Choriocarcinoma is a trophoblastic tumor that develops as a result of malignant transformation of the chorionic epithelium. The clinic characterized by bloody, serous or purulent discharge from the genital tract, pain in the lower abdomen; with metastasis – symptoms from the relevant organs. Diagnosis requires determination of the level of HCG and trophoblastic globulin in the blood, histological analysis of scraping, ultrasound. Treatment may include chemotherapy, surgery.
C58 Malignant neoplasm of the placenta
Choriocarcinoma refers to malignant forms of trophoblastic disease, which occurs in 0.5-8.3 cases per 1000 births. Most often, the development of choriocarcinoma is preceded by cystic drift (40% of cases), abortion (25%), childbirth (22.5%), ectopic pregnancy (2.5%). Less common are teratogenic choriocarcinomas that are not associated with pregnancy. In rare cases, a simultaneous combination of cystic drift and choriocarcinoma is possible. Choriocarcinoma is more often diagnosed in residents of the Asian region.
The question of the causes of the development of choriocarcinoma, as other forms of trophoblastic disease, requires further study. Viral transformation of trophoblast, immunosuppressive effect of pregnancy hormones (HCG, progesterone, estrogens), metabolic disorders, immunological conflict, protein deficiency, increased enzymatic activity of hyaluronidase are considered as the leading etiopathogenetic link.
Risk categories for the development of this disease include:
- pregnant women over 40 years old;
- repeat pregnancies;
- women with a history of abortions, miscarriage, ectopic pregnancy;
- patients who have suffered a bubble drift.
Choriocarcinoma is formed from the structures of the trophoblast, syncytial tissue of chorionic villi, sometimes from germ cells of the gonads. According to the macroscopic structure, pathology is a dark hemorrhagic mass of soft consistency with zones of ulceration and decay. Microscopic examination determines the promiscuous proliferation of trophoblast tissue, the absence of stroma, vessels and chorionic villi; the presence of Langhans cells and syncytial elements.
Choriocarcinoma is usually located in the uterine body (in the area of the previous implantation of the embryo), where it can have submucous (83%), intramural (5, 6%) or subserous (7%) localization. In the ectopic form, primary foci of choriocarcinoma can be detected in the ovaries and fallopian tubes (1-4%); brain, lungs, vagina (17%).
According to the place of development of the primary focus in clinical gynecology, orthotopic, heterotopic and teratogenic choriocarcinoma are distinguished. With orthotopic form, the tumor is localized at the site of the previous implantation of the fetal egg – the uterus, tubes, and abdominal cavity. As it progresses, disease germinates and metastasizes into the vagina, parametrium, large omentum, bladder, rectum or sigmoid colon, lungs.
Choriocarcinoma with heterotopic localization is initially detected outside the embryo implantation zone, more often in the walls of the vagina, lungs, and brain. Teratogenic choriocarcinoma is not associated with previous pregnancy and refers to mixed tumors of embryonic genesis. The location of teratogenic choriocarcinomas is extragonadal – in the epiphysis, lungs, mediastinum, stomach, retroperitoneal space, bladder.
In the staging of choriocarcinomas, they adhere to the WHO classification, distinguishing stages IV:
- I – localization of choriocarcinoma is limited to the uterus
- II – tumor growth spreads beyond the uterus, but is limited to the genitals
- III – metastases to the lungs are detected
- IV – metastases of organs other than the lungs are detected.
Choriocarcinoma can develop simultaneously with pregnancy, shortly after the end of gestation, or occur several years after pregnancy. Initially, 80% of patients have spotting of varying intensity and duration. The periodic independent cessation of bleeding and the ineffectiveness of separate therapeutic and diagnostic curettage are specific.
Bleeding, as a rule, begins shortly after a medical abortion, childbirth, miscarriage; sometimes – after a long delay of menstruation or in the intermenstrual interval. Along with blood secretions in choriocarcinoma, it is possible to isolate serous or purulent whites associated with necrosis or infection of the tumor node. Breast swelling is often detected with the release of colostrum-like secretions from the nipples.
Repeated bleeding leads to anemia; intoxication is accompanied by fever and chills. When the tumor masses of the uterus body germinate, the appearance of pain syndrome in the lower abdomen and lower back is noted. The presence of metastases in the lungs is indicated by cough and hemoptysis; in the brain – neurological symptoms (visual impairment, headache, dizziness, motor disorders). With choriocarcinoma, metastatic lesion of the lungs (45-50%), vagina (35%), appendages, cervix, brain occurs more often. In the ovaries with choriocarcinoma, tecalyutein cysts are often detected.
Since the symptoms of choriocarcinoma are not very specific, objective diagnosis is of great importance. When studying the anamnesis, the connection with previous pregnancy, bladder drift is taken into account. To assess the objective status , the following is done:
- Examination on the chair. Gynecological examination allows you to detect the presence of cyanotic nodes sprouting into the vagina; with the development of choriocarcinoma during pregnancy, there is an increase in the size of the uterus compared to the gestational period.
- Radiation methods. Ultrasound of the pelvic organs reveals an enlargement of the uterus, the presence of small-cystic tissue in the uterus, bilateral tecalyutein cysts. The tumor node of choriocarcinoma can have dimensions from several centimeters to the size of an adult’s head. For clarifying purposes, hysterography is used – an X-ray examination of the uterus.
- SDC. Carrying out diagnostic curettage of the uterine cavity with histological examination of scraping is not always informative, since micro-preparations often contain blood clots, necrotic endometrial tissues and single elements of the trophoblast. Choriocarcinoma is indicated by the detection of atypical syncytiotrophoblast cells in the scraping. It is possible to conduct a cytological examination of smears-prints from the affected tissues of the vagina, vulva, cervix, as well as biopsies of these areas.
Choriocarcinoma can be difficult to differentiate from a trophoblastic tumor of the placental site and invasive cystic drift, which also differ in infiltrating growth. A typical diagnostic sign of choriocarcinoma is the determination of elevated levels of hCG, AFP and trophoblastic β-globulin in the blood serum, which are excessively produced by the tumor. With the help of radiography, lung tomography and CT of the brain, the presence of choriocarcinoma metastases in distant organs is determined.
Treatment of choriocarcinoma
The leading method of treating choriocarcinoma is mono- or polychemotherapy. The first-line drugs are methotrexate, cisplatin, calcium folinate, actinomycin D, vincristine, cyclophosphamide, mercaptopurine, etc., which are prescribed independently or in various combinations in repeated courses of 8-15 days.
Surgical treatment of choriocarcinoma is resorted to with threatening bleeding, the risk of uterine perforation, septic conditions, ineffective chemotherapy, significant damage to the uterus and ovaries. The recommended volume of intervention is the removal of the uterus: hysterectomy (in the absence of metastases in young women) or pangisterectomy (in women over 40 years old). Removal of choriocarcinoma is further supplemented by chemotherapeutic treatment. The criterion of cure is the normalization of the level of HCG in three analyses performed at intervals of 1 week.
Prognosis and prevention
During remission, regular monitoring of the HCG titer is necessary (once every 2 weeks for 3 months, then once every 6 months for 2 years); lung radiography (every 3 months for a year). For a long time, at least for 1 year, the patient is prescribed hormonal contraception COC.
Preventive chemotherapy is indicated for patients with cystic drift who have a high risk of transformation into choriocarcinoma. The presence of metastases reduces the possibility of cure by up to 70%. With ovarian choriocarcinoma, which does not respond well to chemotherapy, the prognosis is almost always unfavorable.