Clinical and Sonographic Features of Neonatal Ovarian Cysts With Autoamputation

PURPOSE: Autoamputation is a rare but severe complication of neonatal ovarian cysts. This case series describes the clinical, sonographic, and pathological characteristics of neonatal ovarian cysts that progressed to autoamputation, compared with those that did not, based on a retrospective review of 19 cysts. We aim to help clinicians suspect autoamputation when managing complex neonatal ovarian cysts. METHODS: Medical records of 18 neonates (19 ovarian cysts) treated at two medical centers between January 2012 and December 2023 were reviewed. All cysts appeared complex on postnatal ultrasonography. We documented prenatal and postnatal sonographic features (cyst size, solid components, septations, fluid-debris levels, calcification), timing of examinations, intraoperative findings (adhesions, autoamputation), and pathology results. Descriptive statistics and exploratory comparisons between autoamputation (n = 9 cysts) and non-autoamputation (n = 10 cysts) groups were performed, without claims of predictive modeling. RESULTS: Of the 19 complex ovarian cysts, 9 (47.3%) were confirmed autoamputated at surgery. The autoamputation group showed a longer median interval from first complex features to surgery (68 vs. 21.5 days) and an older age at last postnatal ultrasound (11 vs. 1 days). Intra-abdominal adhesions were observed in 66.7% of autoamputation cases versus 10% of non-autoamputation cases. Follicles were absent in all autoamputated cysts on pathology but present in 90% of non-autoamputated cysts. Sonographic findings evolved over time: fluid-debris levels became the predominant feature with increasing duration, while calcification appeared late (22.2% in the autoamputation group). CONCLUSION: Autoamputation of neonatal ovarian cysts was associated with a longer interval from first complex features to surgery, absence of follicles on pathology, and frequent intra-abdominal adhesions. Sonographic features evolved over time, with fluid-debris levels becoming common and calcification appearing late but with poor sonographic sensitivity. These observations may help clinicians better understand the evolution of complex neonatal ovarian cysts associated with autoamputation; however, the diagnostic and predictive value of these findings requires further validation.