Pathology of gestational trophoblastic tumors

Gestational trophoblastic tumours result from an abnormal proliferation of different types of trophoblasts. The morphological pattern, together with the immunohistochemical aspect, the cytogenetic data and the clinical profile, helps identify each pathological entity. Hydatiform moles represent malformed placentas caused by genetic aberrations of the villous trophoblast. A complete hydatiform mole displays an hydropic degeneration of all the chorionic villi with a more or less marked proliferation of trophoblasts. A partial hydatiform mole is made up of molar vesicles interspersed with normal chorionic villi. In an invasive hydatiform mole or chorioma destruens, molar vesicles penetrate the myometrium giving rise to a mass distorting the uterine wall. A choriocarcinoma is a malignant proliferation of atypical villous trophoblasts without villi formation. Necrosis, haemorrhage, vascular invasion and distant metastases strongly compromise its outcome. A trophoblastic implantation site tumor, clearly less frequent, results from a proliferation of extravillous trophoblasts, particular for their secretion of human placental lactogen hormone (hPL). This tumour, exceptionally malignant, should be differentiated from the exaggerated placental site and its variants. Except for the placental site trophoblastic tumour, and whatever the outcome (benign or malignant), all gestational trophoblastic tumours secrete the beta-subunit of the chorionic gonadotropic hormone (beta-hCG) more or less abundantly. The serum or urinary level of this unit is proportional to the tumour volume and represents a fundamental basis for the follow-up of these tumours. Multidisciplinary care of high-risk cases allows us to cure the disease, and helps the patient recover her reproductive uterine function.     

Uterine perforation revealing a rare placental tumor: trophoblastic tumor of the implantation site. Review of the literature. Apropos of a case

The trophoblastic tumor of the implantation site (TTIS), recently discovered, is a peculiar and rare choriocarcinoma; the authors are reporting the 36th case in the world. Clinically, it is different from the typical choriocarcinoma by amenorrhea, frequent uterine perforations and negative pregnancy tests. The diagnosis is made histologically; most important are the monomorphic tumor cells, and especially, the immunocytochemical labelling for human chorionic gonadotropic hormone and lactogenic placental hormone permitting the differentiation of TTIS in choriocarcinoma from TTIS in non-trophoblastic tumors. Its course is highly malignant in 25 p. cent of the cases without any absolute prognostic factor at this time. The treatment is not codified; it seems that, unlike in the typical choriocarcinoma, a place of choice should be given to surgery, since the usual chemotherapy of trophoblastic tumors has not proved to be effective in this indication. On the contrary, monitoring will be supported by serum hCG assays.     

Epithelioid trophoblastic tumor of the lung

Epithelioid trophoblastic tumor (ETT) is a rare type of gestational trophoblastic disease and only 25 cases have been reported so far. It was first proposed by Mazur and Kurman in 1994 as an unusual type of trophoblastic tumor that is distinct from placental site trophoblastic tumor and choriocarcinoma and has features resembling carcinoma. A case of ETT of the lung in a 38-year-old Japanese woman is reported. The patient had suffered from a hydatidiform mole at the age of 27 years, and had four normal deliveries at the ages of 24, 31, 35 and 37 years. Because no tumor lesions were detected in the uterus, the patient was suspected of having metastatic choriocarcinoma with multiple lesions in the lung accompanied by an elevated level of human chorionic gonadotropin (hCG). In order to make an exact diagnosis, a partial resection of metastatic foci in the lung was performed. Microscopically, the tumor showed hemorrhagic necrotic foci and was composed of mainly mononuclear tumor cells and some giant tumor cells resembling trophoblastic cells. Immunohistochemical examination showed that a few large cells were stained positively for hCG, and that other cells were positive for human placental lactogen, pregnancy-specific beta1-glycoprotein, cytokeratin 7 and inhibin-alpha. In the ultrastructure, the tumor cells contained large nuclei and rich organella with desmosomes and well-formed filaments. The diagnosis of ETT was confirmed from the findings as described above.     

