AIM: To investigate whether ovarian cancer in children and young adults, display the same accepted sonographic features that raise suspicious of ovarian malignancy among adults, and whether sonographic features predict clinical behavior. METHODS: A matched case-control study. The study group comprised all youngsters <
25 years of age diagnosed with ovarian cancer in a tertiary university hospital between the years 1995-2023. A control group with benign ovarian masses was matched according to age and year of diagnosis in a 2:1 ratio. Clinical data, sonographic features and disease outcomes were compared. RESULTS: The study group included 30 youngsters, 24 (80 %) of them had germ cell tumors, 4 (13.3 %) sex-cord tumors and two (6.7 %) were epithelial tumors. The control group included 60 youngsters, of them 27 (45 %) with mature teratomas, 25 (41.6 %) serous cystadenomas and 8 (13.4 %) with other benign ovarian tumors. In a univariate analysis, Palpation of mass (43.3 % vs. 15 %, p <
0.01), vomiting (33.3 % vs. 13.3 %, p = 0.02) and elevated tumor markers (79.3 % vs.21.6 %, p <
0.01) were more common in the study group. Malignant masses were larger (mean of maximal diameter 159 mm vs. 88 mm, p <
0.01), were more likely to contain a solid component (60 % vs. 21.7 %, P <
0.01), to have ascites (33.3 % vs. 3.3 %, P <
0.01) and to have a high color content on Doppler examination (50 % vs. 11.7 %, p <
0.01). These features remained significant also in a multivariable analysis. Disease recurrence was not associated with any sonographic parameters. CONCLUSION: sonographic features suspicious for ovarian mass malignancy among adult women are valid also among the young population. However, none of these features are associated with a worse clinical course.