May Be Caused by

 Common

Aneurysmal bone cyst

Chondrosarcoma

Chordoma

Ewing sarcoma

Giant cell tumor

Lymphoma

Metastasis to sacrum

Multiple myeloma

Neurofibroma

Notochordal rest

Plasmacytoma

Sacrococcygeal teratoma

Schwannoma

 Uncommon

Fibrosarcoma

Malignant fibrous histiocytoma

Malignant giant cell tumor

Malignant peripheral nerve sheath tumor

Neuroblastoma

Osteoblastoma

Osteochondroma

Osteoma

Osteosarcoma

Paget sarcoma

Radiation-induced sarcoma