Retrorectal tumors.

Retrorectal or presacral tumors are rare and can be challenging to diagnose and treat. Because the retrorectal space contains multiple embryologic remnants derived from various tissues, the tumors that develop in this space are heterogeneous. Most lesions are benign, but malignant neoplasms are not uncommon. Lesions are classified as congenital, neurogenic, osseous, inflammatory, or miscellaneous. Although treatment depends on diagnosis and anatomic location, most retrorectal lesions will require surgical resection.