We report unusual two cases of local recurrence of villous tumor of the rectum after a transsacral excision, in which the recurrent tumor was situated outside the mucosal layer of the rectum. We believe that the lesion resulted from the implantation of tumor cells in the surgical track.
Case 1: Involved a 72-year-old woman. Previous history disclosed that she underwent excision of a rectal villous tumors 30mm in diameter via transsacral approach. Histologically it was carcinoma in adenoma. Surgical cut end was positive for adenoma. Eight years after the primary operation, a 30×30×35mm mucinous adenocarcinoma was discovered in the rectal wall accompanied with peritoneal dissemination.
Case 2: A 64-year-old man. He underwent an operation of a rectal villous tumor that was 40mm in diameter by a transsacral approach. Histology confirmed a well differentiated adenocarcinoma accompanied with no evidence of invasive malignancy. Surgical cut end was negative for adenoma and carcinoma. Three years and one month after the surgery, 40×40×35mm extrarectal adenocarcinoma was detected. It is probable that tumor cells sewn into the surgical stumups in Case 1 and the implantation of tumor cell sewn into the surgical stumps in Case 1 and the implantation of tumor cell during the first operation in Case 2 was responsible for the recurrence. And it is suggested that transsacral excision for the large rectal villous tumors with long diameter have a increased risk of developing a recurrence.