title: A Rare Coexistence of Retrorectal and Ovarian Cysts: A Case Report.
abstract: BACKGROUND
  Retrorectal cysts are rare benign lesions which are frequently diagnosed in middle-aged females. According to their origin and histopathologic features, retrorectal cysts are classified as squamous-lined (dermoid or epidermoid) cysts, postanal gut (tailgut) cysts, and rectal duplications (enteric or enterogenous cysts, enterocystomas). Described in this case report is an extremely unusual patient, a woman who simultaneously had a retrorectal cyst and an ovarian serous cystadenoma in addition to a long history of misdiagnosis and multiple unsuccessful surgeries.
  
  
  METHODS
  The patient was a 45-year-old female who presented with back pain, rectal fullness, constipation, and urinary symptoms. Upon her first pregnancy, a cystic pelvic mass had been misdiagnosed as an ovarian cyst. During the following 17 years, she had undergone several ineffective operations. The last CT scan and MRI studies revealed two separate noncalcified, unilocular, cystic lesions with well-defined borders in the retrorectal and retroperitoneal spaces. Two cysts were excised completely by a combined abdominoperineal approach. Pathological assessment revealed a dermoid cyst and an ovarian serous cystadenoma. No complications occurred during the 18 months of follow-up.
  
  
  CONCLUSIONS
  Coexistence of a retrorectal cyst and a serous cystadenoma is very unusual. Retrorectal cysts are rare entities that remain a difficult diagnostic and therapeutic challenge. Misdiagnosis and multiple unsuccessful surgeries are common. Complete surgical removal is the treatment of choice and requires a multidisciplinary approach in complicated cases.
authors.affiliation: Cancer Research Center, Department of Surgery, Semnan University of Medical Sciences, Semnan, IR Iran.
authors.forename: Setareh
authors.initials: S
authors.lastname: Soltany
keywords: Cyst; Epidermoid; Ovary; Rectum; Serous Cystadenoma; Tumor