What are the other Names for this condition? (Also known as/Symptoms)

• Teratoma of Chest Cavity
• Teratoma of Mediastinum

What is Mediastinal Teratoma? (Definition/Background Information)

• Mediastinal Teratoma is an uncommon form of tumor that arises from the germ cells in the chest cavity or mediastinum. The tumor is observed in young children and young adults
• Most teratoma tumors are either mature or immature. A majority of benign teratomas are mature, while a majority of malignant teratomas are immature
• The cause of formation of Mediastinal Teratoma is unknown. Also, presently, the risk factors for the same are not well-established
• The signs and symptoms of Mediastinal Teratoma depend on the size and nature of the tumor (if benign or malignant). Some tumors may grow to large sizes and cause symptoms such as chest pain, coughing, and other obstructive symptoms. Also, malignant tumors may metastasize to distant organs
• The treatment of teratoma involves surgery in most cases. The successful surgical removal of the tumor is an important prognostic indicator. Malignant Mediastinal Teratomas may be additionally treated using chemotherapy and/or radiation therapy
• In a majority of cases, the prognosis of benign teratoma is excellent with early appropriate treatment. However, the prognosis of malignant teratoma depends upon several factors and can be only assessed on a case-by-case basis

Who gets Mediastinal Teratoma? (Age and Sex Distribution)

• Approximately 24% and 15% of all primary teratomas in children and adults respectively are believed to be Mediastinal Teratomas, which are the most commonly observed germ cell tumors of the mediastinum (in 50-70% of the cases)
• The tumor is mostly diagnosed in infant children before the age of 12 months; or, in young adults (age 20-40 years)
• Both males and females are affected; although, immature teratomas are almost only observed in males
• No specific racial or ethnic group predilection is noted

What are the Risk Factors for Mediastinal Teratoma? (Predisposing Factors)

• Currently, no definite risk factors have been identified for Mediastinal Teratomas
• However, in some cases, the following associations have been noted:
  • Mature teratomas have been associated with Klinefelter syndrome
  • Immature teratomas have been associated with non-lymphocytic leukemia and pleomorphic undifferentiated sarcoma

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Mediastinal Teratoma? (Etiology)

The cause of development of Mediastinal Teratoma is generally unknown. It is believed that abnormal differentiation of germ cells gives rise to the formation of this tumor.

• In general, it is known that cancers form when normal, healthy cells begin transforming into abnormal cells - these cancer cells grow and divide uncontrollably (and lose their ability to die), resulting in the formation of a mass or a tumor
• The transformation of normally healthy cells into cancerous cells may be the result of genetic mutations. Mutations allow the cancer cells to grow and multiply uncontrollably to form new cancer cells
• These tumors can invade nearby tissues and adjoining body organs, and even metastasize and spread to other regions of the body

What are the Signs and Symptoms of Mediastinal Teratoma?

The signs and symptoms of Mediastinal Teratoma depend on subtype of the tumor (whether mature/immature and whether benign/malignant). It may vary from one individual to another. In general, small tumors may be asymptomatic and large tumors can cause signs and symptoms due to mass effect that may include the following:

• Presence of a well-circumscribed typically solitary tumor in the chest cavity
• The tumors may range in size from a few cm to over 25 cm; they may be solid or cystic in nature
• Large tumors (size over 4 cm) can compress the surrounding structures or organs and give the sensation of a chest cavity mass
• Chest pain and cough; blood in cough
• Difficulty breathing or dyspnea
• Large tumors can cause other obstructive signs and symptoms
• When metastasis is noted, it may result in weight loss, fatigue, and other systemic symptoms

How is Mediastinal Teratoma Diagnosed?

There are a variety of tests the healthcare provider may employ to diagnose Mediastinal Teratoma, which may include:

• Physical examination and complete medical history screening
• Assessment of the symptoms observed
• Blood tests for various markers
• Alpha fetoprotein (AFP) blood test
• Plain X-ray of the chest
• CT or CAT scan with contrast of the chest may show a well-defined mass. This radiological procedure creates detailed 3-dimensional images of structures inside the body
• MRI scans of the lungs: Magnetic resonance imaging (MRI) uses a magnetic field to create high-quality pictures of certain parts of the body, such as tissues, muscles, nerves, and bones. These high-quality pictures may reveal the presence of the tumor
• Prenatal diagnostic tests, if necessary

