Abstract
A 30-year-old woman complaining of a left lower abdominal tumor was suspected to have an ovarian cyst by abdominal CT scan elsewhere and then underwent laparotomy at a gynecological hospital. However, no abnormal findings were seen at the ovary and she was referred to our hospital. Following abdominal US, CT and MRI, she was diagnosed as having a retroperitoneal cyst and was operated on. The tumor was present in the retroperitoneum, from caudad to the left kindney to dorsal aspect of the descending colon. So the retroperitoneum was incised and the tumor was removed. The removed tumor was 17 × 12 × 10cm in dimension and elastic soft. Incision of the tumor yielded 660cc of serous fluid, and it was an almost homogeneous monolocular cyst. Histopathologically it was a cyst covered with monolayer ciliated epithelium, in which there were cells looked like interstitial cells of the ovarian tube and salpingian like endocrine cells concomitantly, with a part of incomplete smooth muscle fascicle. Thus the definite diagnosis of a cyst of retroperitoneal müllerian duct was made from these findings including immunohistological findings.
