (melanocytes, mesenchymal cells), and mixed cellular elements
Pathophysiology
Pathogenesis
The pathogenesis of medulloepithelioma is characterized by:
- A highly malignant undifferentiated primitive neuroepithelial tumor
- Tumors generally originate in the ciliary body of the eye
- Located in cerebral hemispheres, brainstem, cerebellum, and peripheral sites
Medulloepithelioma arises from primitive medullary epithelium, which is normally involved in the embryonic formation of CNS.
Genetics
The germline DICER1 gene mutation has been associated with the development of medulloepithelioma.
Gross Pathology
This tumor most commonly appears as a white, gray, or yellow-colored ciliary body tumor.[3]
Microscopic Pathology
On microscopic histopathological analysis, characteristic findings of medulloepithelioma may include:
- Small round blue cell tumor
- Focal differentiation into astrocytic, neuronal or ependymal phenotypes possible
- Multilayered rosettes may be seen
- Growth in streams or palisades
- Vascular endothelial proliferations
- Fibrillary background in tumors with advanced neuronal maturation
- Variable mitotic activity
- Neoplastic pseudostratified neuroepithelium
- Resembling embryonic neural tube, with papillary, tubular and trabecular arrangements
- Sheets of poorly differentiated cells
- With hyperchromatic nuclei and high N/C ratio
- Periodic acid-Schiff positive external limiting membrane
- No cilia or blepharoplasts on luminal surface of tubules
On immunohistopathological analysis, characteristic findings of medulloepithelioma may include:
- Positive S-100
- Positive INI1
- Positive LIN28
Causes
The cause of medulloepithelioma is unknown.
Differentiating Medulloepithelioma from Other Diseases
Medulloepithelioma must be differentiated from other diseases that cause vision loss, ocular mass, and headache such as:
- CNS tumors
- Retinoblastoma
- Shares radiologic features with medulloepithelioma
- Intraocular lymphoma
- Anterior chamber cyst
Epidemiology and Demographics
Medulloepithelioma is a rare disease.
Age
Medulloepithelioma commonly affects individuals younger than 4-5 years of age.[4]
The median age at diagnosis is 5 years old.[5]
Gender
Medulloepithelioma affects men and women equally.
Race
There is no racial predilection for medulloepithelioma.
Risk Factors
There are no known associated risk factors in the development of medulloepithelioma.
Screening
There is insufficient evidence to recommend routine screening for medulloepithelioma.
Natural History, Complications and Prognosis
Natural History
- Patients with medulloepithelioma may be initially asymptomatic.
- Early clinical features include vision loss, irritability, and neurological deficit. If left untreated, patients with medulloepithelioma may progress to death.[5]
- Medulloepithelioma have been reported to occur in the cerebral hemispheres, brainstem, cerebellum, and peripheral sites.
Complications
Common complications of medulloepithelioma include:[5]
- Optic nerve injury
- Increased intracranial pressure
- CNS dissemination[6]
Prognosis
The prognosis of medulloepithelioma is generally poor; the median survival time of patients with medulloepithelioma is approximately 5 - 10 months.[6]
Diagnosis
Diagnostic Study of Choice
The diagnosis of medulloepithelioma is based on immunhistochemistry, which reveals an over-expression of LIN28A protein.[7]
Previously, the diagnosis of medulloepithelioma required only morphological analysis; however, the World Health Organization classification of central nervous system tumors was revised, and now genetic analysis is necessary.[7]
History & Symptoms
Medulloepithelioma is usually asymptomatic; however, signs and symptoms of increased intracranial pressure may be sign upon presentation.[5]
Symptoms of medulloepithelioma may include:[5]
Physical Examination
Patients with medulloepithelioma usually are well-appearing. Physical examination may be remarkable for:
- Paralysis of a limb (monoparesis) or hemiparesis
- Paralysis of the head and eye movements
- Total loss of vision
Laboratory Findings
There are no specific laboratory findings associated with medulloepithelioma.
