Meduloepithelioma -CEW

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====== Meduloepithelioma ======
FIXME

====Ciliary Body Meduloepithelioma====
a primitive neuroepithelial neoplasm arising from the nonpigmented ciliary epithelium, typically diagnosed in young children with an average age of six years.[2] Patients may present with decreased visual acuity, leukocoria, or new strabismus. On examination, findings include a visible retrolental ciliary body mass, cataract with subluxation, and possible secondary glaucoma.[2] Although histologically malignant, distant metastasis and mortality are rare; when mortality occurs, it typically results from intracranial spread rather than systemic metastases.[2]

===DICER1 gene mutations===
==Ciliary body medulloepithelioma (CBME)== is the most significant ocular manifestation of DICER1 syndrome, occurring in approximately **3%** of individuals with germline DICER1 mutations. Additionally, **retinal abnormalities** are found in about **11%** of DICER1 carriers, significantly higher than the 1.5% rate in controls.[1][2]

Importantly, in a prospective study of 103 DICER1 carriers, three patients (3%) had CBME, with two identified during routine examination despite having normal dilated eye exams within one year prior to diagnosis.[1] This highlights the importance of regular surveillance. Both germline and somatic DICER1 mutations have been identified in CBME, with somatic mutations frequently occurring in the RNase IIIb domain.[3][4]

==Retinal and Other Ocular Abnormalities==

Beyond CBME, DICER1 carriers show a significantly increased rate of retinal abnormalities (11%) compared to family controls (1.5%).[1][2] These include:

- **Retinal pigment abnormalities** (5.8%)
- **Increased cup-to-disc ratio** (4.9%)
- **Epiretinal membranes** (1.9%)
- **Optic nerve abnormalities** (1.9%)
- **Drusen** (1.9%)
- **[Retinitis pigmentosa](https://www.openevidence.com/rare-disease/retinitis-pigmentosa)** (rare)[1][2]

One patient showed optic nerve elevation in the setting of increased intracranial pressure of unclear cause.[1] Despite these findings, most DICER1 carriers (97%) maintain visual acuity of 20/40 or better in both eyes.[1]

## Surveillance Recommendations

Current recommendations suggest that children with germline pathogenic DICER1 variants, especially those younger than 10 years, should undergo **annual dilated ophthalmic examination** to screen for CBME, signs of increased intracranial pressure, and retinal pigment epithelium changes.[1][2]

Would you like me to explore the surveillance protocols and management strategies for DICER1 syndrome more broadly, including screening for other associated tumors?

==== References ====

1. DICER1 Syndrome: Characterization of the Ocular Phenotype in a Family-Based Cohort Study. Huryn LA, Turriff A, Harney LA, et al. Ophthalmology. 2019;126(2):296-304. doi:10.1016/j.ophtha.2018.09.038.
2. DICER1 Tumor Predisposition. Schultz KAP, Stewart DR, Kamihara J, et al. GeneReviews® [Internet]. Updated 2020 Apr 30.
3. Somatic Mutations of DICER1 and KMT2D Are Frequent in Intraocular Medulloepitheliomas. Sahm F, Jakobiec FA, Meyer J, et al. Genes, Chromosomes & Cancer. 2016;55(5):418-27. doi:10.1002/gcc.22344.
4. Somatic DICER1 Gene Mutation in Sporadic Intraocular Medulloepithelioma Without Pleuropulmonary Blastoma Syndrome. Durieux E, Descotes F, Nguyen AM, Grange JD, Devouassoux-Shisheboran M. Human Pathology. 2015;46(5):783-7. doi:10.1016/j.humpath.2015.01.020.