Beyond the newborn period, symptoms of teratomas depend on its location and organ of origin. Symptoms are caused by extension and interference with surrounding tissue and organs. They may extend into the pelvis and abdominal cavity causing compression and obstruction of internal organs, and interruption of blood flow in the region [8]. Symptoms may include [6]:

• Pain: abdominal, epigastric, lower lumbar, head, and neck
• Palpable mass found on physical examination
• Visible tumor 

Teratomas most often have a midline presentation. Sacrococcygeal teratomas account for approximately 40% of all teratomas [3]. Other common locations include the gonads, anterior mediastinum, and retroperioneum. Even less frequently they appear in the brain, heart, pharynx and pleura [8].

• Pain

  Two patients presented with abdominal pain and two of the three underwent a laparoscopic adrenalectomy. [ncbi.nlm.nih.gov]

  Aside from a visible mass, symptoms include: constipation abdominal pain painful urination swelling in the pubic region leg weakness They’re found more often in infant girls than boys. [healthline.com]

• Weakness

  Leg weakness. Abdominal pain and constipation. [blog.cognifit.com]

  Tumours with a large presacral component may present with lower extremity weakness or paralysis, constipation, abdominal distension, and urinary tract symptoms secondary to bladder outlet obstruction. 56-58 Isolated cases of lower extremity weakness or [pmj.bmj.com]

• Pathologist

  Samples are collected for further examination by a pathologist Tissue biopsy from the affected lung: A biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. [dovemed.com]

  These rare but important findings will provide additional, potential therapeutic strategies for gynecologists, neurosurgeons, and pathologists. [ncbi.nlm.nih.gov]

  The Archives of Pathology & Laboratory Medicine is published monthly by the College of American Pathologists, and is an official publication of the College of American Pathologists. [archivesofpathology.org]

  This eponym exists despite the fact that five years prior to Wilms’ manuscript the German pathologist Felix V. [healio.com]

  © American Society of Clinical Pathologists Related articles in PubMed [doi.org]

• Anemia

  Investigations: Detailed ultrasound examination, including echocardiography for assessment of cardiac function and measurement of fetal middle cerebral artery peak systolic velocity (MCA PSV) for diagnosis of fetal anemia. [fetalmedicine.org]

  Dyserythropoietic Anemia, Congenital A familial disorder characterized by anemia with multinuclear erythroblasts, karyorrhexis, asynchrony of nuclear and cytoplasmic maturation, and various nuclear abnormalities of bone marrow erythrocyte precursors. [healthdictionary.info]

  Hemolytic anemia and benign pelvic tumors. A case report. J Reprod Med. 2001 Apr. 46(4):401-4. [Medline]. Kim I, Lee JY, Kwon JH, et al. A case of autoimmune hemolytic anemia associated with an ovarian teratoma. [emedicine.medscape.com]

  The most common clinical symptoms are pressure, pelvic pain, and irregular bleed, but sometimes it may result from complications such as torsion, rupture, peritonitis, and autoimmune hemolytic anemia [4]. [kamj.eg.net]

• Fatigue

  Contact the American Cancer Society -- www.cancer.org Symptoms Symptoms may include: Chest pain or pressure Cough Fatigue Limited ability to tolerate exercise Shortness of breath Treatment Chemotherapy is used to treat the tumor. [account.allinahealth.org]

  Blood cancers are often associated with this tumor, including: Acute myelogenous leukemia (AML) Myelodysplactic syndromes (group of bone marrow disorders) Symptoms may include: Chest pain or pressure Cough Fatigue Limited ability to tolerate exercise [medlineplus.gov]

  […] are often associated with these tumors, including: Acute myelogenous leukemia (AML) Embryonal rhabdomyosarcoma Malignant histiocytosis Myelodysplasia (MDS) Small cell undifferentiated carcinoma Symptoms Symptoms include: Chest pain or pressure Cough Fatigue [nicklauschildrens.org]

  Blood cancers are often associated with this tumor, including: Acute myelogenous leukemia (AML) Myelodysplactic syndromes (group of bone marrow disorders) Symptoms Symptoms may include: Chest pain or pressure Cough Fatigue Limited ability to tolerate [ufhealth.org]

