Germ Cell Tumors
What are germ cell tumors?
Germ cells tumors are malignant (cancerous) or non-malignant (benign, non-cancerous) tumors that are comprised mostly of germ cells. Germ cells are the cells that develop in the embryo (fetus, or unborn baby) and become the cells that make up the reproductive system in males and females. These germ cells follow a midline path through the body after development and descend into the pelvis as ovarian cells or into the scrotal sac as testicular cells. Most ovarian tumors and testicular tumors are of germ cell origin. The ovaries and testes are called gonads.
Tumor sites outside the gonad are called extragonadal sites. The tumors also occur along the midline path and can be found in the head, chest, abdomen, pelvis, and sacrococcygeal (lower back) area.
Germ cell tumors can spread (metastasize) to other parts of the body. The most common sites for metastasis are the lungs, liver, lymph nodes, and central nervous system. Rarely, germ cell tumors can spread to the bone, bone marrow, and other organs.
Germ cell tumors are diagnosed in approximately 900 children each year. Germ cell tumors account for 16 percent of all cancers diagnosed in adolescents between the ages of 15 and 19 years of age, and nearly 4 percent of cancers diagnosed in children younger than 15 years of age.
What are the types of germ cell tumors?
Diagnosis of germ cell tumors depends on the types of cells involved. There are several common types of germ cell tumors:
Teratomas contain cells from the three germ layers: ectoderm, mesoderm, and endoderm. Teratomas can be malignant or benign, depending on the maturity and other types of cells that may be involved. Teratomas are the most common germ cell tumor found in the ovaries. Sacrococcygeal (tail bone, or distal end of spinal column) teratomas are the most common germ cell tumors found in childhood. Because these sacrococcygeal tumors are often visible from the outside of the body, diagnosis is made early and treatment and/or surgery are initiated early, making the prognosis for this type of germ cell tumor very favorable.
Germinomas are malignant germ cell tumors. Germinomas are also termed dysgerminoma when located in the ovaries; and seminoma when located in the testes. Among children, germinoma, or dysgerminoma, occurs most frequently in the ovary of a pre-pubescent or adolescent female. Dysgerminoma is the most common malignant ovarian germ cell tumor seen in children and adolescents.
Endodermal sinus tumor or yolk sac tumors are germ cell tumors that are most often malignant, but may also be benign. These tumors are most commonly found in the ovary, testes, and sacrococcygeal areas (tail bone, or distal end of spinal column). When found in the ovaries and testes, they are often very aggressive, malignant, and can spread rapidly through the lymphatic system and other organs in the body. Yolk sac tumors are the most common malignant testicular and ovarian tumors in children. Most yolk sac tumors will require surgery and chemotherapy, regardless of stage or presence of metastasis, because of the aggressive nature and recurrence of the disease.
Choriocarcinoma is a very rare, but often malignant germ cell tumor that arises from the cells in the chorion layer of the placenta (during pregnancy, a blood-rich structure through which the fetus takes in oxygen, food, and other substances while getting rid of waste products). These cells may form a tumor in the placental cells during pregnancy and spread (metastasize) to the infant and mother. When the tumor develops during pregnancy, it is called gestational choriocarcinoma. Gestational choriocarcinoma most often occurs in pregnant females that are 15 to 19 years of age. If a non-pregnant young child develops choriocarcinoma from the chorion cells that originated from the placenta that are still in the body, the term used is non-gestational choriocarcinoma.
Embryonal carcinoma cells are malignant cells that are usually mixed with other types of germ cell tumors. They occur most often in the testes. These types of cells have the ability to spread to other parts of the body. When these cells are mixed with an otherwise benign type of tumor (mature teratoma), the presence of embryonal carcinoma cells will cause it to become malignant (cancerous).
Many germ cell tumors have multiple types of cells involved. The diagnosis, treatment, and prognosis are based on the most malignant of the cells present and the majority type of cells that are present.
What are the causes of germ cell tumors?
The cause of germ cell tumors is not completely understood. A number of inherited defects have also been associated with an increased risk of developing germ cell tumors including the central nervous system and genitourinary tract malformations and major malformations of the lower spine. Specifically, males with cryptorchidism (failure of the testes to descend into the scrotal sac) have an increased risk to develop testicular germ cell tumors. Cryptorchidism can occur alone, however, and is also present in some genetic syndromes.
