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.

Polyembryoma is a rare, very aggressive form of germ cell tumor usually found in the ovaries. Polyembryoma has features of both yolk sac tumour and undifferentiated teratoma/embryonal carcinoma, with a characteristic finding of embryoid bodies lying in a loose mesenchymal stroma.

It has been found in association with Klinefelter syndrome.

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.

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.

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.

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.

A Sertoli cell nodule, also Pick's adenoma, testicular tubular adenoma and tubular adenoma of the testis, is a benign proliferation of Sertoli cells that arises in association with cryptorchidism (undescended testis). They are not composed of a clonal cell population, i.e. neoplastic; thus, technically, they should not be called an "adenoma".

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.

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.

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 struma ovarii (literally: goitre of the ovary) is a rare form of monodermal teratoma that contains mostly thyroid tissue, which may cause hyperthyroidism.

Despite its name, struma ovarii is not restricted to the ovary.

The vast majority of struma ovarii are benign tumors; however, malignant tumors of this type is found in a small percentage of cases.

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

GCNIS is seen in the following settings:

- Almost all invasive germ cell tumours of the testis in adults

- Fifty percent of patients with GCNIS developed invasive germ cell tumours within five years of initial diagnosis.

- Five percent of contralateral testes in men with a history of prior testicular germ cell tumour.

- Less than five percent of cryptorchid testes.

- Less than one percent of patients with infertility.

A germ cell tumor (GCT) is a neoplasm derived from germ cells. Germ cell tumors can be cancerous or non-cancerous tumors. Germ cells normally occur inside the gonads (ovary and testis). Germ cell tumors that originate outside the gonads may be birth defects resulting from errors during development of the embryo.

Not all germ cell tumors (GCTs) arise from "intratubular germ cell neoplasia". The following testicular GCTs do not arise from ITGCN:

- Spermatocytic seminoma

- Pediatric Yolk sac tumors (endodermal sinus tumour). This is currently an area of controversy as some authors dispute the absence of ITGCN in these cases.

- Teratoma (rare exceptions)

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.

Individuals presenting with fibrosarcoma are usually adults aged thirty to fifty five years, often presenting with pain. In adults, males have a higher incidence for fibrosarcoma than females.

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

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.

The tumor may present different degrees of differentiation: low grade (differentiated), intermediate malignancy and high malignancy (anaplastic). Depending on this differentiation, tumour cells may resemble mature fibroblasts (spindle-shaped), secreting collagen, with rare mitoses. These cells are arranged in short fascicles which split and merge, giving the appearance of "fish bone" known as a herringbone pattern. Poorly differentiated tumors consist in more atypical cells, pleomorphic, giant cells, multinucleated, numerous atypical mitoses and reduced collagen production. Presence of immature blood vessels (sarcomatous vessels lacking endothelial cells) favors the bloodstream metastasizing. There are many tumors in the differential diagnosis, including spindle cell melanoma, spindle cell squamous cell carcinoma, synovial sarcoma, leiomyosarcoma, malignant peripheral nerve sheath tumor and biphenotypic sinonasal sarcoma.

The strumal carcinoid is a type of monodermal teratoma with histomorphologic features of (1) the thyroid gland and (2) a neuroendocrine tumour (carcinoid).

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.

Gonadoblastoma is most often associated with an abnormal chromosomal karyotype, gonadal dysgenesis, or the presence of a Y chromosome in over 90% of cases. Gonadoblastoma has been found in association with androgen insensitivity syndrome, mixed gonadal dysgenesis and Turner syndrome, especially in the presence of Y chromosome-bearing cells.

Gonadoblastomas can contain elements of both germ cells and gonadal stroma.

Formerly, gonadoblastoma was sometimes regarded as a subset of dysgerminoma. In modern literature, it is sometimes considered to progress to dysgerminoma.