Tailgut cyst. Case report

Tailgut cyst is a rare congenital presacral lesion with specific histological features, of mixed stratified and cylindriform ciliated epithelia which allow a clear differential diagnosis with other developmental lesions located in the pelvis. Often asymptomatic, the cyst can determine compression on the surrounding organs, infection or bleeding. The case reported is a 52-year-old man with history of previous interventions for recurrent cystic teratoma. Palpable mass at digital rectal examination was evident with clinical features of external compression. Ultrasounds revealed a 10 cm large cystic retrorectal lesion which was as well confirmed by MR. Endoscopy showed a compression on the posterior aspect of the rectum, with no signs of primary rectal involvement. Increased CA 19.9 and CA125 were observed. Surgery was carried out with open "en bloc" resection of the retrorectal mass. Histology showed typical double epithelium supporting the diagnosis of tailgut cyst. Ultrasounds followed by MR or CT are the main diagnostic methods. Although rare, a possible malignant transformation within the cyst has been reported, for this reason and for symptoms control, surgery is often indicated. In common experience nerve sparing technique through an anterior approach is a demanding but safe procedure with low recurrence rate.