In addition, cells from testicular germ cell tumors can have structural chromosome abnormalities involving chromosome #12, which may explain the uncontrolled cell growth and tumor formation.
Some genetic syndromes caused by extra or missing sex chromosomes can cause incomplete or abnormal development of the reproductive system.
A tumor, swelling or mass that can be felt or seen, commonly in the abdomen or pelvis.
Wheezing or cough in the tumor is in the chest.
Constipation, incontinence, and leg weakness can occur if the tumor is in the sacrum (a segment of the vertebral column that forms the top part of the pelvis) compressing structures.
Abnormal shape, or irregularity in, testicular size.
Hodgkin Lymphoma
What is Hodgkin lymphoma?
Hodgkin lymphoma is diagnosed in approximately 900 children each year and accounts for nearly 5 percent of childhood cancers. Hodgkin lymphoma occurs most often in people between the ages of 15 and 34, and in people over age 55. The disease, for unknown reasons, affects males more than twice as often as females.
Hodgkin lymphoma is a type of cancer in the lymphatic system. The lymphatic system is part of the immune system and functions to fight disease and infections.
The lymphatic system includes the following: Lymph is fluid containing lymphocyte cells.
Lymph vessels are thin tubes that carry lymph fluid throughout the body.
Lymphocytes are white blood cells that fight infection and disease.
Lymph nodes are bean-shaped organs, found in the underarm, groin, neck, chest, and abdomen, that act as filters for the lymph fluid as it circulates through the body.
Hodgkin lymphoma causes the cells in the lymphatic system to abnormally reproduce, eventually making the body less able to fight infection and cause swelling in the lymph nodes. Hodgkin lymphoma cells can also spread to other organs and tissue. A cancer cell that has spread to other organs and tissue is called metastasis. It is a rare disease, accounting for less than 1 percent of all cases of cancer in the US.
What are the causes of Hodgkin lymphoma?
The specific cause of Hodgkin lymphoma is unknown. It is possible that a genetic predisposition and exposure to viral infections may increase the risk for developing Hodgkin lymphoma. There is a slightly increased chance for Hodgkin lymphoma to occur in siblings and cousins of patients.
There has been much investigation into the association of the Epstein-Barr virus (EBV), which causes the infection mononucleosis, as well as with human immunodeficiency virus (HIV), which causes acquired immune deficiency syndrome (AIDS). Both of these infectious viruses have been correlated with a greater incidence of children diagnosed with Hodgkin lymphoma, although the direct link is unknown.
However, there are many individuals who have infections related to EBV and HIV that do not develop Hodgkin disease.
What are the symptoms of Hodgkin lymphoma?
The following are the most common symptoms of Hodgkin lymphoma. However, each child may experience symptoms differently. Symptoms may include:
Painless swelling of the lymph nodes in neck, underarm, groin, and chest.
Difficulty breathing (dyspnea) due to a enlarged nodes in the chest.
Fever.
Night sweats.
Fatigue (tiring easily).
Weight loss/decreased appetite.
Itching skin (pruritus).
Frequent viral infections (i.e., cold, flu, sinus infection).
The symptoms of Hodgkin lymphoma may resemble other blood disorders or medical problems.
Leukemia
What is leukemia?
Leukemia is the most common form of pediatric cancer. It affects approximately 3,250 children each year in the US, accounting for about 30 percent of childhood cancers. It can occur at any age, although it is most commonly seen in children between 2 and 6 years of age. The disease occurs slightly more frequently in males than in females, and is more commonly seen in Caucasian children than with African-American children, or children of other races.
Leukemia is cancer of the blood and develops in the bone marrow. The bone marrow is the soft, spongy center of the long bones that produces the three major blood cells: white blood cells to fight infection; red blood cells that carry oxygen; and platelets that help with blood clotting and stop bleeding.
When a child has leukemia, the bone marrow, for an unknown reason, begins to make white blood cells that do not mature correctly, but continue to reproduce themselves. Normal, healthy cells only reproduce when there is enough space for them to fit. The body can regulate the production of cells by sending signals when to stop. With leukemia, these cells do not respond to the signals to stop, and reproduce regardless of space available. These abnormal cells reproduce very quickly and do not function as healthy white blood cells to help fight infection.
What are the causes of leukemia in children?
A majority of childhood leukemias are acquired genetic diseases. This means that gene mutations and chromosome abnormalities in cells occur sporadically.
