Giant Ovarian Cystadenoma Mimicking Massive Ascites: A Case Report

Giant ovarian cysts may present with nonspecific abdominal symptoms and can clinically and sonographically mimic massive ascites. This diagnostic overlap may lead to extensive workup for hepatic, cardiac, infectious, vascular, or malignant causes before the underlying gynecological pathology is recognized. We report the case of a 24-year-old woman who presented with progressive abdominal distension, flatulence, and nonspecific abdominal discomfort. The initial ultrasound was interpreted as massive ascites, and 12 liters of presumed ascitic fluid were drained. Fluid analysis showed a very low cell count and no evidence of malignancy or infection. Further investigations, including blood tests, computed tomography (CT), and transjugular liver biopsy, did not reveal an underlying cause. During follow-up, recurrent intra-abdominal fluid was noted, later appearing loculated rather than freely distributed. After interdisciplinary discussion, diagnostic laparoscopy was performed and revealed a giant ovarian cyst measuring up to 18 cm in maximum diameter and containing approximately 2 liters of residual fluid. The patient underwent left-sided oophorectomy and histopathology showed a benign serous cystadenoma. The postoperative course was uneventful, and the patient remained symptom-free during follow-up. This case highlights that giant ovarian cysts may be misinterpreted as ascites. In patients with presumed ascites of unclear origin and repeatedly negative diagnostic findings, cystic gynecological lesions should be considered. Diagnostic laparoscopy may be decisive when noninvasive investigations fail to establish the diagnosis and can allow simultaneous therapeutic intervention.