Immunocytochemical localization of placental lactogen and chorionic gonadotropin in the normal placenta and trophoblastic tumors, with emphasis on intermediate trophoblast and the placental site trophoblastic tumor

This report presents preliminary observations on the immunocytochemical localization of human chorionic gonadotropin (hCG) and human placental lactogen (hPL) in placental site trophoblastic tumors, hydatidiform moles, and choriocarcinomas and compares the findings with those of a similar immunocytochemical analysis of the placenta at various stages of development. In addition to cytotrophoblast (CT) and syncytiotrophoblast (ST), a third form of trophoblast designated "intermediate trophoblast" (IT) is present during normal pregnancy and in trophoblastic disease. Intermediate trophoblastic cells are mononucleate, larger than CT, and contain more abundant eosinophilic cytoplasm, resulting in a partial resemblance to ST. Intermediate trophoblast has distinctive immunocytochemical features that distinguish it from CT and ST. The localization of hPL and hCG in both IT and ST varies with the age of the placenta, with the type of trophoblastic neoplasm, and from one specimen to another within each category of tumor. Syncytiotrophoblast may contain both hormones in large amounts, whereas IT contains hPL predominantly and hCG focally. Cytotrophoblast is devoid of hCG and hPL except in choriocarcinoma, which may show focal weak staining for hCG. Immunocytochemical identification of hCG and hPL has proved helpful in clarifying the histogenesis of trophoblastic neoplasms and may also be of value in establishing their diagnosis and in determining their prognosis.     

Classification and Morphology of Gestational Trophoblastic Disease

Gestational trophoblastic disease (GTD) is a clinically and morphologically very heterogeneous group of interrelated lesions, characterised by abnormal growth of the different types of trophoblastic cells, sometimes associated with villous dysmaturity. The management and follow up of the patients and risk calculation for persistent GTD is mainly based on histopathologic diagnosis. The morphologic and differential diagnostic criteria of the villous forms of GTD (complete, partial and invasive hydatidiform moles) are summarised in the paper as well as ancillary techniques for correct diagnoses. Exaggerated placental sites (EPS) and placental site nodules (PSN) represent benign lesions, derived from the intermediate trophoblast and their characteristics are given. The concept of atypical PSN as a recently defined lesion is discussed. Gestational choriocarcinoma (CC), placental site trophoblastic tumor (PSTT) and the epitheloid trophoblastic tumor (ETT) represent tumorous forms of GTD, also termed as gestational trophoblastic tumors (GTT). Their morphologic criteria and clues for differential diagnosis are given, including the discussion about the transition from one lesion into another.     

Extrauterine choriocarcinoma of the greater omentum after tubal pregnancy: case report

Extrauterine choriocarcinoma is a rare form of gestational trophoblastic tumor. Extrauterine choriocarcinoma of the greater omentum is extremely rare in the literature. A 24-year-old female with irregular vaginal bleeding, mimicking as ectopic pregnancy, underwent emergency exploratory laparotomy and local excision of the greater omentum mass. The serum beta-human chorionic gonadotropin level decreased rapidly after operation; however, it rose up again before long. Pathology showed choriocarcinoma in the greater omentum. No evidence showed lesions on uterus. No other metastasis was found. Multiple courses of combined chemotherapy were effective for this case. Surgical excision and combined chemotherapy were effective for extrauterine choriocarcinoma of the greater omentum.     

In vivo and in vitro studies on the production of placental proteins (human chorionic gonadotropin, human placental lactogen, and pregnancy-specific beta 1-glycoprotein) in an adrenal choriocarcinoma

The ectopic production of placental proteins (human chorionic gonadotropin [hCG], human placental lactogen, and pregnancy-specific beta 1-glycoprotein) by an adrenal choriocarcinoma was investigated experimentally in vivo and in vitro. By an immunohistochemical method, the choriocarcinoma tissues obtained from the right adrenalectomy were found to react with hCG, human placental lactogen, and pregnancy-specific beta 1-glycoprotein antibodies. The concentrations of hCG-beta, human placental lactogen, and pregnancy-specific beta 1-glycoprotein in the tumor fluid were 1480, 100, and 47 ng/mL, respectively. On incubation of the tumor slices in vitro, the concentration of hCG-beta in the incubation medium increased markedly with time. Serial sections of the removed uterus and right ovary did not reveal any primary trophoblastic lesions. The present tumor responded well to double chemotherapy with actinomycin D and methotrexate, resulting in a decrease of the level of serum hCG-beta to less than 10 ng/mL after four courses of the chemotherapy.     

