Basically, this question is the question of “what test should I take for the final diagnosis of dermoid cyst”.
Final diagnosis is made by means of “Contrast-Enhanced (with medicine) Fat-Suppressed Lower Abdominal MRI”. If the cyst is large, an upper abdominal MRI should also be added to this.
Besides this, if the cyst is larger than 10 cm, CA 19.9 and SCC Ag can be considered. There is a limited number of place for SCC-Ag, and it is a relatively expensive technique. It should be performed if CA 19.9 is not much indicative and high, and if the cyst is large.