May Be Caused by

 Common

Aneurysmal bone cyst

Bone tumor

Chordoma

Dermoid cyst

Fracture

Giant cell tumor

Hematoma

Metastasis

Myeloma

Normal variant

Pelvic surgery

Presacral abscess

Prostate carcinoma

Sarcoma

Teratoma

 Uncommon

Anterior sacral meningocele

Arachnoid cyst

Ectopic kidney

Ependymoma

Extradural cyst

Hamartoma

Hydatid cyst

Hydroureter

Intraspinal lipoma

Lymphocele

Lymphoma

Neurenteric cyst

Neurofibromatosis type 1

Neurogenic tumor

Osteomyelitis of sacrum

Ovarian cyst

Ovarian neoplasm

Rectal duplication

Tarlov cyst

Tubo-ovarian abscess

Urinoma