rhabdoid tumor (Monarch Disease Ontology entry MONDO_0002728) is an aggressive malignant embryonal neoplasm usually occurring during childhood. It is characterized by the presence of large cells with abundant cytoplasm, large eccentric nucleus, and a prominent nucleolus and it is associated with abnormalities of chromosome 22. It can arise from the central nervous system, kidney, and the soft tissues. The prognosis is poor. Also known as: malignant rhabdoid tumor, malignant rhabdoid tumour, rhabdoid sarcoma.