Surgery for Retroperitoneal Tumors in the Pelvis
The retroperitoneal tumors (RPTs) in the pelvis, also known as presacral tumors, are derived from the retroperitoneum, mostly or wholly located in the pelvic cavity, whereas excluding tumors that originate from internal organs such as the bladder, prostate, adnexa of uterus, colon, and rectum. Due to the presence of wide spaces between the pelvic peritoneum and presacral space, pelvic side walls, and pelvic diaphragm, soft tissue tumors originating from these spaces may be located posteriorly, laterally, inferiorly, or even anteriorly to peritoneum. All tumors are mostly or wholly located within true pelvis between the pelvic inlet (encircled by pubic joint, iliopubic line, and the sacral promontory) and pelvic outlet (comprised of coccyx, ischial tuberosity, and pubic arch). The tumor may partially spread to the lower abdomen and bilateral iliac fossa and even to the buttocks and perineum. 9.1% of patients with pelvic RPTs develop diffusion and metastasis, including peritoneal implantation, lymph node metastasis, and liver metastasis.