A partial hydatidiform mole is a completely independent ailment to complete hydatidiform mole. When the proliferationinvasion phenomena are not well controlled, the trophoblast cells can give rise to a rare complication of pregnancy known as a hydatidiform mole complete or partial. It is the most common form of the disease, and it is benign in nature. A triploid zygote fertilization by 2 spermatozoa leading to a partial hydatidiform mole phm but can also lead to haploid and diploid clones. The two distinct types of hm, complete mole and partial mole, have different karyotypes, gross and microscopic histopathology, clinical presentations, and prognoses. Current clinical features of complete and partial hydatidiform mole. All patients admitted for uterine evacuation for nonviable pregnancy were included. A hydatidiform mole is a growing mass of tissue inside the womb uterus that will not develop into a baby. Molar pregnancy hydatidiform mole is known as the premalignant form of gestational trophoblastic neoplasia. Background partial hydatidiform moles pms rarely require chemotherapy and have never previously been proven to transform into choriocarcinoma, the most. Just remember that if it is complete it is an empty ovum meaning there is an abnormal sac but no fetus.
Ten percent of partial moles represent tetraploid or mosaic conceptions. Overrepresentation of the paternal genome in sporadic hydatidiform moles purely androgenetic in complete hydatidiform moles and diandric triploid in partial hydatidiform moles. The unique genetics of complete hydatidiform moles purely androgenetic, partial hydatidiform moles diandric triploid, and nonmolar specimens biparental, with allelic balance allow for certain techniques, including immunohistochemical analysis of p57 expression a paternally imprinted, maternally expressed gene and genotyping, to refine diagnoses of hydatidiform moles. A complete hydatidiform mole is most often derived from a single sperm fertilizing an ovum that lacks maternal dna and then undergoing endoreduplication. A complete molar pregnancy consists of diffuse hydropic chorionic villi with trophoblastic hyperplasia, forming a mass of multiple vescicles. Hydatidiform mole is a disease of pregnancy and therefore a disease of women. Persistent gestational trophoblastic disease develops after a cm in 10% to 30% of cases and after a pm in 0. Complete moles are usually diploid and androgenetic, pathologically dem onstrating minimal embryonal development. A hydatidiform mole may be either complete or partial. An information guide for patients diagnosed with partial. Hydatidiform mole definition of hydatidiform mole by.
Molar pregnancies are classified as either partial or complete. Definition a hydatidiform mole is a relatively rare condition in which tissue around a fertilized egg that normally would have developed into the placenta instead develops as an abnormal cluster of cells. This was a crosssectional study carried out from november 2016 to february 2017. The mechanism of origin of the additional haploid complement was found to be highly correlated with the development of partial hydatidiform mole and with gestational age. Update on the pathology of gestational trophoblastic. As a booklet, it provides basic information about a molar pregnancy and the required followup.
Partial moles occur, in almost all cases, following dispermic fertilisation of an ovum. About gestational trophoblastic disease what is gestational. It is characterized by the appearance of a voluminous mass of swollen and sometimes, cystically dilated chorionic villi appearing grossly as grapelike structure. All 51 paternally derived triploids in which a pathologic diagnosis could be made were partial moles, whereas only 3 of 15 maternally derived triploids on which a diagnosis.
Partial molar pregnancies have a normal to slightly larger placental volume than. While hydatidiform pregnancies are relatively rare, eps should be aware of the clinical and sonographic features of these diseases. Gestational trophoblastic neoplasia gtn is a term used to describe gtd requiring chemotherapy. Pdf to describe the current clinical presentation of complete chm and partial phm hydatidiform mole in a swedish setting. These droplets appear to burrow into the wall of the uterus, hence the name mole. Hydatidiform moles are intriguing pathologic entities representing abnormal placental villous tissue with unique genetic profiles and a wide spectrum of morphologic features, which makes accurate diagnosis challenging. The swollen villi grow in clusters that look like bunches of grapes. There are two types of molar pregnancy, complete molar pregnancy and partial molar pregnancy.
We sought to determine the prevalence of and factors associated with hydatidiform molar gestations amongst patients undergoing uterine evacuation at mbarara regional referral hospital mrrh, mbarara, uganda. In the united states, hydatidiform moles hms complicate approximately 1 in 1,500 pregnancies and are classified as complete moles cms or partial moles pms based on clinical, morphologic, and genetic differences. The first part of the name hydatidiform comes from the greek word hydatid meaning droplet. This is called a molar pregnancy, but it is not possible for a normal baby to form. Gestational trophoblastic disease comprises a spectrum of disorders from the benign hydatidiform mole complete and partial through to the malignant invasive mole, choriocarcinoma, and the rare placental siteepithelioid trophoblastic tumour. Progression to gestational trophoblastic neoplasia gtn occurs in 515% of cases of complete mole and in % of cases of partial mole 3. All cases could be categorized in to two groups, complete or partial hydatidiform mole. Partial hydatidiform moles are formed by a dispermic fertilization of a normal ovum leading to a triploid pattern, and are clinically distinguished from complete molar pregnancies because affected patients have a uterus that is often small for gestational age. In a partial mole, there is usually evidence of a fetus or fetal red blood cells. Alternatively, two different sperm may fertilize the ovum. Women in their early teenage or perimenopausal years are most at risk. Risk of recurrent hydatidiform mole and subsequent. Prevalence and factors associated with hydatidiform mole. Lurain, md g estational trophoblastic disease gtd is a spectrum of cellular proliferations arising from the placental villous trophoblast encompassing 4 main clinicopathologic forms.
