We recommend that children with a germline pathogenic variant in DICER1, especially those younger than 10 years, undergo annual dilated ophthalmic examination, looking for evidence of CBME, signs of increased ICP, and perhaps changes in the retinal pigment epithelium.
The DICER1 PPB familial tumor predisposition syndrome is initially recognized in most cases on the basis of PPB alone but also by several other unique and characteristic extrapulmonary tumors, including pediatric cystic nephroma, nasal chondromesenchymal hamartoma, nodular lesions of the thyroid, embryonal rhabdomyosarcoma of the cervix, and ciliary body medulloepithelioma.
This case highlights the potential use of DICER1 gene sequencing to resolve the diagnostic challenge in recurrent and metastatic malignant medulloepithelioma, when morphology and immunohistochemistry are inconclusive.