Pathological Disorders Of The Female Placenta PDF

Pathological disorders of the placenta  Introduction What is 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. Pathology of placenta involves two main problems, di...

Pathological disorders of the placenta  Introduction What is 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. Pathology of placenta involves two main problems, disorders of placenta during pregnancy and the developing of choriocarcinoma  Placental disorders during pregnancy Placenta accreta: A rare disorder in which the chorionic villi are deeply attached to be immediately adjacent myometrium or even may penetrate it to a varying degrees with the association deficient decidua (the basal plate) and these abnormalities make the detachment of the placenta after delivery not easy with the possibility of severe post partum hemorrhage. It may be due to a previous operation. There are three forms of placenta accreta, distinguishable  by the depth of penetration. ❖Placenta accreta—the placenta grows into the lining of the uterus.... ❖Placenta increta—the placenta grows into the wall of the uterus. ❖Placenta percreta—the placenta grows through the wall of the uterus, at times into nearby organs such as the bladder or colon. The three types of Placenta accreta This disorder affects approximately 1 in 2,500 pregnancies. The placenta usually detaches from the uterine wall relatively easily, but women who have placenta accreta during childbirth are at risk of hemorrhage during its removal. This post partum hemorrhage may be sever and fatal. It commonly requires surgery to remove the placenta, and sometimes hysterectomy may be needed. Placenta previa: This is an obstetric disorder in which the placenta site is not normal and it attached to the uterine wall close to or covering the cervix and this may lead to antepartum hemorrhage. This hemorrhage can sometimes occur in the later part of the first trimester, but it usually occurs during the second or third trimester. There are three types of placenta previa; ❖Marginal: The placenta is next to the cervix but does not cover the opening. ❖Partial: The placenta covers part of the cervical opening. ❖Complete: The placenta covers all of the cervical opening. Placenta previa Types of placenta previa Placental abruption (Abruptio placentae): is a serious complication of pregnancy, wherein the placental lining has separated from the uterus causing late antepartum hemorrhage. It is the most common cause of late pregnancy bleeding and it occurs in 1% of pregnancies world wide with a fetal mortality rate of 20–40% depending on the degree of separation. Placental abruption is also a significant contributor to maternal mortality. Placental abruption  Inflammation: Almost always related to an infection that occurs by one of these two ways; – Ascending infection from the birth canal leading to chorioamnionitis and umbilical cord vasculitis. – Hematogenous infections derived from a maternal septicemia, leading to villous inflammation (villitis). The organisms include: streptococci, toxoplasma, rubella, syphilis, cytomegalovirus and herpes virus. Fetal infection and abortion are well known complications. Septicemia of mother beside pelvic sepsis and DIC are other expected complications.  Hydatidiform complete mole: It is an abnormal pregnancy like condition in which an embryo is completely absent and the placental villi are avascular and large because they are distended by fluid and it associates with chromosomal disorder and inevitably ends with abortion. The villi appear as small grape like cystic structures filled with translucent fluid. These villi measure up to 1 cm, or even more, in diameter. No trace of an embryo, amniotic sac, or umbilical cord. This disease occurs most commonly in women aged less than 18 or more than 40 years. The chromosomal constitution of this complete mole is androgenetic (i.e. of paternal origin), characteristically 46xx and is probably due to the fertilization of an empty ovum by a spermatozoon carrying x chromosome which is then reduplicated. The hydatidiform mole usually grows faster than a normal pregnancy and the patient may present either with a large for dates uterus, or with bleeding in early pregnancy. There is high level of human chorionic gonadotrophin hormone (HCG). The mole leads inevitably to abortion. The woman with mole history has a 2-3% risk of the eventually developing of choriocarcinoma. There is a clearcut relationship between hydatidiform mole and the development of choriocarcinoma. The atypical villous hyperplasia is almost a constant finding, but sometimes it is marked and the mole shows invasive features (hence called invasive mole). This invasive behavior occurs in about 10% of all molar pregnancies. This invasive extension of the hyperplastic villi penetrates and may even perforate the uterine wall but still the situation is defined as a benign, not neoplastic state. Unfortunately, neither the high degrees of atypical villous trophoblastic hyperplasia, nor the invasive features, can be taken as a clearcut measurement for the future risk (prognosis) of developing choriocarcinoma. Hydatidiform complete mole  Hydatidiform complete mole Normal villi complete mole villi Hydatidiform complete mole Partial mole: An abnormal placenta in which only a minority of villi show hydatidiform like change with the presence of atypical trophoblastic proliferation and presence of grossly abnormal fetal parts, and the condition associates with a triploidy chromosomal abnormality. It is not a true variant of hydatidiform mole. The triploidy chromosomal abnormality in the fetus is mostly consist of one maternal and two paternal haploid sets of chromosomes. One egg gets fertilized by two sperms. Then the egg has 69 chromosomes (69 xxy, or 69xxx or 69xyy) Partial mole  Choriocarcinoma A rare highly malignant tumor of the placenta that formed of both cytotrophoblast and syncytiotrophoblast tissues and it associates generally with abortive previous pregnancies. It considered as a unique neoplasm in that, being of purely fetal origin. It may follow hydatidiform mole (50%), abortion (25%), normal pregnancy or ectopic pregnancy. The etiology is unknown. This tumor, like hydatidiform mole, secretes placental human chorionic gonadotrophin hormone (HCG). Assay of serum and urinary levels of this tumor marker are used for patient diagnosis and follow up. Because trophoblast has an inherent capacity for invading blood vessels, this tumor is seen within the uterus as a soft, largely hemorrhagic mass. Microscopically the mononuclear cytotrophoblast seen surrounded by a rim of multinucleated syncytiotrophoblast and both cells show variable degree of pleomorphism and mitotic activity but no villi are present. Blood spread occurs at an early stage, principally to the lungs, liver, brain and vagina. Fortunately, nowadays there is a high response of this cancer to chemotherapy and at least 80% of patients are now permanently cured following such treatment. Choriocarcinoma Choriocarcinoma