The immune system plays an important role in protecting the body from diseases, and possibly cancer. An alteration or defect in the immune system may increase the risk for developing leukemia. Factors such as exposure to certain viruses, environmental factors, chemical exposures, and various infections have been associated with damage to the immune system. However, with the exception of specific genetic syndromes, little is known about the causes of childhood leukemia.
What are the different types of leukemia?
There are several main types of leukemia in children.
Acute lymphocytic leukemia (ALL)
Acute lymphocytic leukemia (ALL), also called lymphoblastic or lymphoid, accounts for approximately 75 percent of childhood leukemia.
In this form of the disease, the lymphocyte cell line is affected. The lymphocytes normally fight infection. With acute lymphocytic leukemia, the bone marrow makes too many of these lymphocytes and they do not mature correctly. The lymphocytes overproduce and crowd out other blood cells. Immature blood cells (blasts) do not work properly to fight infection. Acute leukemia can occur over a short period of days to weeks. Chromosome abnormalities (extra chromosomes and structural changes in the chromosome material) are present in the majority of the blast cells of ALL patients.
Acute myelogenous leukemia (AML)
Acute myelogenous leukemia (AML), also called granulocytic, myelocytic, myeloblastic, or myeloid, accounts for approximately 19 percent of childhood leukemia.
Acute myelogenous leukemia is a cancer of the blood in which too many granulocytes, a type of white blood cell, are produced in the marrow. The granulocytes normally fight infection. With acute myelogenous leukemia, the bone marrow makes too many of these cells and they do not mature correctly. The granulocytes overproduce and crowd out other blood cells. Immature blood cells (blasts) do not work properly to fight infection. Acute leukemia can occur over a short period of days to weeks. Children with certain genetic syndromes, including Fanconi anemia, Bloom syndrome, Kostmann syndrome, and Down syndrome, are at a higher risk of developing AML than other children.
Chronic myelogenous leukemia (CML)
Chronic myelogenous leukemia (CML) is uncommon in children. Chronic myelogenous leukemia is cancer of the blood in which too many granulocytes, a type of white blood cell, are produced in the marrow. The granulocytes normally fight infection. With this disease, the bone marrow makes too many of these cells and they do not mature correctly. The marrow continues to produce these abnormal cells which crowd out other healthy blood cells.
Chronic myelogenous leukemia can occur over a period of months or years. A specific chromosome rearrangement is found in patients with CML. Part of chromosome #9 breaks off and attaches itself to chromosome #22, so that there is an exchange of genetic material between these two chromosomes. This rearrangement changes the position and functions of certain genes, which results in uncontrolled cell growth. Other chromosome abnormalities can also be present.
What is the difference between the types of leukemia?
The difference between lymphocytic and myelogenous is the stage of development on what is called the pluripotent stem cell. The pluripotent stem cell is the first stage of development of all of the blood cells (white blood cells, red blood cells, and platelets). This stem cell goes through stages of development until it matures into a functioning cell. The type of leukemia is determined by which stage of development a cell is in when it becomes malignant, or cancerous.
The stem cell matures into either the lymphoid or myeloid cells. The lymphoid cells mature into either B-lymphocytes or T-lymphocytes. If the leukemia is among these cells, it is called acute lymphocytic leukemia (ALL). If the leukemia is found even further along in this stage of development, it can be further classified as B-cell ALL or T-cell ALL. The more mature the cell, the more difficult it is to treat.
The myeloid cells develop into platelets, red blood cells, and specialized white blood cells called neutrophils and macrophages. There are many classifications of AML. The type of leukemia is determined by the stage of development when the normal cells become leukemia cells.
What are the symptoms of leukemia?
Because leukemia is cancer of the blood-forming tissue called the bone marrow, the initial symptoms are often related to irregular bone marrow function. The bone marrow is responsible for storing and producing about 95 percent of the body's blood cells, including the red blood cells, white blood cells, and platelets.
When leukemia occurs, the abnormal white blood cells (blasts) begin to reproduce very rapidly and begin crowding out and competing for nutrients and space with the other healthy cells. The following are the most common symptoms of leukemia. However, each child may experience symptoms differently. Symptoms may include:
Anemia is present when red blood cells are unable to be produced because of the crowding in the marrow. With anemia, the child may appear tired, pale, and may breathe faster to compensate for the decrease in oxygen carrying capacity. The number of red blood cells on a blood count (and the hemoglobin) will be below normal.
