A Rare Retrorectal Dilemma: Tailgut Cyst Uncovered and Excised.

Tailgut cysts are uncommon congenital lesions that develop from remnants of the embryonic hindgut. They are most frequently found in middle-aged women. This report describes a 35-year-old Indian woman who presented with a long-standing history of a painless, slowly enlarging swelling in the gluteal region. Physical examination identified a large, fluctuant mass without signs of inflammation. Pelvic magnetic resonance imaging (MRI), which is the preferred diagnostic method, revealed a multiloculated cystic lesion in the presacral space. Characteristic imaging findings included internal septations and no connection to adjacent structures. The cyst was completely removed via a retrococcygeal surgical approach. Histological examination confirmed the diagnosis of a benign tailgut cyst, showing a lining of various epithelial types with no evidence of cancer. The patient recovered well after surgery and remained asymptomatic, with no clinical evidence of recurrence, at 18 months of follow-up. This case highlights that tailgut cysts should be considered in the differential diagnosis of presacral and gluteal masses. MRI is essential for preoperative evaluation and to distinguish these cysts from other entities. Complete surgical removal is the standard treatment to prevent potential complications such as infection, recurrence, or malignant change. The retrococcygeal approach is highly successful, and timely excision is associated with a favorable outcome.