DICER1 and pleuropulmonary blastoma: DICER1 syndrome, also known as pleuropulmonary blastoma familial tumor and dysplasia syndrome, is a rare autosomal dominant disorder (estimated prevalence of 1:10,600) caused by a mutation in the DICER1 gene on chromosome 14q leading to downstream alteration of an RNase III endoribonuclease.1, 2, 3 Patients with this genetic mutation are at an increased risk for a range of tumors, particularly pleuropulmonary blastomas.2