Classification

Benign

Malignant

Congenital

Developmental cyst

Dermoid cyst

Epidermoid cyst

Tailgut cyst

Teratoma

Anterior meningocele

Rectal duplication

Adrenal rest tumor

Chordoma

Teratocarcinoma

Inflammatory

Granuloma

Abscess

perineal abscess

pelvirectal abscess

Fistula

Neurogenic

Neurofibroma

Neurilemmoma

Ganglioneuroma

Ependymoma

Neuro(fibro)sarcoma

Osseous

Osteoma

Sacral bone cyst

Giant cell tumor

Osteosarcoma

Chondrosarcoma

Ewing’s sarcoma

Giant cell sarcoma

Miscellaneous

Desmoid tumor

Fibroma

Leiomyoma

Lipoma

Hemangioma

Endothelioma

Pericytoma

Lymphangioma

Myelolipoma

Desmoid tumor

Metastatic disease

Fibrosarcoma

Leiomyosarcoma

Liposarcoma

Hemangioendothelial sarcoma

Carcinoid