Giant ovarian cyst mimicking no-weight loss after sleeve gastrectomy.

Giant ovarian cysts (GOC) are rare due to early ultrasound detection but may reach large dimensions, causing complications. Most are benign mucinous cystadenomas, though borderline or malignant forms exist. A 20-year-old woman, previously submitted to sleeve gastrectomy, presented with acute abdominal pain. Imaging showed a cystic mass measuring 32 × 27 cm, compressing bowel loops and the inferior vena cava. A midline laparotomy was performed with complete excision of the intact mass. Histology confirmed benign mucinous cystadenoma of the left ovary. Recovery was uneventful, and the patient was discharged on Day 3. This case emphasizes the challenges of GOC management in young women and the potential risks of diagnostic delay due to obesity condition. While laparoscopy may be feasible in selected cases, laparotomy is preferred for very large lesions. Fertility preservation, multidisciplinary planning, and surgical strategy are essential. Personalized management allows safe outcomes and fertility preservation in GOC.