Hydatidiform mole
Encyclopedia
Molar pregnancy is an abnormal form of pregnancy
, wherein a non-viable, fertilized egg implants in the uterus, and thereby converts normal pregnancy processes into pathological ones. It is characterized by the presence of a hydatidiform mole (or hydatid mole, mola hydatidosa). Molar pregnancies are categorized into partial and complete moles.
A complete mole is caused by a single (90%) or two (10%) sperm combining with an egg which has lost its DNA
(the sperm then reduplicates forming a "complete" 46 chromosome
set) The genotype
is typically 46,XX (diploid) due to subsequent mitosis
of the fertilizing sperm, but can also be 46,XY (diploid). In contrast, a partial mole occurs when an egg is fertilized by two sperm or by one sperm which reduplicates itself yielding the genotypes of 69,XXY (triploid) or 92,XXXY (quadraploid). Complete hydatidiform moles have a higher risk of developing into choriocarcinoma
— a malignant tumor of trophoblast
cells — than do partial moles.
The etymology
is derived from hydatisia (Greek
"a drop of water"), referring to the watery contents of the cysts, and mole (from Latin
mola = millstone/false conception). The term, however, comes from the similar appearance of the cyst to a hydatid cyst in an Echinococcosis
.
A hydatidiform mole conception may be categorized in medical terms as one type of non-induced (natural) "missed abortion". - referred to colloquially as a "missed miscarriage", because the pregnancy has become non-viable (miscarried) but was not immediately expelled (therefore was "missed").
in which the placenta
contains grapelike vesicles (small sacs) that are usually visible with the naked eye. The vesicles arise by distention of the chorionic villi
by fluid. When inspected in the microscope, hyperplasia
of the trophoblastic tissue is noted. If left untreated, a hydatidiform mole will almost always end as a spontaneous abortion (miscarriage).
Based on morphology
, hydatidiform moles can be divided into two types: In complete moles, all the chorionic villi
are vesicular, and no sign of embryo
nic or fetal development is present. In partial moles some villi are vesicular, whereas others appear more normal, and embryonic/fetal development may be seen but the fetus is always malformed and is never viable.
Hydatidiform moles are a common complication of pregnancy, occurring once in every 1000 pregnancies in the US, with much higher rates in Asia (e.g. up to one in 100 pregnancies in Indonesia).
In rare cases a hydatidiform mole co-exists in the uterus with a normal, viable fetus. These cases are due to twinning
. The uterus contains two conceptuses: one with an abnormal placenta and no viable fetus (the mole), and one with a normal placenta and a viable fetus. Under careful surveillance it is often possible for the woman to give birth to the normal child and to be cured of the mole.
The etiology
of this condition is not completely understood. Potential risk factors may include defects in the egg, abnormalities within the uterus
, or nutritional deficiencies. Women under 20 or over 40 years of age have a higher risk. Other risk factors include diets low in protein
, folic acid
, and carotene
. The diploid set of sperm-only DNA means that all chromosomes have sperm-patterned methylation
suppression of genes. This leads to overgrowth of the syncytiotrophoblast
whereas dual egg-patterned methylation leads to a devotion of resources to the embryo, with an underdeveloped syncytiotrophoblast. This is considered to be the result of evolutionary competition with male genes driving for high investment into the fetus versus female genes driving for resource restriction to maximise the number of children.
s are inherited from the father only (androgenesis). In approximately 80% of these androgenetic moles, the most probable mechanism is that an empty egg
is fertilized by a single sperm
, followed by a duplication of all chromosomes/genes (a process called "endoreduplication
"). In approximately 20% of complete moles the most probable mechanism is that an empty egg is fertilised by two sperm. In both cases, the moles are diploid (i.e. there are two copies of every chromosome). In all these cases, the mitochondrial genes are inherited from the mother, as usual.
Most partial moles are triploid (three chromosome sets). The nucleus contains one maternal set of genes and two paternal sets. The mechanism is usually the reduplication of the paternal haploid set from a single sperm, but may also be the consequence of dispermic (two sperm) fertilization of the egg.
In rare cases, hydatidiform moles are tetraploid (four chromosome sets) or have other chromosome abnormalities.
