An infant with cystic nephroma and a thyroid nodule associated with a pathogenic DICER1 germline variant

Abstract

Individuals with pathogenic DICER1 germline variants are predisposed to developing tumors in various organs, including pleuropulmonary blastoma, as part of DICER1 syndrome. A 6-month-old girl was referred to our hospital with an abdominal mass and feeding difficulties. Physical examination revealed a firm mass on the left side of the abdomen. Imaging demonstrated a multifocal, septated tumor in the left kidney. The patient underwent a total left nephrectomy, and histopathological analysis confirmed the diagnosis of cystic nephroma. Additionally, imaging at the time of diagnosis detected a nodule in the left lobe of the thyroid gland. Genetic testing identified a pathogenic DICER1 germline variant, confirming the diagnosis of DICER1 syndrome. No additional DICER1-associated tumors were detected during the 3 years of postoperative follow-up. It is noteworthy that thyroid tumors in individuals with DICER1 syndrome typically manifest after the age of 10, making the concurrent presence of a cystic nephroma and a thyroid nodule in infancy an uncommon finding. Close monitoring is essential to assess thyroid nodule growth and the potential development of new tumors.