Fact-sheet: Tailgut cyst
Updated on 03/09/2026 at 10:41 AM
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Definition
Tailgut cyst corresponds to the persistence of an embryonic remnant of the primitive gut (vestigial cyst).
Clinical features
Often an incidental finding in middle-aged women.
May become superinfected.
CT
Retrorectal cystic lesion located above the anorectal region.
To be characterized by MRI
MRI
Reference examination.
Often a multicystic lesion with small cysts adherent to a main cyst.
Possible T1 and T2 hyperintense content in cases of proteinaceous or mucinous content.
Location: Retrorectal lesion generally located above the anorectal region, very rarely arising primarily in the ischioanal fossa. A large tailgut cyst may extend into the ischioanal fossa.
No enhancement after gadolinium injection, except in cases of complications such as infection or degeneration (rarely mucinous adenocarcinoma).
Management
En bloc excision.
Do not perform puncture.
Differential diagnosis
- Abscess
- Other tumor of the perirectal space