Neonatal teratomas.

Teratomas are composed of multiple tissues foreign to the organ or site in which they arise. Their origin is postulated by 3 theories one of which is the origin from totipotent primodial germ cells. Anatomically, teratomas are divided into gonadal or extragonadal lesions and histologically they are classified as mature or immature tumors. Teratomas are mainy isolated lesions and may occur anywhere in the body. In the neonatal age group most of these tumors are benign and occur mainly in the sacrococcygeal area followed by the anterior mediastinum. Diagnosis is usually established prenatally and may require intervention in compromised fetuses. Postnatal imaging with ultrasound, CT scan or MRI provides useful information for surgical intervention. Complete surgical excision is the treatment of choice for neonatal teratomas. Alpha feto protein is the tumor marker of choice and is particularly useful for assessing the presence of residual or recurrent disease.