Teratoma

Teratomas are a type of germ-cell tumoura tissue mass that forms from groups of unhealthy cells that contains different types of bodily tissuea group of cells that work together to perform a function, such as hair, bone, muscle and teeth. They contain elements from three embryonic germ layers; the endoderm (the innermost layer that forms the respiratory and gastrointestinal tracts), the mesoderm (the middle layer that forms the circulatory and lymphatic systema network of tissues and organs that help our bodies fight infection and disease, bone, cartilage, muscles and various organs) and the ectoderm (the outermost layer that forms the nervous system, skin, and sensory organs such as the eyes, ears and nose).

Germ cell tumours are a rare group of neoplasms that arise from primordial germ cellsa cell that develops into reproductive cells (eggs in females, sperm in males) – the cellsthe basic structural and functional unit of all living things responsible for developing into reproductive cells (gametes) such as ovum and sperm. These tumours typically originate in the gonads, which are the organs that produce gametes (ovaries in females and the testicles in males). These tumours are referred to as gonadal germ cell tumours. In some cases, germ cells can migrate to other parts of the body during early embryonic development, leading to tumour formation outside of the gonads later in life. These are known as extragonadal germ cell tumours, and are most commonly found in the brain, mediastinumthe space between the lungs that holds many important structures, including the heart, trachea and oesophagus, retroperitoneuma space located behind the abdomen that contains many important bodily structures, such as the kidneys, or sacrococcygeal region.

Teratomas are broadly classified into three different categories: mature teratomas, immature teratomas and teratomas with somatic type malignancy. Mature teratomas are generally benignnot cancerous, can grow but will not spread to other body parts, and contain cells that look similar to healthy tissue but contain bodily tissue that shouldn’t be present within the brain (such as skin, hair, muscle, bone, etc.). Immature teratomas can be malignantcancerous, may grow and spread to other areas of the body, and contain cells that cells look similar to those found in a fetus, while also containing components not generally found in the brain. Teratomas with somatic type malignancy are malignant, and occur when a teratoma develops a non-germ cell component, such as a sarcomacancer arising from bones and/or soft tissue.

Teratomas are more common in females, with the average age at presentation varying by subtype. However, anyone can develop this disease.

Types of Teratomas

Teratomas can be classified by their location within the body.

Gonadal Teratomas

Gonadal teratomas are more common, and develop in either the ovaries or testicles.

Ovarian Teratomas

Ovarian teratomas are a common type of germ-cell tumour that generally affects females in the reproductive age range. Most of these tumours are mature, benign, and discovered incidentally. Immature ovarian teratomas are less common, and tend to affect females under 20 years old. Immature ovarian teratomas can be malignant, but can have a good prognosisto predict how a disease/condition may progress and what the outcome might be when caught early.

Testicular Teratomas

Testicular teratomas are a type of germ-cell tumour that occur most often in males under the age of 40. In prepubertal males, teratomas are usually benign and composed of mature tissues. However, in post pubertal males, testicular teratomas are considered malignant regardless of histological maturity due to their potential for local invasion and metastasiswhen the cancer has spread to other parts of the body, also known as mets. While malignant testicular teratomas can be aggressive, they can have a good prognosis when found early.

Extragonadal Teratomas

Extragonadal teratomas are much less common than gonadal teratomas, and develop in areas other than the gonads.

Mediastinal Teratomas

Mediastinal teratomas are the most common type of extra-gonadal germ-cell tumour that develops in the mediastinum, most commonly the anterior mediastinum. Mature mediastinal teratomas are generally diagnosed between the ages of 20-40, often found incidentally, and tend to be benign and slow growing. Immature teratomas are more likely to occur in infants and children, and are almost always found in males. When immature teratomas are malignant, they can be aggressive, but can have a good prognosis when found early.

Sacrococcygeal Teratomas

Sacrococcygeal teratomas are the most common type of germ-cell tumours in fetuses, newborns and infants. These tumours arise at the base of the spine in an area known as the sacrococcygeal region. Most sacrococcygeal teratomas are mature and benign, especially when diagnosed in the neonatal period, and may be detected during pregnancy on an ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body or present as a visible massa growth of cells that come together to make a lump, may or may not be cancer at birth. Immature sacrococcygeal teratomas are less common, tend to occur in older infants and children, and have a higher riskthe possibility that something bad will happen of malignancy.

Sacrococcygeal teratomas can also be classified based on location:

Type I: the most common subtype; tumour develops almost completely outside of the body.

Type II: tumour develops outside of the body but extends into the pelvis.

Type III: tumour develops outside of the body, but extends through the pelvis and into the abdomenstomach, stomach area, belly.
Type IV: tumour develops entirely inside the pelvis.

Sacrococcygeal teratomas can have a good prognosis when found early.

Rare types of Teratoma

These types of teratoma are considered to be very rare:

Congenital cervical teratoma.

Intracranial teratoma.

Retroperitoneal teratoma.
Spinal cord teratoma.

Treatment

If a teratoma is detected, it will be staged and graded based on size, metastasis, and how the cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading help your doctors determine the best treatment for you.

