# Presumed Bilateral Ciliary Body Medulloepithelioma in a Child with Pleuropulmonary Blastoma and DICER1 Mutation

## TL;DR

A child with a rare cancer syndrome developed a rare eye tumor in both eyes, highlighting the need for regular eye exams in similar cases.

## Contribution

This case is the first reported instance of presumed bilateral ciliary body medulloepithelioma in a patient with DICER1 syndrome.

## Key findings

- The patient had a history of pleuropulmonary blastoma and a DICER1 mutation.
- Bilateral ciliary body medulloepithelioma was diagnosed and successfully treated with globe-sparing therapy.
- Regular ophthalmological screening is crucial for early detection in patients with DICER1 syndrome.

## Abstract

Background and clinical significance: Ciliary body medulloepithelioma (CBME) is a rare germinal tumor deriving from nonpigmented ciliary epithelium, usually occurring during the first decade of life. Typically, the diagnosis is delayed as a result of the tumor’s slow growth and late onset of symptoms. Primary enucleation is commonly required; nevertheless, globe-sparing means of therapy have been successful in selected cases. CBME is among the spectrum of neoplasms associated with DICER1 cancer predisposition syndrome. Case presentation: Herein, we report a case of a 6-year-old boy with a history of pleuropulmonary blastoma type II and DICER1 mutation who presented with leukocoria in his right eye. After a thorough ophthalmological evaluation, he was diagnosed with CBME. Because of the large size of the lesion and vitreous seeding, the eye was enucleated. Histopathology confirmed the diagnosis of a benign teratoid medulloepithelioma. After 2 years of regular ophthalmological examinations, a new lesion was detected in the left eye. Three cycles of transscleral cryotherapy allowed for tumor control and globe salvage. The patient remains recurrence-free 6 months after the last treatment. Conclusions: This report should raise awareness among clinicians about the possibility of bilateral CBME and the necessity of regular ophthalmological screening in patients with DICER1 syndrome, especially those previously treated for CBME.