Teratomas maybe found in babies, children, and adults. Teratomas of embryonal origin are most often found in babies at birth, in young children, and, since the advent of ultrasound imaging, in fetuses.

The most commonly diagnosed fetal teratomas are sacrococcygeal teratoma (Altman types I, II, and III) and cervical (neck) teratoma. Because these teratomas project from the fetal body into the surrounding amniotic fluid, they can be seen during routine prenatal ultrasound exams. Teratomas within the fetal body are less easily seen with ultrasound; for these, MRI of the pregnant uterus is more informative.

Teratomas are not dangerous for the fetus unless there is either a mass effect or a large amount of blood flow through the tumor (known as "vascular steal"). The mass effect frequently consists of obstruction of normal passage of fluids from surrounding organs. The vascular steal can place a strain on the growing heart of the fetus, even resulting in heart failure, and thus must be monitored by fetal echocardiography.

Teratomas can cause an autoimmune illness called Anti N-methyl-D-aspartate (NMDA) Receptor Encephalitis. After surgery, there is a risk of regrowth in place, or in nearby organs.

SCT is seen in 1 in every 35,000 live births, and is the most common tumor presenting in newborn humans. Most SCTs are found in babies and children, but SCTs have been reported in adults and the increasingly routine use of prenatal ultrasound exams has dramatically increased the number of diagnosed SCTs presenting in fetuses. Like other teratomas, an SCT can grow very large. Unlike other teratomas, an SCT sometimes grows larger than the rest of the fetus.

Sacrococcygeal teratomas are the most common type of germ cell tumors (both benign and malignant) diagnosed in neonates, infants, and children younger than 4 years. SCTs occur more often in girls than in boys; ratios of 3:1 to 4:1 have been reported.

Historically, sacrococcygeal teratomas 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. SCTs found during routine exams tend to be small and partly or entirely external. The internal SCTs 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 SCTs 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 teratomas.

- 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 sacrococcygeal 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.

Neurocutaneous melanosis is associated with the presence of either giant congenital melanocytic nevi or non-giant nevi of the skin. It is estimated that neurocutaneous melanosis is present in 2% to 45% of patients with giant congenital melanocytic nevi. Patients with non-giant congenital melanocytic nevi seem to have a much lower, but undefined risk. Of these patients, only a small number are symptomatic, usually displaying symptoms before the age of 2.

These symptoms are the result of melanocytic lesions being present in the leptomeninges of the central nervous system.

Symptoms can include:

- Papilledema

- Cranial palsies

- Headache

- Vomiting

- Seizures

Others symptoms may also exist that are related to an increase in intracranial pressure. These symptoms seem to be present regardless of the malignancy of the melanin deposits within the central nervous system.

Approximately 10% of patient with neurocutaneous melanosis also present the Dandy–Walker syndrome and associated Dandy-Walker malformation. This malformation involves an enlargement of the posterior fossae and fourth ventricle along with agenesis of the cerebellar vermis. The abnormalities of the leptomeninges during fetal development due to neurocutaneous melanosis may be the cause of this increased incidence of the Dandy-Walker malformation. The development of hydrocephalus is the most common symptom associated with a combination of neurocutaneous melanosis and a Dandy-Walker malformation, occurring in about two out of three patients.

Due to its classification, a dermoid cyst can occur wherever a teratoma can occur.

An immature teratoma is a rare type of malignant (cancerous) germ cell tumor (type of tumor that begins in the cells that give rise to sperm or eggs).

Like a mature teratoma, it contains several different types of tissue such as hair, muscle, and bone. Unlike a mature teratoma, it contains primitive neuroepithelium.

Symptoms are assessed on a case by case basis. Some cysts in the CNS can be asymptomatic (producing or showing no symptoms), depending on their location in the brain or spinal cord. If the cysts develop in critical areas of the central nervous system, they can present one or more of the following symptoms:

- Pressure in the spinal cord or brain

- Rupture of nerves around the cyst

- Weakness in specific parts of the body controlled by the cyst-infected brain region

- Inflammation

- Hydrocephalus

- Brainstem hemorrhage

- Seizures

- Visual disturbances and hearing Loss

- Headache

- Difficulty with balance or walking

In general, symptoms vary depending on the type of cyst and its location within the CNS.

Sacrococcygeal teratoma (SCT) is a type of tumor known as a teratoma that develops at the base of the coccyx (tailbone) and is thought to be derived from the primitive streak. Sacrococcygeal teratomas are benign 75% of the time, malignant 12% of the time, and the remainder are considered "immature teratomas" that share benign and malignant features. Benign sacrococcygeal teratomas are more likely to develop in younger children who are less than 5 months old, and older children are more likely to develop malignant sacrococcygeal teratomas. The Currarino triad (OMIM 176450), due to an autosomal dominant mutation in the MNX1 gene, consists of a presacral mass (usually a mature teratoma or anterior meningocele), anorectal malformation and sacral dysgenesis.