Bleeding and/or bruising can occur when platelets are unable to be produced because of the crowding in the marrow. Petechiae are tiny red dots often seen on the skin of a child with low number of platelets. Petechiae are very small blood vessels that have leaked or bled. The number of platelets on a blood count will be below normal. Thrombocytopenia is the term used for a decreased number of platelets.
Recurrent infections. Although there may be an unusually high number of white blood cells on a blood count of a child with leukemia, these white blood cells are immature and do not fight infection. The child may have had repetitive viral or bacterial infections over the past few weeks. The child with leukemia often shows symptoms of an infection such as fever, runny nose, and cough.
Bone and joint pain can happen when the bone marrow is overcrowded and “full.”
Abdominal distress happens when leukemia cells collect in the kidney, liver and spleen, causing enlargement of these organs. Abdominal pain may cause a child to have loss of appetite and weight loss.
Swollen lymph nodes under the arms, in the groin, chest, and in the neck happen when leukemia cells collect in the nodes, causing swelling. Lymph nodes are responsible for filtering the blood.
Difficulty breathing (dyspnea). With T-cell ALL, these leukemia cells tend to clump together around the thymus. This mass of cells present in the middle of the chest can cause pain and difficulty breathing (dyspnea). Wheezing, coughing, and/or painful breathing requires immediate medical attention.
With acute leukemia (ALL or AML), these symptoms may occur suddenly in a matter of days or weeks. With chronic leukemia (CML), these symptoms may develop slowly over months to years.
It is important to understand that the symptoms of leukemia may resemble other blood disorders or medical problems. These are common symptoms of the disease, but do not include all possible symptoms. Children may experience symptoms differently. Always consult your child's physician for a diagnosis.
Neuroblastoma
What is neuroblastoma?
Neuroblastoma is one of the most common types of solid tumors found in children and accounts for approximately 7 to 10 percent of all childhood cancers. In the United States, approximately 650 children are diagnosed with neuroblastoma each year. It is often present at birth, but not detected until the tumor begins to grow and compress the surrounding organs. Most children affected by neuroblastoma have been diagnosed before the age of 5. In rare cases, neuroblastoma can be detected before birth by a fetal ultrasound. It is the most common tumor found in children younger than 1 year of age. For unknown reasons, it occurs slightly more often in males than in females.
Neuroblastoma is a cancerous tumor that begins in nerve tissue of infants and very young children. The abnormal cells are often found in the nerve tissue that is present in the unborn baby and later develops into a detectable tumor. Neuroblastoma is rare in children older than 10 years of age; however, it does occur occasionally in adults.
The tumor usually begins in the tissues of the adrenal gland found in the abdomen, but may also begin in nerve tissue in the neck, chest, and/or pelvis. The adrenal glands are positioned on top of the kidneys. These glands secrete hormones and other important substances that are required for normal functions in the body such as the nervous system.
Neuroblastoma cancer cells can spread (metastasize) quickly to other areas of the body (i.e., lymph nodes, liver, lungs, bones, central nervous system, and bone marrow). Approximately 70 percent of all children diagnosed with neuroblastoma will have some metastatic disease.
What are the causes of neuroblastoma?
Most neuroblastoma cells have genetic abnormalities involving chromosome #1 where a deletion or rearrangement is found on the short arm of this chromosome. The chromosome abnormality, in turn, causes amplification of an oncogene called n-myc, even though this gene is not located on chromosome #1. The amplification of n-myc causes uncontrolled cell growth. A variety of other chromosome abnormalities may also be present in neuroblastoma.
As many as 20 percent of neuroblastoma cases are caused by an inherited mutation, followed by a second mutation occurring after birth, which together initiate uncontrolled cell growth. The remainder of the cases occur from two acquired mutations after birth. Because the tumor occurs very early in childhood, it is doubtful that any environmental exposures the child has incurred could be linked to the development of the tumor.
Neuroblastoma is more common in children born with fetal hydantoin syndrome, neurofibromatosis, and Beckwith-Wiedemann syndrome. The exact relationship between these conditions and the disease are not known.
The chance for neuroblastoma to be present in a future sibling of the patient is approximately 1 percent. If more than one child has neuroblastoma, the chance for reoccurrence increases.