Invasive diagnostic procedures such as:

• Laparoscopy: A special device is inserted through a small hole into the chest region, to visually examine it. If necessary, a tissue sample is obtained for further analysis. Exploration of the abdomen using a laparoscope is called ‘exploratory laparoscopy’
• Laparotomy: The chest is opened through an incision for examination, and if required, a biopsy sample obtained. Exploration of the chest using laparotomy procedure is called ‘exploratory laparotomy’

Although the above modalities can be used to make an initial diagnosis, a tissue biopsy of the tumor is necessary to make a definitive diagnosis to begin treatment. The tissue for diagnosis can be procured in multiple different ways which include:

• Fine needle aspiration (FNA) biopsy of the tumor: A FNA biopsy may not be helpful, because one may not be able to visualize the different morphological areas of the tumor. Hence, a FNA biopsy as a diagnostic tool has certain limitations, and an open surgical biopsy is preferred. Also, Solitary Fibrous Tumor is a fibrous tumor and FNA usually does not reveal many cells on microscopic examination
• Core biopsy of the tumor
• Open biopsy of the tumor

Tissue biopsy from the affected region:

• A biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
• Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
• Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, flow cytometric analysis and very rarely, electron microscopic studies, to assist in the diagnosis

Note: A differential diagnosis to eliminate other tumor types may be necessary prior to establishing a definite diagnosis.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Mediastinal Teratoma?

The complications of Mediastinal Teratoma may depend on the size of the tumor and the region of the body affected. It also depends on whether the tumor is benign or malignant. The complications may include the following:

• Stress and anxiety due to fear of mediastinal cancer
• Respiratory distress in infants and young children
• Large tumor masses may get secondarily infected with bacteria or fungus
• Organ dysfunction that may occur from large tumors; large tumors may compress the lungs, heart, and major blood vessels
• Fluid in the lungs (pleural effusion); pneumothorax due to air in the pleural region
• Fluid surrounding the heart (pericardial effusion); cardiac tamponade
• Some immature teratomas are known to rupture and cause associated complications
• Metastasis of malignant teratoma to distant sites
• Recurrence of the tumor following its incomplete surgical removal: Immature forms are more often likely to recur than mature forms
• Some mature teratomas are known to transform to malignant teratomas, which are most commonly carcinomas, sarcomas, or adenocarcinomas

There may be complications related to the methods used in treating the condition and may include:

• Side effects of radiation therapy that may include sunburn-like rashes, where radiation was targeted, red or dry skin, heaviness of the breasts, and general fatigue
• Side effects of chemotherapy, which may include nausea, vomiting, hair loss, decreased appetite, mouth sores, fatigue, low blood cell counts, and a higher chance of developing infections
• The treatment can also cause infertility in men and women. Hence, measures to protect the individual’s fertility must be considered, before starting chemotherapy
• Damage to the muscles, vital nerves, and blood vessels, during surgery
• Post-surgical infection at the wound site is a potential complication

How is Mediastinal Teratoma Treated?

The treatment of Mediastinal Teratoma may involve the following:

• Generally, the treatment of choice is complete surgical excision for all Mediastinal Teratomas
• However, while it is usually possible to surgically remove a benign teratoma, the complete removal of a malignant teratoma may be challenging, if local infiltration of the tumor is noted
• Chemotherapy and/or radiation therapy may be necessary for malignant teratomas
• Follow-up care with regular screening and check-ups are important and encouraged

How can Mediastinal Teratoma be Prevented?

Currently, there are no known methods to prevent the development of Mediastinal Teratoma.

What is the Prognosis of Mediastinal Teratoma? (Outcomes/Resolutions)

• The prognosis of Mediastinal Teratoma depends upon whether it is a mature or immature type (also, whether the tumor is benign or malignant)
  • Many of the tumors are mature teratomas that behave in a benign manner. With complete surgical removal of the tumor, the prognosis is typically excellent
  • Immature teratomas may be aggressive, difficult to treat (complete tumor resection may not be possible), and can spread to other sites. The prognosis of these tumors is usually assessed on a case-by-case basis
  • The prognosis of children is generally better than the prognosis in adults
• If immature teratomas can be completely removed through surgery, then the prognosis is generally improved

Additional and Relevant Useful Information for Mediastinal Teratoma:

The following article link will help you understand other cancers and benign tumors:

http://www.dovemed.com/diseases-conditions/cancer/