Primary Omental Pregnancy: Successful Laparoendoscopic Single-site Partial Omentectomy After Diagnosis by Diffusion-weighted Magnetic Resonance Imaging

A 34-year-old, gravida 2, para 0 woman was referred after 8 weeks of amenorrhea. Serum b-human chorionic gonadotropin value was 828 mIU/mL. Diffusion-weighted magnetic resonance imaging (MRI) [1] showed a hematoma-like mass with heterogeneous signal intensities, adjacent to the omental fat, in the retrovesical space, along with corpus lutein cyst of left ovary (Fig. 1, A and B). Emergency laparoendoscopic single-site (LESS) [1] partial omentectomy was performed because of difficult dissection of the firmly attached gestational mass from the omental tissue (Fig. 1C). Histopathologic examination of the excised specimen confirmed primary omental pregnancy by showing the chorionic villi with direct invasion of trophoblast to the omental fat tissue (Fig. 1D). Primary omental pregnancy, in which the fertilized ovum directly implants into the omental tissue [2], is a less common form of abdominal pregnancy [3]. Precise preoperative evaluation by diffusion-weighted MRI accelerates the successful minimally invasive management by LESS surgery.