• Abdominal Pain

  The present case was a 43-year-old female patient and her clinical presentation was abdominal pain, abdominal distension, and abdominal mass sensation. The patient underwent ultrasonography. [ncbi.nlm.nih.gov]

  The current case report presents a 42-year-old female who was admitted to the Emergency Department at Meir Medical Center, Kfar Saba, Israel with abdominal pain. [austinpublishinggroup.com]

• Abdominal Distension

  The present case was a 43-year-old female patient and her clinical presentation was abdominal pain, abdominal distension, and abdominal mass sensation. The patient underwent ultrasonography. [ncbi.nlm.nih.gov]

  Abdominal exam showed distension with large midline mass. There was no tenderness or guarding. [academic.oup.com]

  It occurred in an 8-week-old Korean boy who had been born by cesarean section due to abdominal distension. [doi.org]

  Case report A six-month-old baby girl was admitted in the department of paediatric surgery of Hassan II university hospital in Morocco, with the complaints of abdominal distension and pain since one month. [diagnosticpathology.biomedcentral.com]

• Lower Abdominal Pain

  Twelve years earlier, she had consulted a pediatrician for complaints of lower abdominal pain. [hindawi.com]

  abdominal pain, in 70% of cases accompanied by nausea and vomiting.[6] Pathophysiology[edit] The development of an ovarian mass is related to the development of torsion. [en.wikipedia.org]

  After 8 hours of close observation patient started complaining of insidious lower abdominal pain that increased gradually in intensity and by the time became diffuse on all over the abdomen, on examination the abdomen was firm with diffuse tenderness [jusurgery.com]

  At the age of 16 years, she experienced lower abdominal pain for 2 weeks. [bmcwomenshealth.biomedcentral.com]

  She recently developed sharp lower abdominal pain and abnormal uterine bleeding. [ecancer.org]

• Acute Abdomen

  Mair, Colic from Alternative Systems, The Equine Acute Abdomen, (831-842), (2017). C. E. Sherlock, K. Lott‐Ellis, A. Bergren, J. M. Withers, D. Fews and T. S. [doi.org]

  They may remain asymptomatic or may present with acute abdomen because of torsion, infection, or rupture. Spontaneous rupture of the teratoma is rare and has been occasionally reported. [hindawi.com]

  Retroperitoneal teratoma presenting as acute abdomen in an elderly person. Indian J Gastroenterol. 2000;19:89-90. [ Links ] 11. Pinson C, ReMine SG, Fletcher WS, Braasch JW. Long-term Results With Primary Retroperitoneal Tumors. [scielo.br]

  In the second, the patient presented with signs and symptoms consistent with acute abdomen and had a positive FAST exam. The ruptured MCT was discovered intra-operatively. [jusurgery.com]

• Hypersalivation

  […] was similar to our case [ 9 ], particularly with regard to the memory impairment, psychiatric symptoms and behavioral changes, and also included psychosis, abnormal movements of the face, mouth and tongue, fever, headache, hallucinations, rhinorrhea, hypersalivation [ojrd.biomedcentral.com]

• Hypotension

  BJR was diagnosed on the basis of the severe bradycardia and hypotension observed during the induction of general anesthesia, INTERVENTIONS:: Atropine failed to increase heart rate. [ncbi.nlm.nih.gov]

  […] from other forms of idiopathic orthostatic hypotension (HYPOTENSION, ORTHOSTATIC). [healthdictionary.info]

  In the first case, laparotomy was done because the patient became hypotensive shortly after arrival at the ED. A CT scan performed upon arrival had demonstrated ruptured MCT. [jusurgery.com]

  The patient’s symptoms progressed rapidly - her seizures became intractable and resulted in bradycardia, apnea and hypotension. She was sedated and orotraheal intubated. Serum and CSF tests for NMDAR antibodies were positive. [medichub.ro]

• Liver Mass

  We present the case of a term 3.7 kg neonate who was found to have a giant liver mass at birth, later determined to be an immature teratoma arising from the hepatoduodenal ligament. [ncbi.nlm.nih.gov]