A small percentage of hydatidiform moles have biparental diploid genomes, as in normal living persons; they have two sets of chromosomes, one inherited from each biological parent. Some of these moles occur in women who carry mutation
s in the gene NLRP7
, predisposing them towards molar pregnancy. These rare variants of hydatidiform mole may be complete or partial.
may be larger than expected, or the ovaries
may be enlarged. There may also be more vomiting than would be expected (hyperemesis). Sometimes there is an increase in blood pressure
along with protein in the urine. Blood tests will show very high levels of human chorionic gonadotropin
(hCG).
The diagnosis is strongly suggested by ultrasound
(sonogram
), but definitive diagnosis requires histopathological examination
. On ultrasound, the mole resembles a bunch of grapes ("cluster of grapes" or "honeycombed uterus" or "snow-storm"). There is increased trophoblast
proliferation and enlarging of the chorionic villi
. Angiogenesis
in the trophoblasts is impaired as well.
Sometimes symptoms of hyperthyroidism
are seen, due to the extremely high levels of hCG, which can mimic the normal Thyroid-stimulating hormone
(TSH).
as soon as possible after diagnosis, in order to avoid the risks of choriocarcinoma
. Patients are followed up until their serum human chorionic gonadotrophin (hCG) level has fallen to an undetectable level. Invasive or metastatic moles (cancer
) may require chemotherapy
and often respond well to methotrexate
. The response to treatment is nearly 100%. Patients are advised not to conceive for one year after a molar pregnancy. The chances of having another molar pregnancy are approximately 1%.
Management is more complicated when the mole occurs together with one or more normal fetus
es.
Carboprost
medication may be used to contract the uterus
.
. The outcome after treatment is usually excellent. Close follow-up is essential. Highly effective means of contraception
are recommended to avoid pregnancy for at least 6 to 12 months.
In 10 to 15% of cases, hydatidiform moles may develop into invasive moles. This condition is named persistent trophoblastic disease
(PTD). The moles may intrude so far into the uterine wall that hemorrhage or other complications develop. It is for this reason that a post-operative full abdominal and chest x-ray
will often be requested.
In 2 to 3% of cases, hydatidiform moles may develop into choriocarcinoma
, which is a malignant, rapidly-growing, and metastatic
(spreading) form of cancer. Despite these factors which normally indicate a poor prognosis, the rate of cure after treatment with chemotherapy is high.
Over 90% of women with malignant, non-spreading cancer are able to survive and retain their ability to conceive and bear children. In those with metastatic (spreading) cancer, remission remains at 75 to 85%, although their childbearing ability is usually lost.
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
, wherein a non-viable, fertilized egg implants in the uterus, and thereby converts normal pregnancy processes into pathological ones. It is characterized by the presence of a hydatidiform mole (or hydatid mole, mola hydatidosa). Molar pregnancies are categorized into partial and complete moles.
A complete mole is caused by a single (90%) or two (10%) sperm combining with an egg which has lost its DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
(the sperm then reduplicates forming a "complete" 46 chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
set) The genotype
Genotype
The genotype is the genetic makeup of a cell, an organism, or an individual usually with reference to a specific character under consideration...
is typically 46,XX (diploid) due to subsequent mitosis
Mitosis
Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two cells containing roughly...
of the fertilizing sperm, but can also be 46,XY (diploid). In contrast, a partial mole occurs when an egg is fertilized by two sperm or by one sperm which reduplicates itself yielding the genotypes of 69,XXY (triploid) or 92,XXXY (quadraploid). Complete hydatidiform moles have a higher risk of developing into choriocarcinoma
Choriocarcinoma
Choriocarcinoma is a malignant, trophoblastic and aggressive cancer, usually of the placenta. It is characterized by early hematogenous spread to the lungs...
— a malignant tumor of trophoblast
Trophoblast
Trophoblasts are cells forming the outer layer of a blastocyst, which provide nutrients to the embryo and develop into a large part of the placenta. They are formed during the first stage of pregnancy and are the first cells to differentiate from the fertilized egg...
cells — than do partial moles.
The etymology
Etymology
Etymology is the study of the history of words, their origins, and how their form and meaning have changed over time.For languages with a long written history, etymologists make use of texts in these languages and texts about the languages to gather knowledge about how words were used during...
is derived from hydatisia (Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
"a drop of water"), referring to the watery contents of the cysts, and mole (from Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
mola = millstone/false conception). The term, however, comes from the similar appearance of the cyst to a hydatid cyst in an Echinococcosis
Echinococcosis
Echinococcosis, which is often referred to as hydatid disease or echinococcal disease, is a parasitic disease that affects both humans and other mammals, such as sheep, dogs, rodents and horses. There are three different forms of echinococcosis found in humans, each of which is caused by the larval...
