Pediatric puzzle: Large ovarian dermoid cyst and markedly elevated CA 19-9 in an 8-year-old

This case highlights the occurrence of a large mature cystic teratoma with elevated CA-19-9 in a pediatric patient with no complications such as torsion, rupture, or malignancy. The elevation in CA-19-9 likely relates directly to the teratoma itself. A conservative, fertility-sparing surgical approach proved effective, emphasizing the importance of careful preoperative evaluation and management in similar cases.