Tehran University of Medical Sciences Archives of Anesthesiology and Critical Care 2423-5849 11 Supp. 1 2025 04 05 780 782 Alireza Babajani Department of Anesthesiology, School of Allied Medical Sciences, Alborz University of Medical Sciences, Karaj, Iran. Fahime Kazemi Imam Khomeini Hospital, Zahedan University of Medical Sciences, Khash, Iran. Shaqayeq Taghizadeh Department of Anesthesia, Faculty of Paramedical Sciences, Guilan University of Medical Sciences, Rasht, Iran. Atiyeh Sadat Sajadi Department of Anesthesia Technology, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran. Seyyedeh Haniyeh Mousavibaghi Department of Operating Room, Faculty of Paramedical Sciences, Guilan University of Medical Sciences, Rasht, Iran. 2024 12 08 2024 12 22 Gossypiboma is a rare mass caused by surgical instruments left in the body after surgery. A 21-year-old woman with a history of two cesarean sections presented with abdominal pain; initially, she suspected appendicitis. Unexpectedly an ultrasound showed bleeding ovarian cysts and a radiopaque line that looked like surgical sponge that had been left behind. This discovery led to immediate hospitalization and subsequent laparotomy. During surgical intervention, the medical team encountered a hemorrhagic ovarian cyst with a significant mass of tissue with a diameter of 8 cm. Despite carefully exploring the surgical site, the team did not immediately find the suspected surgical sponge. Further investigation revealed nothing, but a detailed dissection of the mass-like tissue ultimately uncovered the sponge inside. https://aacc.tums.ac.ir/index.php/aacc/article/view/1154