.
A hydatidiform mole conception may be categorized in medical terms as one type of non-induced (natural) "missed abortion". - referred to colloquially as a "missed miscarriage", because the pregnancy has become non-viable (miscarried) but was not immediately expelled (therefore was "missed").
Natural history
A hydatidiform mole is a pregnancy/conceptusConceptus
Conceptus denotes the embryo and its adnexa or associated membranes . The conceptus includes all structures that develop from the zygote, both embryonic and extraembryonic...
in which the placenta
Placenta
The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. "True" placentas are a defining characteristic of eutherian or "placental" mammals, but are also found in some snakes and...
contains grapelike vesicles (small sacs) that are usually visible with the naked eye. The vesicles arise by distention of the chorionic villi
Chorionic villi
Chorionic villi are villi that sprout from the chorion in order to give a maximum area of contact with the maternal blood.Embryonic blood is carried to the villi by the branches of the umbilical arteries, and after circulating through the capillaries of the villi, is returned to the embryo by the...
by fluid. When inspected in the microscope, hyperplasia
Hyperplasia
Hyperplasia means increase in number of cells/proliferation of cells. It may result in the gross enlargement of an organ and the term is sometimes mixed with benign neoplasia/ benign tumor....
of the trophoblastic tissue is noted. If left untreated, a hydatidiform mole will almost always end as a spontaneous abortion (miscarriage).
Based on morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
, hydatidiform moles can be divided into two types: In complete moles, all the chorionic villi
Chorionic villi
Chorionic villi are villi that sprout from the chorion in order to give a maximum area of contact with the maternal blood.Embryonic blood is carried to the villi by the branches of the umbilical arteries, and after circulating through the capillaries of the villi, is returned to the embryo by the...
are vesicular, and no sign of embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
nic or fetal development is present. In partial moles some villi are vesicular, whereas others appear more normal, and embryonic/fetal development may be seen but the fetus is always malformed and is never viable.
Hydatidiform moles are a common complication of pregnancy, occurring once in every 1000 pregnancies in the US, with much higher rates in Asia (e.g. up to one in 100 pregnancies in Indonesia).
In rare cases a hydatidiform mole co-exists in the uterus with a normal, viable fetus. These cases are due to twinning
TWINS
Two Wide-Angle Imaging Neutral-Atom Spectrometers are a pair of NASA instruments aboard two United States National Reconnaissance Office satellites in Molniya orbits. TWINS was designed to provide stereo images of the Earth's ring current. The first instrument, TWINS-1, was launched aboard USA-184...
. The uterus contains two conceptuses: one with an abnormal placenta and no viable fetus (the mole), and one with a normal placenta and a viable fetus. Under careful surveillance it is often possible for the woman to give birth to the normal child and to be cured of the mole.
The etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
of this condition is not completely understood. Potential risk factors may include defects in the egg, abnormalities within the uterus
Uterus
The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
, or nutritional deficiencies. Women under 20 or over 40 years of age have a higher risk. Other risk factors include diets low in protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
, folic acid
Folic acid
Folic acid and folate , as well as pteroyl-L-glutamic acid, pteroyl-L-glutamate, and pteroylmonoglutamic acid are forms of the water-soluble vitamin B9...
, and carotene
Carotene
The term carotene is used for several related unsaturated hydrocarbon substances having the formula C40Hx, which are synthesized by plants but cannot be made by animals. Carotene is an orange photosynthetic pigment important for photosynthesis. Carotenes are all coloured to the human eye...
. The diploid set of sperm-only DNA means that all chromosomes have sperm-patterned methylation
Methylation
In the chemical sciences, methylation denotes the addition of a methyl group to a substrate or the substitution of an atom or group by a methyl group. Methylation is a form of alkylation with, to be specific, a methyl group, rather than a larger carbon chain, replacing a hydrogen atom...
suppression of genes. This leads to overgrowth of the syncytiotrophoblast
Syncytiotrophoblast
Syncytiotrophoblast is the epithelial covering of the placenta villous tree. It is a unique tissue in that it is a multi-nucleated, terminally differentiated syncytium, extending to 13m^2...
whereas dual egg-patterned methylation leads to a devotion of resources to the embryo, with an underdeveloped syncytiotrophoblast. This is considered to be the result of evolutionary competition with male genes driving for high investment into the fetus versus female genes driving for resource restriction to maximise the number of children.