A dermoid cyst is a teratoma of a cystic nature that contains an array of developmentally mature, solid tissues. It frequently consists of skin, hair follicles, and sweat glands, while other commonly found components include clumps of long hair, pockets of sebum, blood, fat, bone, nails, teeth, eyes, cartilage, and thyroid tissue.

As dermoid cysts grow slowly and contain mature tissue, this type of cystic teratoma is nearly always benign. In those rare cases wherein the dermoid cyst is malignant, a squamous cell carcinoma usually develops in adults, while infants and children usually present with an endodermal sinus tumor.

This category of cysts takes over areas of necrotic tissue in the brain from injuries, diseases, or abnormalities, which occur due to the central nervous system's nonregenerative nature. These cysts can affect all germ layers of the CNS, but are most common in the arachnoid mater, and the ventricular space, which may block CSF pathways. These cysts can be static (stationary) or progressive. Some examples of cysts originating from the CNS tissue include:

- Arachnoid cysts (Leptomeningeal cysts)

- Ependymal cysts

- Cystic cerebellar astrocytomas

- Colloid cysts

Source:

- severe headache

- visual loss (due to papilledema)

- vomiting

- bilateral Babinski sign

- drowsiness (after several hours of the above symptoms)

- gait change (rotation of feet when walking)

- impaction/constipation

- back flexibility

Ectomesenchymoma is a rare, fast-growing tumor of the nervous system or soft tissue that occurs mainly in children, although cases have been reported in patients up to age 60. Ectomesenchymomas may form in the head and neck, abdomen, perineum, scrotum, or limbs. Also called malignant ectomesenchymoma.

Malignant ectomesenchymoma (MEM) is a rare tumor of soft tissues or the CNS, which is composed of both neuroectodermal elements [represented by ganglion cells and/or well-differentiated or poorly differentiated neuroblastic cells such as ganglioneuroma, ganglioneuroblastoma, neuroblastoma, peripheral primitive neuroectodermal tumors – PNET] and one or more mesenchymal neoplastic elements, usually rhabdomyosarcoma . The most accepted theory suggests that this tumor arises from remnants of migratory neural crest cells and thus from the ectomesenchyme.

Neurocutaneous melanosis is a congenital disorder characterized by the presence of congenital melanocytic nevi on the skin and melanocytic tumors in the leptomeninges of the central nervous system. These lesions may occur in the amygdala, cerebellum, cerebrum, pons, and spinal cord of patients. Although typically asymptomatic, malignancy occurs in the form of leptomeningeal melanoma in over half of patients. Regardless of the presence of malignancy, patients with symptomatic neurocutaneous melanosis generally have a poor prognosis with few treatment options. The pathogenesis of neurocutaneous melanosis is believed to be related to the abnormal postzygotic development of melanoblasts and mutations of the NRAS gene.

The tumor largely affects children under 15 years of age and about 20% only are found in adults with nearly 60% involving males and 40% females (1). The most frequent locations are head and neck (orbit and nasopharynx), central nervous system, abdomen and retroperitoneum, pelvis, perineum, scrotum and prostate(1). Clinical symptoms are not specific and usually caused by local tumor compression and infiltration.

A ganglioneuroma is typically asymptomatic, and is typically only discovered when being examined or treated for another condition. Any symptoms will depend upon the tumor's location and the nearby organs affected.

For example, a tumor in the chest area may cause breathing difficulty, chest pain, and trachea compression. If the tumor is located lower in the abdomen, it may cause abdominal pain and bloating. A tumor near the spinal cord may cause spinal deformity or spinal compression, leading to pain and loss of muscle control or sensation in the legs and/or arms.

These tumors may produce certain hormones, which can cause diarrhea, an enlarged clitoris (in females), high blood pressure, increased body hair, and sweating.

The histology of EST is variable, but usually includes malignant endodermal cells. These cells secrete alpha-fetoprotein (AFP), which can be detected in tumor tissue, serum, cerebrospinal fluid, urine and, in the rare case of fetal EST, in amniotic fluid. When there is incongruence between biopsy and AFP test results for EST, the result indicating presence of EST dictates treatment. This is because EST often occurs as small "malignant foci" within a larger tumor, usually teratoma, and biopsy is a sampling method; biopsy of the tumor may reveal only teratoma, whereas elevated AFP reveals that EST is also present. GATA-4, a transcription factor, also may be useful in the diagnosis of EST.

Diagnosis of EST in pregnant women and in infants is complicated by the extremely high levels of AFP in those two groups. Tumor surveillance by monitoring AFP requires accurate correction for gestational age in pregnant women, and age in infants. In pregnant women, this can be achieved simply by testing maternal serum AFP rather than tumor marker AFP. In infants, the tumor marker test is used, but must be interpreted using a reference table or graph of normal AFP in infants.

They are exceptionally associated with hypercalcemia. On gross examination, dysgerminomas present with a smooth, bosselated (knobby) external surface, and is soft, fleshy and either cream-coloured, gray, pink or tan when cut. Microscopic examination typically reveals uniform cells that resemble primordial germ cells. Typically, the stroma contains lymphocytes and about 20% of patients have sarcoid-like granulomas.

