TY - BOOK AU - Popen-Rono, Onelth Dec A. AU - Castro, Abigail Elsie DG., AU - Duenas, Rommel Z. TI - One big transition: three cases of malignant transformation of mature cystic teratoma / : [author]: Popen-Rono, Onelth Dec A. [co-authors]: Castro, Abigail Elsie DG., Duenas, Rommel Z. AV - OB 2024 0001 PY - 2024/// CY - Fairview, Quezon City PB - Department of Obstetrics & Gynecology, FEU-NRMF N1 - Includes bibliographical references; RESDOG N2 - ABSTRACT: Mature Cystic Teratoma accounts for more than 90% of a benign ovarian germ cell tumor of the ovary. One of its rare complication is malignant transformation, which occurs in about 1-3% of cases. Three cases of premenopausal women were diagnosed as such postoperatively. One had squamous cell carcinoma histology who presented with abdominal mass and two cases of papillary thyroid carcinoma were asymptomatic. Preoperative tumor markers and diagnostic imaging were done. All cases underwent surgery either open laparotomy or laparoscopy. Intraoperatively, gross tumors were unilateral with sizes ranging from 3.5-14 cm in greatest diameter. Final histopathology confirmed the diagnosis of malignant transformation arising from a mature cystic teratoma. Post-operative management and prognosis were discussed. Keywords: mature cystic teratoma, dermoid cyst, malignant transformation, squamous cell carcinoma, papillary thyroid carcinoma ER -