Research is being conducted to determine if maternal exposure to any toxic substances, environmental pollutions or radiation during pregnancy could have any link to the child developing neuroblastoma.
What are the symptoms of neuroblastoma?
The following are the most common symptoms of neuroblastoma. However, each child may experience symptoms differently. The symptoms of neuroblastoma vary greatly depending on size, location, and spread of the tumor. Symptoms may include:
Abdominal mass, either felt during an examination or seen as swollen abdomen.
Swelling and bruising around the eyes and uncontrolled eye movement.
Changes in urination caused by the tumor compressing the kidney or bladder.
Pain, limping, paralysis, or weakness from bone marrow involvement.
Diarrhea caused by a substance produced by the tumor (vasoactive intestinal peptide, or VIP).
Fever.
High blood pressure and increased heart rate may occur depending on location of tumor and the organs the tumor compresses.
Weight loss and/or decreased appetite.
Fatigue (feeling tired or weak).
Numbness.
Difficulty walking.
Non-Hodgkin Lymphoma
What is non-Hodgkin lymphoma (NHL)?
Non-Hodgkin lymphoma is cancer in the lymphatic system. Sixty percent of lymphomas are non-Hodgkin lymphomas. The lymphatic system is part of the immune system and functions to fight disease and infections.
The lymphatic system includes the following:
Lymph is fluid containing lymphocyte cells.
Lymph vessels are thin tubes that carry lymph fluid throughout the body.
Lymphocytes are white blood cells that fight infection and disease.
Lymph nodes are bean-shaped organs, found in the underarm, groin, neck, chest, and abdomen, that act as filters for the lymph fluid as it circulates through the body.
Non-Hodgkin lymphoma causes the cells in the lymphatic system to abnormally reproduce, eventually causing tumors to grow. Non-Hodgkin disease cells can also spread to other organs and tissues in the body.
Non-Hodgkin lymphoma is the third most common childhood cancer. About 800 cases of non-Hodgkin lymphoma in children are diagnosed each year. It occurs most often in children between the ages of 7 and 11, but can occur at any age from infancy to adulthood.
Non-Hodgkin lymphoma affects males almost three times more often than females, and is more common among Caucasian children than among African-American children and children of other races.
Staging and classification of non-Hodgkin lymphoma is based on the extent of the disease and the specific cells involved.
What are the different types of non-Hodgkin lymphoma?
There are several subtypes of non-Hodgkin lymphoma.
Lymphoblastic non-Hodgkin lymphoma accounts for approximately 35 percent of the cases, involves the T-cells, and usually presents with a mass in the chest, swollen lymph node(s), with or without bone marrow and central nervous system involvement.
Burkitt or Burkitt-like lymphoma is a non-Hodgkin disease in which the cells are undifferentiated and diffuse. This has also been referred to as small non-cleaved cells. Burkitt and Burkitt-like lymphoma accounts for approximately 40 to 50 percent of non-Hodgkin lymphoma in children and is often characterized by a large abdominal tumor and may have bone marrow and central nervous system involvement.
Diffuse large B cell non-Hodgkin lymphoma accounts for approximately 15 to 20 percent of the cases. Children with this type of non-Hodgkin lymphoma usually have lymphatic system involvement, as well as a non-lymph structure (i.e., lung, jaw, brain, skin, and bone) involvement.
Anaplastic large cell lymphoma is a rare cancer that accounts for approximately 10 percent of non-Hodgkin lymphoma in children. Skin is often involved.
What are the stages of non-Hodgkin lymphoma?
Staging is the process of determining whether cancer has spread and, if so, how far. There are various staging symptoms that are used for non-Hodgkin lymphoma. Always consult a child's physician for information on staging. One method of staging non-Hodgkin lymphoma is the following:
Stage I involves the tumor at one site, either nodal or elsewhere in the body.
Stage II involves the tumor at two or more sites on the same side of the body.
Stage III involves tumors in any number that occur on both sides of the body, but does not involve bone marrow or the central nervous system.
Stage IV is any stage of tumor that also has bone marrow and/or central nervous system involvement.
Stage IV is also subdivided depending on the amount of blasts (cancer cells) present in the bone marrow.
What are the causes of non-Hodgkin lymphoma?
The specific cause of non-Hodgkin lymphoma is unclear. It is possible that genetics and exposure to viral infections may increase the risk for developing this malignancy. Non-Hodgkin lymphoma has also been linked to chemotherapy and radiation therapy and may be a second malignancy, resulting from treatment for certain cancers.
