Ciliary body medulloepithelioma: four cases associated with pleuropulmonary blastoma--a report from the International Pleuropulmonary Blastoma Registry.

BACKGROUND AND AIMS: Ciliary body medulloepithelioma (CBME) is a rare embryonal ocular tumour of children under age 10 years. Pleuropulmonary blastoma (PPB) is a rare embryonal lung tumour in young children and the sentinel disease of the PPB Family Tumour and Dysplasia Syndrome, a distinctive predisposition leading to unusual dysontogenetic-dysplastic and neoplastic conditions in PPB patients and their relatives. Germline mutations of DICER1 gene, a key regulator of gene silencing, underlie this syndrome. CBME occurs with PPB. The authors' aim was to identify CBME cases associated with PPB.
METHODS: The authors evaluated International PPB Registry and literature PPB cases for CBME, including review of pathologic specimens.
RESULTS: Four CBME were observed among 550-600 PPB cases; three in patients and one in a parent. One CBME was clinically diagnosed; three were confirmed pathologically (one benign teratoid CBME; one benign non-teratoid CBME; one case, details not available).
CONCLUSIONS: These observations suggest that CBME is a manifestation of the tumour predisposition associated with PPB. Paediatric oncologists and ophthalmologists should be aware that CBME can occur in PPB patients or their relatives and that CBME may indicate a hereditable tumour predisposition for a child or family.