A malignant glandular epithelial neoplasm characterized by the presence of clear and hobnail cells. It is highly associated with ovarian endometriosis, pelvic endometriosis and paraendocrine hypercalcemia. The disease is ovarian clear cell adenocarcinoma (MONDO_0006045). Also known as: clear cell adenocarcinoma of ovary, ovary clear cell adenocarcinoma.