Abstract
Background: Tailgut cysts are rare congenital malformation lesions, also known as retrorectal cystic hamartoma is defined as a remnant part of postnatal hindgut. Because of their rare incidence and nonspecific presentation, tailgut cysts are misdiagnosed. The symptoms depend on the size and the location of the tumor. Surgical intervention is always required because of the complications of these tumors.
Case Presentation: We report a 40-year-old female patient with an uneventful past surgical and medical history. Presented to the outpatient clinic with vague abdominal pain and constipation for 1 and a half years. The rectal digital examination, computed tomography abdomen, and pelvis with contrast and magnetic resonance imaging pelvis indicated the presence of the tailgut cyst, intraoperative we found two retrorectal cysts, and complete surgical resection using a posterior approach was performed. The histopathology examination showed a 5 * 5 cm cyst filled with putty-like material, defined as an epidermal inclusion cyst. The patient recovered well and was discharged 6 days after surgery. Out patient clinic follow up was uneventful and the patient was discharged from the surgical side.
Conclusion: Tailgut cysts originate from the postanal gut of the embryo. These cysts are typically asymptomatic, surgical removal via a posterior or anterior approach is recommended once these lesions are detected due to the possibility of malignant development, infection, retrorectal abscesses formation, and rarely anal fistulas.
A variety of surgical techniques can be employed, and the course of treatment can be customized to fit the anatomy and suspected lesion diagnosis of each patient.

Key words: Tailgut cyst, retrorectal tumor, retrorectal cystic hamartoma, retrorectal cystic hamartoma.