Frequency of adenoma-to-carcinoma-sequence in borderline ovarian tumors (BOT): A systematic analysis of BOT with different histologic subtypes

Background: Low-grade ovarian carcinomas (Type I tumors), are postulated to develop via a stepwise progression from a benign cystadenoma via borderline ovarian tumors (BOT) into invasive lesion (adenoma to carcinoma sequence). Methods: To evaluate the frequency of adenoma to carcinoma sequence we re-valuated in 74 consecutive cases of BOT with different histologic subtypes. Results: The majority of cases represented serous-BOT (59.5%), followed by mucinous BOT (25.7%), other histologic types were rare. 86.5% showed an adenoma-carcinoma sequence, which was seen in all mucinous BOT but was missed in 15.9% of serou…