Completeness of Excision and Persistent Residual Disease in Retrorectal Cysts: A Single-Center Experience

Background Retrorectal cysts are rare congenital lesions with malignant potential, and incomplete excision may result in persistent residual disease. Factors associated with persistent residual disease after surgical excision remain poorly defined. Methods We retrospectively reviewed 23 patients diagnosed with retrorectal cystic lesions between 2009 and 2024. Demographic, radiological, surgical, histopathological, and follow-up data were analyzed. Among the 16 surgically treated patients, median follow-up was 39 months (range, 12-60). Results The cohort included 16 women (69.6%) and 7 men, with a median age of 49 years. Diagnosis was based on CT in 14 patients (60.9%) and MRI in 9 (39.1%). Sixteen patients underwent surgery: 6 underwent open transabdominal resection, 5 laparoscopic resection, and 5 posterior (Kraske) resection. Postoperative complications occurred in 6 patients (37.5%), including wound complications, seroma, bleeding, and urinary dysfunction; no postoperative mortality was observed. Histopathology showed tailgut cyst components in most cases and in both malignant lesions. Persistent residual disease was identified in 5 patients (31.3%). Retrospective review of preoperative imaging demonstrated previously existing cystic components that had not been completely excised, most commonly adjacent to the levator ani muscle. Conclusion Complete excision of all cystic extensions may be more important than the surgical approach in preventing persistent residual disease. Careful preoperative MRI assessment, recognition of extensions near the levator ani muscle, and meticulous surgical planning may help reduce the risk of persistent residual disease.