<unk>  is seen in 1 in every 35,000 live births, and is the most common tumor presenting in newborn humans. Most<unk> s are found in babies and children, but<unk> s have been reported in adults and the increasingly routine use of prenatal ultrasound exams has dramatically increased the number of diagnosed<unk> s presenting in fetuses. Like other<unk> s, an<unk>  can grow very large. Unlike other<unk> s, an<unk>  sometimes grows larger than the rest of the fetus.<unk> s are the most common type of germ cell tumors (both benign and malignant) diagnosed in neonates, infants, and children younger than 4 years.<unk> s occur more often in girls than in boys; ratios of 3:1 to 4:1 have been reported. Historically,<unk> s present in 2 clinical patterns related to the child's age, tumor location, and likelihood of tumor malignancy. With the advent of routine prenatal ultrasound examinations, a third clinical pattern is emerging. * Fetal tumors present during prenatal ultrasound exams, with or without maternal symptoms.<unk> s found during routine exams tend to be small and partly or entirely external. The internal<unk> s are not easily seen via ultrasound, unless they are large enough to reveal their presence by the abnormal position of the fetal urinary bladder and other organs, but large fetal<unk> s frequently produce maternal complications which necessitate non-routine, investigative ultrasounds. * Neonatal tumors present at birth protruding from the sacral site and are usually mature or immature<unk> s. *Among infants and young children, the tumor presents as a palpable mass in the sacropelvic region compressing the bladder or rectum. These pelvic tumors have a greater likelihood of being malignant. An early survey found that the rate of tumor malignancy was 48% for girls and 67% for boys older than 2 months at the time of<unk>  tumor diagnosis, compared with a malignant tumor incidence of 7% for girls and 10% for boys younger than 2 months at the time of diagnosis. The pelvic site of the primary tumor has been reported to be an adverse prognostic factor, most likely caused by a higher rate of incomplete resection. *In older children and adults, the tumor may be mistaken for a pilonidal sinus, or it may be found during a rectal exam or other evaluation.
Sacrococcygeal teratoma
Myxoid cyst
Gonadoblastoma
Pineal gland cyst
Ectopic testis
Luteoma
Chordoma
Hydrocele testis