• Flank Pain

  Patients presented most frequently with abdominal or flank pain (63.6%). Median tumor diameter was 9.0 cm and tumors were frequently left-sided (81.8%), cystic (63.6%), and calcified (72.7%) on either radiologic or pathologic examination. [ncbi.nlm.nih.gov]

  These tumors are usually asymptomatic but may manifest as abdominal/back/flank pain, abdominal distention, or a palpable abdominal mass, like in our case. [turkjpath.org]

  The diagnostic algorithm was palpation of a solid flank mass, in our case it was a pelvic mass, plain X-ray to demonstrate calcification or formed bony components like teeth and phalanges which are pathognomonic. [diagnosticpathology.biomedcentral.com]

• Cognitive Disorder

  disorders, autonomic dysfunction, and sleep difficulties. [ncbi.nlm.nih.gov]

Diagnosis of teratomas is made primarily by the presence of a mass or tumor containing bone or other tissue fragments through imaging studies and elevated serum tumor markers.

Imaging studies

• Ultrasound (US) with Doppler is the usual method of initial diagnosis. They can identify the location, content and possible hemodynamics of the tumor [8]. 
• Magnetic resonance imaging (MRI) may be even more accurate for assessment of the tumor [8]. 
• (18F) Fluorodeoxyglucose Positron Emission Tomography (PET) scans provide additional information to detect residual germ cell or mass [16].

The presence of calcification or bony structures within any mass is diagnostic of teratomas, but are only present in a minority of cases [10].

Laboratory studies

Elevated serum levels of (AFP) and b-human chorionic gonadotropin (b-HCG) occur in patients with malignant germ cell tumors [14].

In immature teratomas, AFP serum levels are elevated in 30–60% of patients, but not all. It is, therefore, not a reliable diagnostic tool. AFP serum levels may also be elevated in patients with mature teratomas but are weaker [14].

Levels of a-fetoprotein AFP may return to and remain normal even when the tumor has recurred [15].

Biopsy/histologic examination of resected tumor

Teratomas, regardless of site, have a similar gross appearance and are well circumscribed [3]. Cross sections, shows diverse tissue types. Two or more embryonic germ layers are present in 90% of cases [3]. Mature teratomas are more frequently fluid filled, entirely or partially [3].

• Mediastinal Mass

  A chest X-ray revealed a mediastinal mass, and repeated echocardiography indicated the presence of a large mediastinal mass compressing his main pulmonary artery. [ncbi.nlm.nih.gov]

  Approaching the patient with an anterior mediastinal mass: a guide for clinicians. J Thorac Oncol. 2014;9:S102-9. 2. Carter BW, Okumura M, Detterbeck FC, Marom EM. Approaching the patient with an anterior mediastinal mass: a guide for radiologists. [cancernetwork.com]

  They account for approximately 15% of anterior mediastinal masses in adults and approximately 25% of anterior mediastinal masses in children. They are by far the most common mediastinal germ cell tumor, accounting for 50-70% of such tumors 9. [radiopaedia.org]

The treatment of patients with teratomas should be based on the histology of the tumor. Standard treatment for primary teratoma is complete surgical resection. There are, however, currently no standards for adjuvant therapy [4] [9]. Teratomas, especially those with malignant transformation, are usually resistant to chemotherapy [4].

Surgery

The treatment of choice for all teratomas is complete surgical resection [3] [10]. However, removal of all germ cell material is difficult and results in the high rate of recurrence. The most powerful predictor of patient outcome is the completeness of resection [1] [10].

Minimally invasive antenatal surgical procedures for fetal teratomas may improve outcomes, prevent intrauterine death and preterm delivery [1].

Radiotherapy

This procedure is often used following surgical resection for malignant teratomas or teratomas with the potential of becoming malignant. It is used either alone or in conjunction with chemotherapy.

Chemotherapy

For malignant teratomas surgery is usually followed by chemotherapy. Recent studies report that chemotherapy in conjunction with radiotherapy may increase the duration and rate of survival in patients with immature teratoma [1] [9]. Cisplatin/carboplatin-based drugs have proven to be the most effective chemotherapy medications for these tumors [9]. Cisplatinum therapy results in long-term remissions in approximately 80% of patients with teratomas [7] [16]. Teratomas that are not accessible surgically, are complex, or likely to be malignant may be treated with chemotherapy first.