Imaging Findings
CT and MR imaging findings can be helpful, especially if the mass is confined in an area of the ciliary body without involvement of the retina.[8]
X-ray Findings
There are no x-ray findings associated with medulloepithelioma.
CT Findings
Brain CT scan may be helpful in the diagnosis of medulloepithelioma.
Findings on CT scan suggestive of medulloepithelioma include isodense or hypodense lesions with variable heterogeneity and calcification.
The tumor enhances with contrast.
MRI Findings
MRI may be helpful in the diagnosis of medulloepithelioma. Findings on MRI suggestive of medulloepithelioma
Treatment
Medical Therapy
There is no standard regimen for medulloepithelioma due to its rarity, although craniospinal radiation, high dose chemotherapy with stem cell rescue has been used.
Surgery
Complete surgical resection is the mainstay of treatment for medulloepithelioma.
Adjuvant radiochemotherapy is often indicated.[9]
Prevention
There are no primary preventive measures available for medulloepithelioma.
References
- ↑ Louis DN, Perry A, Reifenberger G, von Deimling A, Figarella-Branger D, Cavenee WK; et al. (2016). "The 2016 World Health Organization Classification of Tumors of the Central Nervous System: a summary". Acta Neuropathol. 131 (6): 803–20. doi:10.1007/s00401-016-1545-1. PMID 27157931.
- ↑ Korshunov A, Sturm D, Ryzhova M, Hovestadt V, Gessi M, Jones DT; et al. (2014). "Embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma, and medulloepithelioma share molecular similarity and comprise a single clinicopathological entity". Acta Neuropathol. 128 (2): 279–89. doi:10.1007/s00401-013-1228-0. PMC 4102829. PMID 24337497.
- ↑ Broughton WL, Zimmerman LE (1978). "A clinicopathologic study of 56 cases of intraocular medulloepitheliomas". Am J Ophthalmol. 85 (3): 407–18. PMID 655220.
- ↑ Russel DS, Rubinstein LJ. Pathology of tumors the nervous system, 5th ed. Baltimore: Williams & Wilkins 1989; pp. 247-51.
- ↑ 5.0 5.1 5.2 5.3 5.4 Peshtani A, Kaliki S, Eagle RC, Shields CL (2014). "Medulloepithelioma: A triad of clinical features". Oman J Ophthalmol. 7 (2): 93–5. doi:10.4103/0974-620X.137171. PMC 4134557. PMID 25136238.
- ↑ 6.0 6.1 Molloy PT, Yachnis AT, Rorke LB, Dattilo JJ, Needle MN, Millar WS; et al. (1996). "Central nervous system medulloepithelioma: a series of eight cases including two arising in the pons". J Neurosurg. 84 (3): 430–6. doi:10.3171/jns.1996.84.3.0430. PMID 8609554.
- ↑ 7.0 7.1 Kusakabe K, Kohno S, Inoue A, Seno T, Yonezawa S, Moritani K; et al. (2018). "Combined morphological, immunohistochemical and genetic analyses of medulloepithelioma in the posterior cranial fossa". Neuropathology. 38 (2): 179–184. doi:10.1111/neup.12431. PMID 28971535.
- ↑ Vajaranant TS, Mafee MF, Kapur R, Rapoport M, Edward DP (2005). "Medulloepithelioma of the ciliary body and optic nerve: clinicopathologic, CT, and MR imaging features". Neuroimaging Clin N Am. 15 (1): 69–83. doi:10.1016/j.nic.2005.02.008. PMID 15927861.
- ↑ Oumghar, Nezha; Hazmiri, Fatima Ezzahra; El Omrani, Abdelhamid; Rais, Hanane; Khouchani, Mouna (2017). "Posterior cerebral fossa medulloepithelioma: report of a case". BMC Clinical Pathology. 17 (1). doi:10.1186/s12907-017-0064-x. ISSN 1472-6890.