Hyperglycosylated hCG in gestational implantation and in choriocarcinoma and testicular germ cell malignancy tumorigenesis

OBJECTIVE: Hyperglycosylated human chorionic gonadotropin (hCG-H) is a carbohydrate variant of hCG with double-sized oligosaccharide side chains. While hCG-H is produced exclusively by stem cytotrophoblast cells in gestational choriocarcinoma, by pregnancy cytotrophoblast at implantation and by the cytotrophoblast produced in testicular malignancies, regular hCG is produced only by differentiated syncytiotrophoblast cells. STUDY DESIGN: hCG-H was measured using the Nichols Advantage hCG-H assay (Nichols Institute Diagnostics, San Clemente, California). RESULTS: hCG-H has a function separate from regular hCG. hCG-H, but not regular hCG, acts in vivo and in vitro to promote invasion, whether invasion through membranes or tumor formation. Invasion or tumorigenesis is completely blocked by administration of specific antibody to hCG-H. The same hCG-H-modulated invasion mechanisms are observed in early pregnancy, gestational choriocarcinoma and testicular cancers. CONCLUSION: hCG-H is a cytokinelike molecule, produced by cells different from those that make regular hCG and having a completely separate function. It appears to be the modulator of invasion as in implantation of pregnancy, gestational choriocarcinoma and testicular cancer malignancy.     

Outcome of Pregnancies Occurring before Completion of Human Chorionic Gonadotropin Follow-Up in Patients with Persistent Gestational Trophoblastic Tumor

OBJECTIVE: To determine the outcome of pregnancies occurring before completion of human chorionic gonadotropin follow-up in patients treated with chemotherapy for gestational trophoblastic tumor. METHODS: Retrospective record review of patients with gestational trophoblastic tumor who conceived before standard hCG follow-up was completed during 1973-1998. RESULTS: Forty-three patients treated for gestational trophoblastic tumors conceived before human chorionic gonadotropin follow-up was completed. The antecedent pregnancy was complete mole in 31 (72.1%) and partial mole in 12 (27. 9%) patients. Of the 43 patients, 39 (90.7%) had stage I, 1 had stage II, and 3 had stage III disease. The mean interval from human chorionic gonadotropin remission to new pregnancy was 6.3 months (range 1-11 months). Ten patients underwent elective termination and four patients were lost to follow-up. Of the remaining 29 patients, 22 (75.9%) had term live births, 3 (10.3%) had preterm delivery, 3 had spontaneous abortion, and 1 (3.5%) had a repeat mole. Two cases of fetal anomalies were detected; one was inherited polydactyly and the other was hydronephrosis. One patient developed choriocarcinoma with lung involvement and underwent cesarean section at 28 weeks; a normal fetus was delivered and no choriocarcinoma was detected in the placenta. CONCLUSION: Pregnancies occurring in patients treated for gestational trophoblastic tumor before standard human chorionic gonadotropin follow-up is completed may continue under close clinical surveillance since the majority have a favorable outcome. However, patients should also be advised of the low but important risk of delayed diagnosis in case tumor relapse develops during early subsequent pregnancy.     

Frequent expression of beta-human chorionic gonadotropin (beta-hCG) in squamous cell carcinoma of the cervix.

Human chorionic gonadotropin (beta-hCG) has been detected within tissue homogenates, culture fluid, and sera of patients with squamous cell carcinoma of the cervix. Studies regarding in vivo localization of beta-hCG in squamous cell carcinoma of the cervix are scant and conflicting. Cervical samplings (biopsy and/or curettage specimens) of 63 cases of poorly differentiated invasive squamous cell carcinoma of the cervix were initially stained by the immunoperoxidase technique for the presence of beta-hCG and human placental lactogen (hPL). Based on beta-hCG reactivity, patients were divided into beta-hCG-positive and beta-hCG-negative groups. Thirty-three of the 63 (52%) cases showed localization of beta-hCG in tumor cells. Subsequent specimens of patients, who underwent surgical treatment, were likewise examined for beta-hCG reactivity. These surgical specimens showed focal beta-hCG reactivity in the beta-hCG-positive group only. The beta-hCG reactivity was seen in both high-grade SIL (CIN III), invasive squamous cell carcinoma, and its metastases. The focal beta-hCG reactivity was predominantly confined to the peripheral tumor cells at the stromal-epithelial interface in noninvasive and invasive lesions. Intensity of immunostaining was moderate to strong. The beta-hCG staining was observed in different cancer stages and in various age groups. No hPL reactivity was seen in any cases. Poorly differentiated squamous cell carcinoma of uterine cervix showing immunoreactivity for beta-hCG should be distinguished from choriocarcinoma and other trophoblastic tumors.     

