Vestigial retrorectal cystic tumors in adults: a review of 30 cases.

Objectives: Retrorectal tumors are uncommon. This is a report on a series of vestigial retrorectal cystic tumors in adults that were surgically removed at two medical centers in France. We also assessed the significance of imaging and, in particular, magnetic resonance imaging (MRI) in the management of these lesions.

Methods: The medical files of adult patients operated on for vestigial retrorectal cystic tumors over the past 15 years were retrospectively studied and, in particular, the radiological studies, the treatment and the histopathology.

Results: Thirty patients underwent surgery for vestigial retrorectal cystic tumor. A preoperative diagnosis was possible in almost all cases. The surgical procedure was justified by preoperative imaging and included the transanal approach (three cases), posterior approach (23 cases), anterior approach (two cases) and combined posterior and anterior approach (two cases). Imaging can identify a multilobular lesion that may require the use of a coccygeal approach to achieve complete resection. During a mean follow-up of 3.2 years (range 0.5-15 years), two patients had a local recurrence (successfully surgically removed), and a further two patients were lost to follow-up. Only one lesion was malignant.

Conclusions: Preoperative imaging, and especially magnetic resonance imaging, enables both a specific diagnosis and the selection of the optimal surgical procedure for the treatment of vestigial retrorectal cystic tumors in adults.