Abstract
Recently, imaging studies have markedly improved the preoperative diagnostic accuracy. However, the intraoperative diagnosis differs from the preoperative diagnosis in certain cases. We report a case of retroperitoneal schwannoma that was preoperatively diagnosed as an ovarian tumor, wherein the tumor location was determined by laparoscopy and the application of pressure on the abdominal wall. A 48-year-old woman (gravida: 3, para: 3) presented with lower abdominal discomfort. Ultrasonography and magnetic resonance imaging (MRI) indicated the presence of bilateral multicystic ovarian tumors in her right and left ovaries (diameters: 75 mm and 31 mm, respectively). Hence, she was referred to our hospital for treatment. Although the right ovarian tumor could be clearly observed by transvaginal ultrasonography, the left ovarian tumor could not be identified due to its relatively smaller size. Laboratory values, including the levels of CA19-9, CA125, and CEA, were normal. Nevertheless, she was diagnosed as having bilateral ovarian tumors, and laparoscopic surgery was performed for treatment. Laparoscopic observation indicated a 75-mm tumor in the right ovary, but showed normal appearance of the left ovary. After laparoscopic bilateral salpingo-oophorectomy was performed, as the left ovary tumor diagnosed on preoperative MRI remained unidentified, pressure was applied on the abdominal wall adjacent to the site where the left ovary tumor was suspected, and the site was laparoscopically observed. Accordingly, a retroperitoneal schwannoma was accurately identified, and was completely resected thereafter via laparotomy with a minimal incision. The histological diagnosis was schwannoma of the femoral nerve.