Parental origin
In most complete moles, all nuclear geneNuclear gene
A Nuclear gene is a gene located in the cell nucleus of a eukaryote. The term is used to distinguish nuclear genes from the genes in the mitochondrion, and in case of plants, also the chloroplast, which host their own genetic system and can produce proteins from scratch...
s are inherited from the father only (androgenesis). In approximately 80% of these androgenetic moles, the most probable mechanism is that an empty egg
Ovum
An ovum is a haploid female reproductive cell or gamete. Both animals and embryophytes have ova. The term ovule is used for the young ovum of an animal, as well as the plant structure that carries the female gametophyte and egg cell and develops into a seed after fertilization...
is fertilized by a single sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
, followed by a duplication of all chromosomes/genes (a process called "endoreduplication
Endoreduplication
Endoreplication is replication of the nuclear genome in the absence of cell division, which leads to elevated nuclear gene content and polyploidy...
"). In approximately 20% of complete moles the most probable mechanism is that an empty egg is fertilised by two sperm. In both cases, the moles are diploid (i.e. there are two copies of every chromosome). In all these cases, the mitochondrial genes are inherited from the mother, as usual.
Most partial moles are triploid (three chromosome sets). The nucleus contains one maternal set of genes and two paternal sets. The mechanism is usually the reduplication of the paternal haploid set from a single sperm, but may also be the consequence of dispermic (two sperm) fertilization of the egg.
In rare cases, hydatidiform moles are tetraploid (four chromosome sets) or have other chromosome abnormalities.
A small percentage of hydatidiform moles have biparental diploid genomes, as in normal living persons; they have two sets of chromosomes, one inherited from each biological parent. Some of these moles occur in women who carry mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
s in the gene NLRP7
NLRP7
NACHT, LRR and PYD domains-containing protein 7 is a protein that in humans is encoded by the NLRP7 gene.- Function :NALPs are cytoplasmic proteins that form a subfamily within the larger CATERPILLER protein family...
, predisposing them towards molar pregnancy. These rare variants of hydatidiform mole may be complete or partial.
Clinical presentation and diagnosis
Molar pregnancies usually present with painless vaginal bleeding in the fourth to fifth month of pregnancy. The uterusUterus
The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
may be larger than expected, or the ovaries
Ovary
The ovary is an ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in anatomically female individuals are analogous to testes in anatomically male individuals, in that they are both gonads and endocrine glands.-Human anatomy:Ovaries...
may be enlarged. There may also be more vomiting than would be expected (hyperemesis). Sometimes there is an increase in blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
along with protein in the urine. Blood tests will show very high levels of human chorionic gonadotropin
Human chorionic gonadotropin
Human chorionic gonadotropin or human chorionic gonadotrophin is a glycoprotein hormone produced during pregnancy that is made by the developing embryo after conception and later by the syncytiotrophoblast .. Some tumors make this hormone; measured elevated levels when the patient is not...
(hCG).
The diagnosis is strongly suggested by ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
(sonogram
Medical ultrasonography
Diagnostic sonography is an ultrasound-based diagnostic imaging technique used for visualizing subcutaneous body structures including tendons, muscles, joints, vessels and internal organs for possible pathology or lesions...
), but definitive diagnosis requires histopathological examination
Histopathology
Histopathology refers to the microscopic examination of tissue in order to study the manifestations of disease...
. On ultrasound, the mole resembles a bunch of grapes ("cluster of grapes" or "honeycombed uterus" or "snow-storm"). There is increased trophoblast
Trophoblast
Trophoblasts are cells forming the outer layer of a blastocyst, which provide nutrients to the embryo and develop into a large part of the placenta. They are formed during the first stage of pregnancy and are the first cells to differentiate from the fertilized egg...
proliferation and enlarging of the chorionic villi
Chorionic villi
Chorionic villi are villi that sprout from the chorion in order to give a maximum area of contact with the maternal blood.Embryonic blood is carried to the villi by the branches of the umbilical arteries, and after circulating through the capillaries of the villi, is returned to the embryo by the...
. Angiogenesis
Angiogenesis
Angiogenesis is the physiological process involving the growth of new blood vessels from pre-existing vessels. Though there has been some debate over terminology, vasculogenesis is the term used for spontaneous blood-vessel formation, and intussusception is the term for the formation of new blood...
in the trophoblasts is impaired as well.
