[Tailgut cyst. Rare differential diagnosis of retrorectal tumors].

Tumors of the retrorectal space are rare entities. The case report of a retrorectal tailgut cyst serves to illustrate the clinical and diagnostic findings, differential diagnosis, and therapy of retrorectal tumors. Tumors in this area can be identified by palpation. The subsequent investigations include ultrasound, endosonography, endoscopy, and by choice computed tomography or magnetic resonance imaging. Usually tailgut cysts are characterized as cystic tumors, well delineated with multicystic formation. The diagnosis has to differentiate between carcinomas of the colorectum, hamartomas, lymphomas, teratomas, chordomas, abscess formation, dermoid cysts, epidermoid cysts, and enteral cysts. An elevated level of CEA may point to malignancy. Complete surgical resection is the therapy of choice.