neoplasm (disease) embryonal neoplasm A usually malignant neoplasm composed of primitive (immature) tissues that resemble fetal tissues. Medulloblastoma, Ependymoblastoma, Pineoblastoma, and Wilms tumor are representative embryonal neoplasms. --2003 DOID:688 EFO:0005784 EMBT MONDO:0005564 NCIT:C3264 ONCOTREE:EMBT UMLS:C0027654 embryo neoplasm embryonal cancer embryonal neoplasm embryonal tumor