Fig. 2

a The retroperitoneum was dissected caudally from the promontrium using a medial approach, and the rectal mesentery was dissected. After mesenteric mobilization, a well-defined mass was revealed in the presacral space. b Detachment was performed, except for the anterior aspect of the sacrum. c Dorsal detachment in contact with the front of the sacrum was performed last. The tumor was resected en bloc without any exposure