<unk>  <unk>  is a type of tumor known as a<unk>  that develops at the base of the coccyx (tailbone) and is thought to be derived from the primitive streak.<unk> s are benign 75% of the time, malignant 12% of the time, and the remainder are considered "immature<unk> s" that share benign and malignant features. Benign<unk> s are more likely to develop in younger children who are less than 5 months old, and older children are more likely to develop malignant<unk> s. The Currarino triad, due to an autosomal dominant mutation in the MNX1 gene, consists of a presacral mass (usually a mature<unk>  or anterior meningocele), anorectal malformation and sacral dysgenesis.
Sacrococcygeal teratoma
Myxoid cyst
Gonadoblastoma
Pineal gland cyst
Ectopic testis
Luteoma
Chordoma
Hydrocele testis