pelvic tumor pelvic tumor a pelvic tumor is any one of numerous tumors that occur in the pelvis. within the pelvis, these tumors may involve specific organs, or occupy intra-organ spaces. tumors of the presacral space and sacral space are most prevalent in children. tumors occupying specific organs have a more complex natural history. tumors occupying specific organs bladder cancer prostate cancer rectal cancer anal cancer ovarian cancer uterine cancer sacrococcygeal teratoma tumors occupying intra-organ spaces presacral space: teratoma sacral space (in approximate order of prevalence): teratoma lipoma ganglioneuroma myxopapillary ependymoma primitive neuroectodermal tumor aneurysmal bone cyst ewing's sarcoma metastases from brain stem tumors (medulloblastoma, ependymoma, high-grade astrocytoma) complications urinary incontinence fecal incontinence