Follow-up

Although often described as benign, teratomas do have the potential to become malignant and the recurrence rate even in mature teratomas is as high as 40% [16]. Follow-up examinations should be performed frequently by measuring the tumor markers, AFP and b-HCG [10] repeated imaging to detect recurrence [10]. Teratomas may result in significant morbidity, either due to the malignancy or as a result of the surgery, radiation, or chemotherapy [8]. Careful long-term follow-up is necessary for early identification and treatment of complications [8]. With microscopically complete tumor resection, adjuvant chemotherapy or radiotherapy is not required [10] [15]. The difficulty lies in determining absolutely that there are no residual tumor cells remaining. 

Prognosis is good for primary, benign teratomas with complete resection approximately 92-100% [1] [4] [15]. Patients with mature teratoma with germinoma have a 5-year survival rate of 68% [9] [12]. The poor prognosis in teratomas, can be attributed to the high rate of recurrence. The addition of chemotherapy has improved prognosis [9].

Histology and primary site have a significant impact on survival rates for patients with malignant germ cell tumors [15]. Treatment recommendations should be based on the histologic type. In patients with mature teratoma complete surgical resection produce excellent results. Resection and radiotherapy have been used as well [9].

Several recent studies show that chemotherapy may improve the overall duration and rate of survival when used in conjunction with radiotherapy as [12]. Cisplatin/carboplatin-based chemotherapy is the drug of choice.

Complete clinical remission is defined as normal levels found residual tumors in up to 40% of patients even when tumor markers return to normal. Most relapses occur within two to five years of diagnosis [12]. More than 90% of relapses occur at the site of the original tumor[8].

Fetal teratomas result in perinatal mortality of 25% to 37% [7]. In fetuses with fast growing, solid and vascularized teratomas the mortality rate is even higher. These lesions cause cardiac failure due the increased vascular needs of the tumor.

Several variables have been identified that pin point patients at high-risk for disease recurrence. These include primary tumor of the mediastinum, increased tumor burden, and immature teratoma histology [15].

The word teratoma comes from the Greek "teratos" meaning monster and denotes the tortuous or malformed appearance of the tumor [3].

Teratomas are divided into three subgroups according to the extent of differentiation in the tumor cells. The three types are mature teratomas, immature teratomas, and mixed or teratoma with malignant transformation [9].

Teratomas are derived from embryonic germ cells and are present at birth [2], though often not found until adulthood. The peak incidence is 20 to 30 years of age [9]. Retroperitoneal teratomas tend to occur in early childhood and are rarely seen in adults [1].

The overall incidence of teratoma is estimated to be 0.9 per 100,000 in children [5]. Approximately 2.9% of all malignant tumors in children are malignant germ-cell tumors [10].

The incidence of teratoma is higher in females, but the risk of malignant teratoma is higher in males [10].

The distribution of teratomas is reported as 26% in the sacrococcygeal region, 24% in ovaries, 18% in testes and 18% in the brain [10] [11].

Mature, benign teratomas are the most frequent form, accounting for approximately 54.5 %. Immature malignant teratomas account for about 45.5 %.

Teratomas are not well understood. The pathophysiology of teratomas depends on several factors, patient age at diagnosis, sex, tumor site, and cell histology, which result in different cytogenetic and molecular abnormalities [11]. Teratomas originate from two or more germ cell layers (endoderm, ectoderm, or mesoderm) and may be histologically diverse [12]. Teratomas are thought to arise from primordial germ cells. These cells undergo physiologic alterations that change their gametogenesis in the developing gonad [13] [3] [6]. Teratomas are thought to be present at birth (congenital), but small ones are often not discovered until much later in life.

There are three histologic variations of teratoma: mature, benign teratomas, immature, malignant teratomas, and mature teratoma with germinoma [12].