There has been much investigation into the association of the Epstein-Barr virus (EBV) that causes the mononucleosis infection; as well as the human immunodeficiency virus (HIV), which causes acquired immune deficiency syndrome (AIDS). Both of these infectious viruses have been linked to the development of non-Hodgkin lymphoma.
The majority of Burkitt's lymphoma cases result from a chromosome rearrangement between chromosome #8 and #14, which causes genes to change positions and function differently, promoting uncontrolled cell growth. Other chromosome rearrangements have been seen in non-Hodgkin lymphoma (all types) that are also thought to promote excessive cell growth.
Children and adults with other hereditary abnormalities have an increased risk of developing non-Hodgkin lymphoma, including patients with ataxia telangiectasia, X-linked lymphoproliferative disease, or Wiskott-Aldrich syndrome.
What are the symptoms of non-Hodgkin lymphoma?
Most children have stage III or IV disease at the time of diagnosis because of the sudden onset of symptoms. The disease can progress quickly from a few days to a few weeks. A child can go from otherwise healthy to having multi-system involvement in a short time period.
Some children with non-Hodgkin lymphoma have symptoms of an abdominal mass and have complaints of abdominal pain, fever, constipation, and decreased appetite due to the pressure and obstruction a large tumor in this area can cause.
Some children with non-Hodgkin lymphoma have symptoms of a mass in their chest and have complaints of respiratory problems, pain with deep breaths (dyspnea), cough, and/or wheezing.
Because of the rapid onset of this malignancy, any respiratory symptoms can quickly worsen, causing a life-threatening emergency.
The following are the most common symptoms of non-Hodgkin lymphoma. However, each child may experience the symptoms differently. Symptoms may include: Painless swelling of the lymph nodes in neck, chest, abdomen, underarm, or groin.
Fever.
Sore throat.
Fullness in groin area from node involvement.
Bone and joint pain.
Night sweats.
Fatigue (tiring easily).
Weight loss/decreased appetite.
Itching of the skin.
Recurring infections.
The symptoms of non-Hodgkin lymphoma may resemble other blood disorders or medical problems.
Renal Tumors
The most common renal (kidney) tumor in children and adolescents is the Wilms tumor, followed by renal cell carcinoma, clear cell sarcoma of the kidney, rhabdoid tumor, and congenital mesoblastic nephroma.
What is a Wilms tumor?
Wilms tumor, also called nephroblastoma, is a malignant (cancerous) tumor originating in the cells of the kidney. It is the most common type of renal (kidney) cancer and accounts for about 6 percent of all childhood cancers.
Approximately 500 children in the US are diagnosed with Wilms tumor each year. The disease can occur at any age between infancy and 15 years, but, in most cases, the tumor is detected by the age of 3. This cancer affects males and females equally.
The tumor can be very large and it may spread (metastasize) to other body tissues. The most common site for Wilms tumor to metastasize is the lungs. Lesions may also occur, however, in the liver, the other kidney, brain, and/or bones. In approximately 5 to 10 percent of children with Wilms tumor, both kidneys are involved.
What are the causes of a Wilms tumor?
It is uncommon for Wilms tumor to run in families. Less than 2 percent of cases will have an affected relative. Most cases of Wilms tumor are considered sporadic (occur by chance) and are the result of genetic mutations that affect cell growth in the kidney. These mutations generally arise after birth, but, in some cases, children are born with a genetic alteration that predisposes them to cancer.
A small percentage of patients with Wilms tumor have one of three genetic syndromes, including the following:
WAGR syndrome. The acronym WAGR stands for the four diseases present in WAGR syndrome, including: Wilms tumor, aniridia (absence of the iris, the colored part of the eye), genitourinary malformations, and mental retardation. This is caused by loss or inactivation of a tumor suppressor gene called WT1 on chromosome #11. Tumor suppressor genes usually suppress the growth of tumors and control cell growth. When altered, they no longer control cell growth, and tumors may form.
Denys-Drash syndrome is characterized by kidney failure, genitourinary malformations, and tumors of the gonads (ovaries or testes). This is also caused by loss or inactivation of a tumor suppressor gene called WT1 on chromosome #11. Tumor suppressor genes usually suppress the growth of tumors and control cell growth. When altered, they no longer control cell growth, and tumors may form.