Metastases are most often present in the lymph nodes.

The symptoms of choroid plexus carcinoma are similar to those of other brain tumors. They include:

- Persistent or new onset headaches

- Macrocephaly or bulging fontanels in infants.

- Loss of appetite (refusal to take food in infants)

- Papilledema

- Nausea and emesis

- Ataxia

- Strabismus

- Developmental delays

- Altered mental status

A dysgerminoma is a type of germ cell tumor; it usually is malignant and usually occurs in the ovary.

A tumor of the identical histology but not occurring in the ovary may be described by an alternate name: seminoma in the testis or germinoma in the central nervous system or other parts of the body.

Dysgerminoma accounts for less than 1% of ovarian tumors overall. Dysgerminoma usually occurs in adolescence and early adult life; about 5% occur in pre-pubertal children. Dysgerminoma is extremely rare after age 50. Dysgerminoma occurs in both ovaries in 10% of patients and, in a further 10%, there is microscopic tumor in the other ovary.

Abnormal gonads (due to gonadal dysgenesis and androgen insensitivity syndrome) have a high risk of developing a dysgerminoma. Most dysgerminomas are associated with elevated serum lactic dehydrogenase (LDH), which is sometimes used as a tumor marker.

Endodermal sinus tumor (EST), also known as yolk sac tumor (YST), is a member of the germ cell tumor group of cancers. It is the most common testicular tumor in children under 3, and is also known as infantile embryonal carcinoma. This age group has a very good prognosis. In contrast to the pure form typical of infants, adult endodermal sinus tumors are often found in combination with other kinds of germ cell tumor, particularly teratoma and embryonal carcinoma. While pure teratoma is usually benign, endodermal sinus tumor is malignant.

Ependymoma is a tumor that arises from the ependyma, a tissue of the central nervous system. Usually, in pediatric cases the location is intracranial, while in adults it is spinal. The common location of intracranial ependymoma is the fourth ventricle. Rarely, ependymoma can occur in the pelvic cavity.

Syringomyelia can be caused by an ependymoma.

Ependymomas are also seen with neurofibromatosis type II.

Hemangioblastomas (or haemangioblastomas, see spelling differences) (capilliary hemangioblastomas) are tumors of the central nervous system that originate from the vascular system usually during middle-age. Sometimes these tumors occur in other sites such as the spinal cord and retina. They may be associated with other diseases such as polycythemia (increased blood cell count), pancreatic cysts and Von Hippel-Lindau syndrome (VHL syndrome). Hemangioblastomas are most commonly composed of stromal cells in small blood vessels and usually occur in the cerebellum, brain stem or spinal cord. They are classed as grade one tumors under the World Health Organization's classification system.

Ganglioneuroma is a rare and benign tumor of the autonomic nerve fibers arising from neural crest sympathogonia, which are completely undifferentiated cells of the sympathetic nervous system. However, ganglioneuromas themselves are fully differentiated neuronal tumors that do "not" contain immature elements.

Ganglioneuromas most frequently occur in the abdomen, however these tumors can grow anywhere sympathetic nervous tissue is found. Other common locations include the adrenal gland, paraspinal retroperitoneum, posterior mediastinum, head, and neck.

There are few early warning signs that a patient has a DSRCT. Patients are often young and healthy as the tumors grow and spread uninhibited within the abdominal cavity. These are rare tumors and symptoms are often misdiagnosed by physicians. The abdominal masses can grow to enormous size before being noticed by the patient. The tumors can be felt as hard, round masses by palpating the abdomen.

First symptoms of the disease often include abdominal distention, abdominal mass, abdominal or back pain, gastrointestinal obstruction, lack of appetite, ascites, anemia, and/or cachexia.

Other reported symptoms include unknown lumps, thyroid conditions, hormonal conditions, blood clotting, kidney or urological problems, testicle, breast, uterine, vaginal, or ovarian masses.

Despite their name, germ cell tumors occur both within and outside the ovary and testis.

- head

- inside the cranium — pineal and suprasellar locations are most commonly reported

- inside the mouth — a fairly common location for teratoma

- neck

- mediastinum — account for 1% to 5% of all germ cell neoplasms

- pelvis, particularly sacrococcygeal teratoma

- ovary

- testis

In females, germ cell tumors account for 30% of ovarian tumors, but only 1 to 3% of ovarian cancers in North America. In younger women germ cell tumors are more common, thus in patients under the age of 21, 60% of ovarian tumors are of the germ cell type, and up to one-third are malignant. In males, germ cell tumors of the testis occur typically after puberty and are malignant (testicular cancer). In neonates, infants, and children younger than 4 years, the majority of germ cell tumors are sacrococcygeal teratomas.

Males with Klinefelter syndrome have a 50 times greater risk of germ cell tumors (GSTs). In these persons, GSTs usually contain nonseminomatous elements, present at an earlier age, and seldom are gonadal in location.