Retrorectal cystic hamartoma: a problematic 'tail'

The retrorectal space is an uncommon seat for neoplastic masses. Retrorectal hamartoma or tailgut cyst (TGC) is an uncommon developmental cystic lesion occurring in this space which mostly occurs in middle-aged females. We recently cared for a 16-year-old girl who presented with vague lower abdominal pain and occasional constipation. Per rectal examination revealed an extraluminal mass bulging from posterior rectal wall. Preoperative radiological investigations revealed by suggested it to be a mature cystic teratoma. The patient underwent exploratory laprotomy with en masse excision of the cyst. Histopathological examination of the specimen showed it to be a TGC. This case highlights the possibility of a TGC as a differential for retrorectal cystic lesions and the need to completely excise them given the possibility of future malignant transformation.