FIGO Staging System – Ovarian Teratomas

Ovarian cancers can be staged using the Federation of Gynaecologythe study of the female reproductive system and related diseases and Obstetrics (FIGO) system from stage I to IV:

Stage I: cancer cells are confined to one or both ovaries only. This stage is also known as early-stage cancer.

Stage II: cancer cells have grown deeper into nearby organs in the pelvis, such as the uterus, fallopian tubes, bladder and/or bowelportion of the digestive system that digests food (small bowel) and absorbs salts and water (large bowel); also called intestines. This is also known as localised cancer.

Stage III: the cancer has become larger and has spread beyond the pelvis into the lining of the abdomen (peritoneumthe membrane that lines the abdominal cavity). Lymph nodes are also often affected. This is also known as advanced or metastatic cancer.

Stage IV: the cancer has spread to more distant organs, such as the lungs or the liver. This is also known as advancedat a late stage, far along or metastatic cancer.

TMN Staging System

All other teratomas can be staged using the TNM staging system:

T (tumour) indicates the size and depth of the tumour.

N (nodea small lump or mass of tissue in your body) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.

M (metastasis) indicates whether the cancer has spread to other parts of the body.

This system can also be used in combination with a numerical value, from stage 0-IV:

Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.

Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.

Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localisedaffecting only one area of body cancer.

Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.

Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advanced or metastatic cancer.

Cancers can also be graded based on the rate of growth and how likely they are to spread:

Gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.

Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.

Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.

Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.

Treatment Options

Treatment is dependent on several factors, including location, age, stage of disease and overall health.

Treatment options for teratomas may include:

Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence to remove as much of the tumour as possible – will vary based on tumour location.

Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.

Ablation therapya minimally invasive procedure that uses extremely high or low temperatures to destroy (ablate) abnormal tissue and/or cancer cells.

Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.

Gonadal Teratoma Treatment and Fertility

Treatment for ovarian and testicular teratomas may make it difficult to conceive a child. If fertility is important to you, discuss your options with your doctor and a fertility specialist prior to the commencement of treatment.

Risk factors

Because of how rare teratomas are, there has been limited research done into the risk factors of this disease. However, a link has been found between the development of mediastinal germ cell tumours and males with the genetic disorder Klinefelter syndrome.

Symptoms

The symptoms of embryonal carcinomacancer arising from tissues that line organs will vary based on location.

Symptoms of Ovarian Teratoma

Symptoms of ovarian teratoma may include:

Pelvic pain.

Abdominal pain.

A palpable pelvic mass.
Ovarian torsion (rare).

Symptoms of Testicular Teratoma

Symptoms of testicular teratoma may include:

A painless mass in the testicle(s).

Changes in testicular size and/or shape.

A feeling of heaviness and/or unevenness in the scrotum.

Pain or discomfort in the testicle(s) and/or scrotum (less common).

Symptoms of Mediastinal Teratoma

Symptoms of mediastinal teratoma may include:

Dyspneadifficulty breathing, shortness of breath.

Chest pain.

Persistent cough.

Haemoptysiscoughing up blood.

Superior vena cava syndrome, which has its own set of symptoms:

Coughing.

Dyspnea.

Swelling of the face, neck, and/or upper arms.

Symptoms of Sacrococcygeal Teratoma

Symptoms of sacrococcygeal teratoma may include:

Large mass at the base of the spine.

Kidneya pair of bean-shaped organs in the abdomen that are responsible for filtering excess water and waste products from the blood and converting them into urine to be removed from the body or bladdera hollow, muscular sac in the pelvis that stores urine enlargement or blockage (rare).

Hydrops (accumulation of fluid in a fetuses body, causing swelling).

Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.

Diagnosis

If your doctor suspects you have a teratoma, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:

Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.

Endocrine studiesstudies that involve blood, urine and/or imaging tests to analyse hormone levels.

Blood teststesting done to measure the levels of certain substances in the blood.

Imagingtests that create detailed images of areas inside the body tests, potentially including:

- Ultrasound.

- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.

- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.

- PET (positron emission tomography) scana type of medical imaging that uses radioactive tracers to create detailed images of the body.

- Chest X-raya type of medical imaging that uses x-ray beams to create detailed images of the body (mediastinal teratomas).

Exploratory surgerya surgical procedure used for conditions that cannot be confirmed by scans and tests alone.
Biopsyremoval of a section of tissue to analyse for cancer cells (where possible).

Exploratory Surgery

After conducting the previously mentioned diagnostic tests, your doctor may strongly suspect that you have testicular or ovarian cancer. In most cases, a diagnosis can be confirmed after a biopsy, where a section of tissue is removed and analysed for cancer cells. However, doctors avoid conducting a biopsy in patients who have suspected testicular and ovarian cancer as there is a small risk that making an incision in the scrotum or ovary could cause cancer cells to spread.  As such, the only way to confirm the diagnosis safely is to remove the affected gonad.

Once the gonad has been removed, it will be sent to a laboratory and analysed for cancer cells.