Retrorectal cystic hamartoma: A case report.

Introduction: and importance: Retrorectal cystic hamartoma (RCH) is a rare congenital lesion of the presacral space, which is part of the vestigial cystic tumors often benign and predominantly in women. Generally asymptomatic, the appearance of symptoms such as pain or neurological disorders should raise suspicion of degeneration.

Case Presentation: We report an unusual observation of a 62-year-old patient admitted for perineal pain evolving for 2 months associated with tenesma and chronic constipation. The digital rectal examination found a posterior bulge at 4 cm from the anal margin, without intraluminal lesion. Rectosigmoidoscopy had noted posterior extrinsic compression but no rectal tumor. Pelvic CT and MRI had shown a solidocystic formation of the retro-rectal and presacral spaces, related to an enteric cyst. The operation was performed by abdominal approach and the surgical exploration had found a bilobed cystic formation. The cystic mass was removed and the anatomopathological examination concluded that it was a cystic hamartoma with no sign of malignancy.

Clinical Discussion: Retrorectal tumors develop in the space bounded anteriorly by the propria fascia of the rectum and posteriorly by the presacral fascia overlying the sacrum. Common in children and then often malignant, inversely, in adults, they are rare and most often benign tumors. They are generally asymptomatic with a predominance of females, unlike our observation where the patient was male with a symptomatology dominated by perineal pain and constipation. The discovery is incidental in the majority of cases, however, in some cases, these cysts may be revealed by complications. The lesion can be explored by transrectal or suprapubic ultrasound, MRI and CT scan. Rectoscopy and fistulography may complete the exploration in case of diagnostic doubt. The resection must be thorough and in monobloc because of the risk of recurrence and the approach depends on the location and the size of the lesion.

Conclusion: RCH is a rare benign lesion whose morphological characteristics seem quite stereotyped. A detailed postoperative anatomopathological examination allows the diagnosis to be made and, above all, to look for a site of malignant transformation. This is why a complete surgical removal is necessary to prevent recurrence.