Beckwith-Wiedemann syndrome is characterized by large birthweight and a large liver, spleen, and tongue; low blood sugar in neonatal period, malformations around the ear, asymmetric growth of the body, abdominal wall defects near the navel (omphalocele), and tumors of the liver and adrenal glands. This is thought to be caused by an overactive copy of an oncogene on chromosome #11, called IGF2. Oncogenes control cell growth, but, if mutated, uncontrolled cell growth may result.
What are the symptoms of a Wilms tumor?
The following are the most common symptoms of Wilms tumor. However, each child may experience symptoms differently. Symptoms may include:
A non-tender mass, or lump, felt or seen in the abdomen.
Swelling of the abdomen.
Veins that appear distended or large across the abdomen.
Blood in the urine (hematuria).
Pain in the abdomen from pressure on other organs near the tumor.
Decreased appetite and weakness or tiredness.
Fever.
High blood pressure (hypertension).
If a tumor is suspected in the child's abdomen, it is important not to apply pressure to this area. Careful bathing and handling of the child is necessary before and during any tumor evaluation. Rupture of the tumor may lead to cancer cells spreading to other tissues in the body.
These symptoms of Wilms tumor may resemble other medical conditions or serious illnesses.
Rhabdomyosarcoma
What is rhabdomyosarcoma?
Rhabdomyosarcoma accounts for approximately 3 percent of childhood cancers. In the US, about 350 children are diagnosed with rhabdomyosarcoma each year. This disease affects children between the ages 2 and 20 years of age, but can occur at any age. For unknown reasons, males are affected slightly more often than females.
Rhabdomyosarcoma is a cancerous tumor that originates in the soft tissues of the body, including the muscles, tendons, and connective tissues. The most common sites for this tumor include the:
Head
Neck
Bladder
Vagina
Arms
Legs
Trunk
Rhabdomyosarcoma can also be found in places where skeletal muscles are absent or very small, such as in the prostate, middle ear, and bile duct system. The cancer cells associated with this disease can spread (metastasize) to other areas of the body.
What are the types of rhabdomyosarcoma?
Embryonal rhabdomyosarcoma, the most common type, usually occurs in children under 6 years of age.
Alveolar rhabdomyosarcoma occurs in older children and accounts for about 20 percent of all cases.
What are the causes of rhabdomyosarcoma?
Some rhabdomyosarcoma tumors are believed to begin developing in the fetus. Rhabdomyoblasts are the cells at the initial stages of development of an unborn baby. These cells will mature and develop into muscles. There has been much research into the gene structure of these rhabdomyoblasts and possible detection of a gene error that can produce the disease later in development.
Rhabdomyosarcomas usually have some type of chromosome abnormality in the cells of the tumor, which are responsible for the tumor formation. In children with an embryonal rhabdomyosarcoma, there is usually an abnormality of chromosome #11. In alveolar rhabdomyosarcoma, a rearrangement in the chromosome material between chromosomes #2 and #13 is usually present. This rearrangement changes the position and function of genes, causing a fusion of genes referred to as a fusion transcript. Patients have an abnormal fusion transcript involving two genes known as PAX3 and FKHR. This important discovery has led to improvements in diagnosing rhabdomyosarcoma.
Rhabdomyosarcomas are also more common in children with neurofibromatosis or Li-Frameni syndrome, which are genetic disorders. Li-Frameni syndrome is a clustering of soft tissue cancers in a family, caused by mutations in a tumor suppressor gene called p53, which results in uncontrolled cell growth.
There has been no association between rhabdomyosarcoma and environmental exposures.
What are the symptoms of rhabdomyosarcoma?
The following are the most common symptoms of rhabdomyosarcoma. However, each child may experience symptoms differently. Many symptoms depend on the size and the location of the tumor. Symptoms may not be present until the tumor is very large, especially if it is located deep in the muscle or in the stomach. Symptoms may include:
A tumor or mass that can be seen or felt, but may or may not be painful.
Bleeding from the nose, vagina, rectum, or throat may occur if the location of the tumor is in these areas.
Tingling, numbness, pain, and movement may be affected if the tumor compresses nerves in the area.
Protrusion of the eye or a drooping eyelid may indicate a tumor behind the area.
The symptoms of rhabdomyosarcoma may resemble other conditions or medical problems.