Myxoid Degenerated Giant Rectal Schwannoma Masquerading as Tailgut Cyst: A Rare Case Report

Abstract

Background: Colorectal schwannomas are rare tumors often detected incidentally and frequently misdiagnosed on preoperative evaluation. They can grow to a large size and create a significant mass effect. A rare case of large rectal Schwannomas mimicking tailgut cyst and managed by a laparoscopic approach is described in the present report. Case Presentation: A 48- year-old gentleman presented with urinary retention and constipation. Examination revealed an ill-defined hard mass in the left iliac fossa extending to the pelvis. Imaging revealed a 18x12x 9 cm cystic lesion suggestive of a tailgut cyst. The patient underwent Hand-assisted laparoscopic excision of the lesion. The tumor showed spindle cells with myxoid degeneration on microscopic examination and S-100 positivity in immunohistochemistry suggestive of Schwannoma. His postoperative course was uneventful, and there is no evidence of tumor recurrence at eight months of follow-up.  Conclusion: Rectal Schwannoma with myxoid degeneration can mimic tailgut cyst and pose a diagnostic challenge. The hand-assisted laparoscopic approach is feasible for excision of large rectal schwannomas.