To build on this, the majority ofpatients with germline DICER1 syndrome have been shown to harboradditional somatic DICER1 mutations in hyperplasic areas within aTFND (40), suggestive of clonal events.DICER1-associated TFND may show prominent papillary infoldingand multiple hyperplastic nodules, which could potentially be a morphological cluetriaging patients for DICER1 genetic screening (37) (Fig.4). Here, DICER1 is linked to Down syndrome.