An adenocarcinoma that arises from the ovary and is characterized by the presence of cystic structures. It includes the serous cystadenocarcinoma, mucinous cystadenocarcinoma, and clear cell cystadenocarcinoma. The disease is Monarch Disease Ontology id MONDO_0002702 (ovarian cystadenocarcinoma). Also known as: cystadenocarcinoma of ovary, cystadenocarcinoma of the ovary, ovary cystadenocarcinoma.