Sometimes symptoms of hyperthyroidism
Hyperthyroidism
Hyperthyroidism is the term for overactive tissue within the thyroid gland causing an overproduction of thyroid hormones . Hyperthyroidism is thus a cause of thyrotoxicosis, the clinical condition of increased thyroid hormones in the blood. Hyperthyroidism and thyrotoxicosis are not synonymous...
are seen, due to the extremely high levels of hCG, which can mimic the normal Thyroid-stimulating hormone
Thyroid-stimulating hormone
Thyrotrophin-stimulating hormone is a peptide hormone synthesized and secreted by thyrotrope cells in the anterior pituitary gland, which regulates the endocrine function of the thyroid gland.- Physiology :...
(TSH).
Treatment
Hydatidiform moles should be treated by evacuating the uterus by uterine suction or by surgical curettageCurettage
Curettage, in medical procedures, is the use of a curette to remove tissue by scraping or scooping.Curettages are also a declining method of abortion. It has been replaced by vacuum aspiration over the last decade....
as soon as possible after diagnosis, in order to avoid the risks of choriocarcinoma
Choriocarcinoma
Choriocarcinoma is a malignant, trophoblastic and aggressive cancer, usually of the placenta. It is characterized by early hematogenous spread to the lungs...
. Patients are followed up until their serum human chorionic gonadotrophin (hCG) level has fallen to an undetectable level. Invasive or metastatic moles (cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
) may require chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
and often respond well to methotrexate
Methotrexate
Methotrexate , abbreviated MTX and formerly known as amethopterin, is an antimetabolite and antifolate drug. It is used in treatment of cancer, autoimmune diseases, ectopic pregnancy, and for the induction of medical abortions. It acts by inhibiting the metabolism of folic acid. Methotrexate...
. The response to treatment is nearly 100%. Patients are advised not to conceive for one year after a molar pregnancy. The chances of having another molar pregnancy are approximately 1%.
Management is more complicated when the mole occurs together with one or more normal fetus
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...
es.
Carboprost
Carboprost
Carboprost is a synthetic prostaglandin analogue of PGF2α with oxytocic properties....
medication may be used to contract the uterus
Uterus
The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
.
Prognosis
More than 80% of hydatidiform moles are benignBenign
A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
. The outcome after treatment is usually excellent. Close follow-up is essential. Highly effective means of contraception
Contraception
Contraception is the prevention of the fusion of gametes during or after sexual activity. The term contraception is a contraction of contra, which means against, and the word conception, meaning fertilization...
are recommended to avoid pregnancy for at least 6 to 12 months.
In 10 to 15% of cases, hydatidiform moles may develop into invasive moles. This condition is named persistent trophoblastic disease
Gestational trophoblastic disease
Gestational trophoblastic disease is a term used for a group of pregnancy-related tumours. These tumours are rare, and they appear when cells in the womb start to grow out of control. The cells that form gestational trophoblastic tumours are called trophoblasts and come from tissue that grows to...
(PTD). The moles may intrude so far into the uterine wall that hemorrhage or other complications develop. It is for this reason that a post-operative full abdominal and chest x-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
will often be requested.
In 2 to 3% of cases, hydatidiform moles may develop into choriocarcinoma
Choriocarcinoma
Choriocarcinoma is a malignant, trophoblastic and aggressive cancer, usually of the placenta. It is characterized by early hematogenous spread to the lungs...
, which is a malignant, rapidly-growing, and metastatic
Metastasis
Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
(spreading) form of cancer. Despite these factors which normally indicate a poor prognosis, the rate of cure after treatment with chemotherapy is high.
Over 90% of women with malignant, non-spreading cancer are able to survive and retain their ability to conceive and bear children. In those with metastatic (spreading) cancer, remission remains at 75 to 85%, although their childbearing ability is usually lost.
External links
- Humpath #3186 (Pathology images)
- Original source:
- Clinically reviewed molar pregnancy and choriocarcinoma information for patients from Cancer Research UKCancer Research UKCancer Research UK is a cancer research and awareness charity in the United Kingdom, formed on 4 February 2002 by the merger of The Cancer Research Campaign and the Imperial Cancer Research Fund. Its aim is to reduce the number of deaths from cancer. As the world's largest independent cancer...