Mature teratomas are benign. They do not infiltrate adjacent organs and can be resected completely. These tumors are often cystic lined with mature squamous epithelium [14]. Their walls may contain various tissues, cartilage, bone, nerve tissues or organ tissue [12] [14]. Mature teratomas with germinoma can grow extensively, recur, and, in some cases, transform into malignancies [12].

Immature teratomas are usually malignant and can metastasize and recur. They are usually solid masses and contain various tissues [6] [12].

Teratomas are also classified according to the Gonzalez-Crussi [6] grading system, a cancer staging system. Teratomas are classified as: 0 - mature (benign); 1- immature, probably benign; 2 - immature, possibly malignant (cancerous); or 3 - frankly malignant [9].

Teratomas are also classified by their content: solid teratomas contain only tissue; cystic teratomas contain only fluid; mixed teratomas containing both solid and cystic components.

Teratomas have their origin in totipotential cells, normally present in the ovary and testes [8], as a result certain hormones are often elevated when teratomas are present. These can be used as tumor markers and include serum α-fetoprotein (AFP), β-human chorionic gonadotropin (β-hCG), CA-125, and CA15-3 [1].

There is currently no way to prevent the occurrence of teratomas, as their cause is not understood. The impact, morbidity, and mortality associated with the disorder may be decreased by early identification and treatment of the tumors.

Routine fetal screening programs, fetal ultrasound with Doppler and magnetic resonance imaging, allow for prenatal diagnosis of some forms of teratoma [8]. They may go a long way to avoid intrauterine fetal death and serious fetal and maternal complications [11].

Teratomas are rare congenital tumors consisting germ cell components of various tissue types. They often contain all three dermal layers: ectoderm, endoderm and mesoderm [1] [2], as well as bone, and organs [3] [4]. Teratomas are present at birth, but are often not discovered until much later [4] [5].

Most teratomas are benign, but they can be innately malignant or have the potential to transform to a malignant form [5]. Even benign teratomas grow aggressively and extend into the surrounding tissue causing damage to the nearby organs and tissue obstructing blood flow [6] [7].

Teratomas can present at any age, including during the fetal and newborn periods resulting in fetal or neonatal death, premature birth, and maternal problems [8].

Malignant teratomas are often resistant to radiotherapy and chemotherapy. The only consistently effective treatment is complete tumor resection. Recurrence is common occurring in 40% of cases.

What are teratomas?

Teratomas are a rare form of tumor which contain embryonic germ cells, cells with the ability to become other tissues. They may contain all three dermal layers, bone, or components of other organs. Teratomas are congenital, present at birth, and are often diagnosed in the fetus or newborn. There are three types of teratoma: mature teratomas which are benign, immature teratomas which are cancerous, and mature teratomas with the ability to transform into the malignant form.

What are the symptoms of teratomas?

The symptoms of teratomas depend on the location, size, and degree they invade surrounding tissue and organs. Symptoms include:

• Pain
• Mass or tumor
• Swelling
• Obstructed blood flow

What causes teratomas?

The cause of teratomas is not known. They are thought to be the result the abnormal development of embryonic germ cells.

Who develops teratomas?

Teratomas can occur in anyone. Peak age at diagnosis is 20 – 30 years of age. They are more common in females than males. Incidence is not affected by race or ethnicity.

How are teratomas diagnosed?

There are two ways of diagnosing teratomas:

• Imaging - X-ray, ultrasound with Doppler, magnetic resonance imaging (MRI), or Positron Emission Tomography (PET).
• Blood work for two fetal hormones that are tumor markers.

How are teratomas treated?

All types of teratomas are treated first by complete surgical removal of the tumor. This may be all that is needed for mature, benign teratomas. Mature teratomas with the potential for becoming malignant may benefit from the addition of radiotherapy after surgery. Immature, malignant, teratomas are usually treated with radiotherapy and chemotherapy.

What are the complications of teratomas?

Teratomas recur in approximately 40% of patients.
Complications of teratomas are related to the effects of the treatment: surgical intervention, radiotherapy, and chemotherapy. Other complications may result from the invasion into the surrounding tissue and organs, and obstruction of blood flow caused by the tumor itself.

What can we do to prevent the complications of teratomas?

