====== Medulloepithelioma ======

=====Ciliary Body Medulloepithelioma=====
  * Primitive neuroepithelial neoplasm arising from the nonpigmented ciliary epithelium
  * Typically diagnosed in young children with an average age of six years
  * Patients may present with decreased visual acuity, leukocoria, or new strabismus. 
  * Findings include a visible retrolental ciliary body mass, cataract with subluxation, and possible secondary glaucoma
  * Histologically malignant but distant metastasis and mortality are rare; when mortality occurs, it typically results from intracranial spread rather than systemic metastases.

====DICER1 gene mutations====
===Ciliary body medulloepithelioma (CBME)===
  * 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.
  * 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
  * Both germline and somatic DICER1 mutations have been identified in CBME, with somatic mutations frequently occurring in the RNase IIIb domain

===Retinal and Other Ocular Abnormalities===

Beyond CBME, DICER1 carriers show a significantly increased rate of retinal abnormalities (11%) compared to family controls (1.5%).
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** (rare)

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

===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

===== References =====

  - [[https://pmc.ncbi.nlm.nih.gov/articles/PMC6348055/|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]]
  - [[https://www.ncbi.nlm.nih.gov/books/NBK196157/|DICER1 Tumor Predisposition. Schultz KAP, Stewart DR, Kamihara J, et al. GeneReviews®. Updated 2020 Apr 30]]
  - [[https://onlinelibrary.wiley.com/doi/10.1002/gcc.22344|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]]
  - [[https://pubmed.ncbi.nlm.nih.gov/25791583/|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]]