Gynecologic carcinomas with RAS mutations may show a wide spectrum of histologic types, including mixed types. We present the case of a 63-yr-old patient diagnosed with an ovarian tumor harboring a mesonephric-like adenocarcinoma in a background of mixed mesonephric-like, mucinous, and endometrioid components. Molecular analysis revealed that all 3 components shared the same clonal KRAS mutation (p.G12A) and chromosome 1q gain. Based on shifts in clonality, copy number gains, and acquisition of an additional mutation, our data suggest that the mucinous component likely constituted the substrate from which the mesonephric-like and endometrioid components arose.

We describe a very unusual cervical tumor in a 12-yr-old patient with a clinical history indicative of DICER1 syndrome. Morphologic, immunohistochemical, and molecular genetic analysis together helped to diagnose this lesion as a cervical pleuropulmonary blastoma-like tumor, associated with TP53 and DICER1 mutations. The tumor displayed usual histologic features including mixtures of embryonal rhabdomyosarcoma, sarcomatous cartilage, compact blastema, primitive spindle cells and anaplasia, akin to type III pleuropulmonary blastoma, and trabecular and retiform patterns. In addition to expanding the phenotypic spectrum of DICER1-associated conditions, we draw attention to genotype-phenotype correlations in DICER1-associated tumors, particularly as they relate to the discovery of a heritable tumor predisposition syndrome.