DICER1 Syndrome and Cancer Predisposition: From a Rare Pediatric Tumor to Lifetime Risk.

DICER1 syndrome is a rare genetic condition predisposing to hereditary cancer and caused by variants in the DICER1 gene. The risk to present a neoplasm before the age of 10 years is 5.3 and 31.5% before the age of 60. DICER1 variants have been associated with a syndrome involving familial pleuropulmonary blastoma (PPB), a rare malignant tumor of the lung, which occurs primarily in children under the age of 6 years and represents the most common life-threatening manifestation of DICER1 syndrome. Type I, II, III, and Ir (type I regressed) PPB are reported with a 5-year overall survival ranging from 53 to 100% (for type Ir). DICER1 gene should be screened in all patients with PPB and considered in other tumors mainly in thyroid neoplasms (multinodular goiter, thyroid cancer, adenomas), ovarian tumors (Sertoli-Leydig cell tumor, sarcoma, and gynandroblastoma), and cystic nephroma. A prompt identification of this syndrome is necessary to plan a correct follow-up and screening during lifetime.