The most common form of gestational trophoblastic disease gtd is a hydatidiform mole, also known as a molar pregnancy. The pregnancy is not viable, and the normal pregnancy process turns into a benign tumour. Hydatidiform mole is a product of anomalous conceptions, with prevalence about 1 in 500 pregnancies 6. Figure 1 parental contributions to molar pregnancies. Hydatidiform mole is more common at the extremes of reproductive age.
Partial mole and triploidy 64 of 832 specimens triploid 8% 23 are diandric half, or total were partial moles most of the remainder showed some but not all features of a partial mole. Subsequent pregnancy outcome in patients with spontaneous. In a partial molar pregnancy, a fetus develops but it will be abnormal and cannot survive. Partial hydatidiform mole results from the fertilization of a normal egg by two spermatozoa dispermic, 90% or fertilization by one spermatozoa followed by duplication of the paternal chromosomal content monospermic, 10% as a result, partial moles have a. These hydatidiform moles belong to the gestational trophoblastic diseases of which represent the most common pathologies.
Conclusions women having a pregnancy affected by a histologically confirmed complete or partial hydatidiform mole may be counselled that the risk of repeat mole in a subsequent pregnancy is about 1 in. In a complete molar pregnancy, the growth stops a fetus from developing. Here, we report an unusual presentation of complete hydatidiform mole, which exhibited prominent. These are genetically different lesions, with complete moles usually comprised of a diploid complement, both paternally derived, while partial moles are diandric triploids in most cases. A molar pregnancy also known as hydatidiform mole is a rare complication of pregnancy characterized by the abnormal growth of trophoblasts, the cells that normally develop into the placenta. This case, particularly given the atypical clinical presentation for a partial molar pregnancy, highlights the importance of ultrasound in pregnancy, and the utility of bedside ultrasound in the evaluation of the etiology of vaginal bleeding in the early pregnant. Partial hydatidiform mole results from the fertilization of a normal egg by two spermatozoa dispermic, 90% or fertilization by one spermatozoa followed by duplication of the paternal chromosomal content monospermic, 10% as a result, partial moles have a triploid genome, diandric and monogynic. Partial hydatidiform moles do not have the same presenting features as complete moles. Repeat molar pregnancy is the only unfavourable event in subsequent pregnancy in patients with complete and partial moles, and the incidence is increased 5fold compared with the general population.
The management of gestational trophoblastic disease rcog. A complete hydatidiform mole most often develops when 1 or 2 sperm cells fertilize an egg cell that. Hydatidiform mole hm is one of a group of diseases that develop from abnormal proliferation of trophoblast and are classified as gestational trophoblastic disease gtd. Hydatidiform mole an overview sciencedirect topics. Case report complete hydatidiform mole with massive. At most, the fetus might survive for around three months. Molar pregnancy, partial and complete hydatidiform mole presented by usmle ace, inc. Although the main presenting symptom is also vaginal bleeding, which occurs in about 75% of patients, excessive uterine enlargement, hyperemesis, pregnancyinduced hypertension, hyperthyroidism, and theca lutein cysts develop infrequently. Molar pregnancies are categorized as partial moles or complete moles, with the word mole being used to denote simply a clump of growing tissue, or a growth. The placenta becomes larger than normal and contains a number of cysts sacs of fluid. Gtd hydatidiform mole, invasive mole, choriocarcinoma, placentalsite trophoblastic tumour is a rare. Clinical and cytogenetic comparison of hydatidiform moles and hydropic abortus. Diagnosis based on morphology is subject to interobserver variability. Choriocarcinoma and partial hydatidiform moles the lancet.
Partial hydatidiform mole presents to the physician as a mixture of normal villous placental trophoblastic tissue, hygromatous balls or cysts, and some fetal fragments, without an intact fetus. This is an ovum not carrying any chromosomes or genetic material. Hydatidiform moles are abnormal placentas in which an excess of paternal relative to maternal dna material is present. It is made up of villi that have become swollen with fluid. Risk of partial and complete hydatidiform molar pregnancy in. The complete hydatidiform mole is usually diploid and entirely androgenetic in origin. Sometimes, during conception, a sperm fertilises an empty egg ovum. The management of gestational trophoblastic disease. This grapelike mass forms inside of the uterus after fertilization instead of a. Hydatidiform moles are divided into complete and partial hydatidiform moles.
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