Ovarian cystadenomas in adolescents are rare neoplastic tumors arising from the ovarian epithelium. These are seen in adult women, posing diagnostic challenges in the pediatric age group. Due to its propensity to become large up to 30cm, its acute presentation and complications necessitate urgent management. We present a case of a 17-year-old female who came in due to increasing abdominal girth of 1-year duration with a CT scan finding of 35 cm hypodense non-enhancing abdominopelvic mass. Tumor markers were requested, leading to non-malignancy, and the patient underwent minimally invasive surgery. This clinical case highlights the importance of a comprehensive approach to the diagnosis of intraabdominal masses in adolescents while providing optimal management and reducing potential complications.