Immunohistochemical diagnostic confirmation and laparoscopic treatment for primary peritoneal pregnancy: A case report

Abstract

We report a case of primary peritoneal pregnancy treated with laparoscopic surgery in a 24-year-old gravida 0 who was referred to our hospital with lower abdominal pain. Transvaginal ultrasonography did not reveal a gestational sac in the pelvis; however, a hyperechoic lesion suspicious for a pelvic hematoma was identified in the cul-de-sac. Her serum human chorionic gonadotropin (hCG) level was 6400 mIU/mL, and serum hemoglobin was 11.0 g/dL. Physical examination showed signs of peritoneal irritation. We performed laparoscopy, which revealed an unremarkable uterus, bilateral fallopian tubes, and bilateral ovaries. We collected 500 mL of blood from the abdominopelvic cavity, and evaluation revealed a peritoneal pregnancy with active bleeding. We removed the gestational tissue, and histopathological examination of the retrieved specimen confirmed villi. Her serum hCG level immediately decreased postoperatively. Finally, she was histopathologically diagnosed with a peritoneal pregnancy because syncytiotrophoblasts were observed adjacent to the peritoneum of the pouch of Douglas, following staining with collagen type IV, which is derived from the mesothelium.