Teratomas
Teratomas are a unique type of tumor that contains a variety of tissues derived from more than one of the three embryonic germ layers: ectoderm, mesoderm, and endoderm. These tumors can develop from pluripotent cells or germ cells and are classified into categories such as benign cysts (epidermoid or dermoid) or neoplasms. Although teratomas are relatively rare, their incidence varies by location; for example, sacrococcygeal teratomas occur in about 1 in 27,000 births, predominantly in girls, while intracranial teratomas make up a significant percentage of neonatal brain tumors. Symptoms of teratomas can differ based on their location, with potential effects including chronic headaches, abdominal pain, or respiratory issues. Diagnosis typically involves imaging studies and physical examinations, including fetal ultrasounds for sacrococcygeal teratomas. Treatment often involves surgical removal, and in cases of malignant transformation, may include chemotherapy or radiation. Prognosis varies significantly, depending on the tumor's size, histology, and stage at diagnosis, with some patients achieving successful outcomes through targeted treatment.
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Subject Terms
Teratomas
ALSO KNOWN AS: Germ-cell tumors, dermoid tumors
RELATED CONDITIONS: Teratocarcinomas, seminomas
DEFINITION: Teratomas are tumors containing cells derived from more than one of the three embryonic germ layers. Congenital lesions comprised of ectopic tissues arising from the ectoderm or embryologic germ cells may develop into a benign cyst, called an epidermoid or dermoid, or into a usually benign neoplasm known as a teratoma. The term teratoma also refers to any tissue located incorrectly within the body.
Risk factors: Risk factors are unclear, but they are likely due to genetic factors. In men, teratomas may be associated with other cancers, including a prior history of testicular cancer. In rare cases, the cause is iatrogenic; for example, epidermoid or dermoid cysts are possible from procedures such as therapeutic lumbar puncture that brings skin components from the surface into underlying tissue. Metastasis risk increases with a tumor stage greater than II and vascular invasion. Malignant, highly aggressive teratomas are more likely in men than in women.
Etiology and the disease process: Teratomas can contain structures such as teeth, hair, and bone. They arise from the abnormal development of pluripotent cells (cells that have not assumed their final form and function) or germ cells (cells that produce gametes—sperm or eggs) and contain cells from more than one of the three embryonic germ layers. The early embryo has three germ layers: the endoderm (which produces the lining of the digestive tube and its associated organs); the ectoderm (which produces the cells of the epidermis and nervous system); and the mesoderm (which produces the heart, kidney, ovaries, testes, and the connective tissues, including bone, muscles, and blood).
Incidence: All teratomas are relatively rare. Intracranial teratomas account for 26 to 50 percent of neonatal brain tumors. Approximately 6 percent of congenital teratomas are found in the head and neck. Germ cell tumors account for 95 percent of testicular tumors. Sacrococcygeal teratoma (found at the base of the spine in fetuses) affects 1 in 27,000 births, with the majority occurring in girls. In adults, teratomas can occur in the neck, brain, ovaries, testes, mediastinum (chest), and retroperitoneum (back of the abdominal cavity). Teratomas of the chest are most commonly diagnosed in young men in their twenties.
Symptoms: Symptoms of teratoma vary with the location and size of the tumor. Intracranial teratomas can produce chronic headaches, developmental delays, seizures, and hydrocephalus. Teratomas of the chest may be associated with difficulty breathing, chest pain, cough, and fatigue upon exercise. Ovarian teratomas are often asymptomatic, but they may be associated with abdominal or pelvic pain. Testicular teratomas may cause testicular swelling and symptoms associated with metastasis. Depending on their location, some teratomas may form a palpable or visible mass.
Screening and diagnosis: Sacrococcygeal teratomas are often diagnosed by fetal ultrasound. Other teratomas are diagnosed by physical exam and imaging studies such as a computed tomography (CT) scan, positron emission tomography (PET) scan, magnetic resonance imaging (MRI), and ultrasound. Blood tests can also test biomarkers and hormone levels. Teratomas are staged as 0, mature; I, immature; II, immature, possibly malignant; and III, malignant, or teratoma with malignant transformation. Solid teratomas are composed mostly of tissue, and cystic teratomas have pockets of fluid. Mixed teratomas are composed of cysts and tissue. Nonmalignant teratomas can still be highly aggressive and grow quickly.
Treatment and therapy: Sacrococcygeal teratoma is treated surgically. Stage I teratoma is usually treated with a combination of surgery and radiation therapy. Teratoma with malignant transformation is treated surgically, followed by radiation, chemotherapy, or both.
Prognosis, prevention, and outcomes: With sacrococcygeal teratoma, prognosis is determined by the size and histology of the tumor. These tumors can result in fatalities from secondary effects. Around one third of adult metastatic teratomas are cured with chemotherapy.
Bibliography
Carver, Brett S., Hikmat Al-Ahmadie, and Joel Sheinfeld. "Adult and Pediatric Testicular Teratoma. " The Urologic Clinics of North America, vol. 34.2, 2007, pp. 245–51.
Farci, Fabiola. “Testicular Teratoma - StatPearls.” NCBI, 23 Apr. 2023, www.ncbi.nlm.nih.gov/books/NBK567728. Accessed 23 June 2024.
Goyal, Nishant, et al. "Intracranial Teratomas in Children: A Clinicopathological Study." Child's Nervous System, vol. 29.11, 2013, pp. 2035–42.
Hambraeus, Mette et al. “Sacrococcygeal Teratoma: A Population-based Study of Incidence and Prenatal Prognostic Factors.” Journal of Pediatric Surgery, vol. 51.3, 2016, pp. 481-5, doi:10.1016/j.jpedsurg.2015.09.007.
Rescorla, Frederick J., et al. "Long-Term Outcome for Infants and Children with Sacrococcygeal Teratoma: A Report from the Children's Cancer Group." Journal of Pediatric Surgery, vol. 33.2, 1998, pp. 171–76.
Secondino, Simona, et al. "Testicular Tumors in the “Elderly” Population." Frontiers in Oncology, vol. 12, 2022, doi.org/10.3389/fonc.2022.972151. Accessed 23 Jun 2024.
Smirniotopoulos, J G, and M V Chiechi. “Teratomas, Dermoids, and Epidermoids of the Head and Neck.” Radiographics: A Review Publication of the Radiological Society of North America, Inc, vol. 15,6, 1995, pp. 1437-55, doi:10.1148/radiographics.15.6.8577967.