Distinguishing mature from immature ovarian teratoma in the pre-operative setting

Objective: To identify clinical, sonographic and laboratory findings that might distinguish mature from immature ovarian teratoma in a pre-operative setting. Methods: A retrospective case-control study performed in a tertiary medical center between 1995 and 2023. The study group comprised of 22 women who were surgically diagnosed with immature ovarian teratoma. A control group of 44 women with a mature ovarian teratoma was created, matched two-to-one according to age and year of surgery. Results: Women in the study group were younger (mean 17.7 (8.7) vs 23.2 (7.7), p = 0.01) and more commonly were symptomatic (abdominal pain 95.5 % vs. 61.4 %, p < 0.01; Palpation of mass 54.5 % vs. 29.5 %, p = 0.04). Other symptoms such as pressure symptoms and vomiting were comparable between the groups. Larger tumor size (max diameter, mean (SD) 135 mm (46.9) vs. 95 mm (70.9), p < 0.01), and presence of ascites (31.8 % vs. 2.3 %, p < 0.01) were more common among the study group, whereas abnormal doppler flow, presence of septations and a solid ovarian mass were comparable between the groups. Elevated levels of CA-125 and of AFP were more common among those with immature teratoma compared to mature teratoma (40.9 % vs. 6.8 % P < 0.01; 59.1 % vs. o%, p < 0.01). In a multivariable analysis, Tumor size > 10 cm (OR 10.6, CI [2.7–40.9]) and ascites (OR 12.9 CI [1.1–151.6]) were independent factors associated with immature ovarian teratoma. Conclusion: Tumor size > 10 CM and presence of ascites might aid in the pre-operative differentiation between mature and immature ovarian teratomas, possibly contributing to surgical approach planning.