The recurrence and complications of teratomas can be prevented by early detection and treatment of the tumors and frequent follow-up.

1. Chu P-Y, Teng T-H, Lee C-C, Chou Y-Y. Adenocarcinomas arising from primary retroperitoneal teratoma in an adult female patient. International Journal of Urology. 2006; 13: 1352–1354.
2. Van Mieghem T, Al-Ibrahim A, Deprest J, Lewi L, Langer LC, Baud D, et al. Minimally invasive therapy for fetal sacrococcygeal teratoma: case series and systematic review of the literature. Ultrasound Obstet Gynecol 2014; 43: 611–619
3. Tapper D, Lack EE. Teratomas in Infancy and Childhood :A 54-Year Experience at the Children's Hospital Medical Center. Ann. Surg. 1983; 198(3):398-410.
4. Chu P-Y, Teng T-H, Lee C-C, Chou Y-Y. Adenocarcinomas arising from primary retroperitoneal teratoma in an adult female patient. International Journal of Urology (2006) 13, 1352–1354
5. Lee HM, Song SY, Park JO, Kim B-H. Primary immature teratoma of the prostate with angiosarcoma component: Its unusual response to chemotherapy. International Journal of Urology (2006) 13, 305–307.
6. Elw N, Porcu P, Loehrer PJ. Sacrococcygeal Teratoma in Adults Case Reports and a Review of the Literature. Cancer. 1999;86(7): 1198-2003.
7. Mieghem TV, Al-Ibrahim A, Deprest J, Lewi L, Langer JC, Baud D, et al. Minimally invasive therapy for fetal sacrococcygeal teratoma: case series and systematic review of the literature. Ultrasound Obstet Gynecol. 2014; 43: 611–619.
8. Gucciardo L, Uyttebroek A, DeWever I, Renard M, Claus F, Devlieger R, et al. Prenatal assessment and management of sacrococcygeal teratoma. Prenat Diagn 2011; 31: 678–688.
9. Ogawa K, Toita T, NakamuraK , Uno T, Onishi H, Itami J, Shikama N, Saeki N, et al. Treatment and Prognosis of Patients with Intracranial Nongerminomatous Malignant Germ Cell Tumors. Cancer. 2003; 98(2): 369-78.
10. Gobel U, Schneider DT, Calaminus G, Haas RJ, Schmidt P, Harms D. Germ-cell tumors in childhood and adolescence. Annals of Oncology. 2000;11: 263-271.
11. Harms D, Zahn S, Göbel U, Schneider DT. Pathology and molecular biology of teratomas in childhood and adolescence. Klinische Pädiatrie 2006 218 (6): 296–302
12. Eggener SE. The Clinical Diversity of Postchemotherapy Germ Cell Teratoma. Cancer. March 15, 2009:1138-42.
13. Furukawa S, Haruta M, Arai Y, Honda S, Ohshima J, Sugawara W, et alYolk sac tumor but not seminoma or teratoma is associated with bnormal epigenetic reprogramming pathway and shows frequent hypermethylation of various tumor suppressor genes. Cancer Sci | April 2009 100 4 698–708.
14. Hiroshima K, Toyozaki T, Iyoda A, Yusa T, Fujisawa T, Ohwada H. Apoptosis and Proliferative Activity in Mature and Immature Teratomas of the Mediastinum. Cancer. 2001;92 (7): 1798-1807.
15. Svatek RS, Spiess PE, Sundi D, Tu S, Tannir NM, Brown GA, Kamat AM, et al. Long-Term Outcome for Men WithTeratoma Found at Postchemotherapy Retroperitoneal Lymph Node Dissection. Cancer. 2009;115:1310-17.
16. Kollmannsberger C, Oechsle K, Dohmen BM, Pfannenberg A, Bares R, Claussen CD, et al. Prospective Comparison of [18F]Fluorodeoxyglucose Positron Emission Tomography with Conventional Assessment by Computed Tomography Scans and Serum Tumor Markers for the Evaluation of Residual Masses in Patients with Nonseminomatous Germ Cell Carcinoma. Cancer. 2002;94(9):2353-63.