Estrogen and progesterone receptors and telomerase enzyme immunohistochemical detection in gestational trophoblastic tumors

The purpose of this study is to evaluate the immunohistochemical detection of telomerase enzyme and estrogen receptor (ER) and progesterone receptor (PGR) in gestational trophoblastic neoplasia (GTN) and its clinical significance. Formalin-fixed paraffin blocks for 30 patients (24 with molar pregnancy, 3 with choriocarcinoma, and 3 with placental site trophoblastic tumor) as cases and six products of conception samples from patients with incomplete abortion as controls were included in the study. Immunohistochemical detection of the telomerase catalytic protein and ER and PGR was carried out using streptavidin-biotin-peroxidase method. All control tissues were negative for telomerase and ER expression, while five of six were PGR positive. Significant positive telomerase expression was detected in all gestational trophoblastic tumors (three of six partial moles, 12 of 18 complete moles, three of three choriocarcinomas, and two of three placental site trophoblastic tumors). Nine of 24 molar pregnancies were followed by GTN. Molar pregnancies followed by GTN were associated with higher serum beta-hCG (human chorionic gonadotrophic hormone), larger uterine size for gestational age, negative ER expression, negative PGR expression, and positive telomerase expression. All patients with molar pregnancy with negative telomerase expression (9 of 24) showed spontaneous regression after evacuation. Positive telomerase expression and its immunohistochemical detection are associated with the development of GTN. Negative telomerase expression is highly predictive of postmolar spontaneous regression. Patients with molar pregnancies with negative telomerase expression can be saved the long-term follow-up. ER and PGR expression do not show a significantly different pattern in molar tissues, while negative expression is associated with developing GTN. Cautions on the use of postmolar hormonal contraception may be unjustified.     

Measurement of CA-125 in trophoblastic disease

OBJECTIVES: Physicians treating hydatidiform mole are still seeking means of identifying those patients who will require chemotherapy. The standard accepted method is to follow human chorionic gonadotropin levels but CA-125 measurement has been suggested as a supplement that may be clinically useful. This study was undertaken to validate or refute the one previous study that addresses this issue. CA-125 was measured at the time of hydatidiform mole evacuation to determine (1) whether it would predict the need for chemotherapy and (2) whether it correlated with human chorionic gonadotropin and tumor load in following patients with hydatidiform mole and metastatic gestational trophoblastic disease. PATIENTS AND METHODS: CA-125 was measured in serial weekly samples selected from diagnostic groups of patients with trophoblastic disease. Sixteen patients had hydatidiform mole with spontaneous resolution, fourteen had nonmetastatic gestational trophoblastic tumor, and four had low-risk metastatic disease. Six patients had high-risk metastatic disease. Ten patients had partial hydatidiform mole and one of these required chemotherapy. One patient had primary ovarian choriocarcinoma and three had placental site tumor. RESULTS: The mean preevacuation CA-125 among the 15 patients with complete hydatidiform mole was 40.9 U/ml: 52.5 U/ml for 5 patients who required chemotherapy and 36.2 U/ml for 10 patients who did not require chemotherapy. There was no statistical difference between these values. There was no correlation of CA-125 with hCG. Frequently CA-125 became negative when hCG was still elevated. Among six patients with high-risk disease, CA-125 was elevated in four but in all six patients hCG remained elevated when CA-125 became negative. In nine patients with partial hydatidiform mole CA-125 was elevated prior to mole evacuation and then became negative. The patient with a tetraploid conceptus who required chemotherapy had negative CA-125. With placental site tumor CA-125 was negative, but it was elevated with ovarian choriocarcinoma. CONCLUSION: CA-125 levels do not provide reliable information in the management of patients with gestational trophoblastic disease.     

A plea for the creation of trophoblastic disease reference centers in France

Gestational trophoblastic diseases include partial and complete molar pregnancies together with trophoblastic tumors, namely invasive mole, choriocarcinoma and placental site trophoblastic tumor. Important advances continue to occur in both our understanding and management of these diseases. The general guidelines we display here are intended to standardize the essential current management of trophoblastic diseases and justify the creation of a reference center in France. The goal of such a center is to optimize the treatment of patients. The center can help in drawing and interpreting the human chorionic gonadotrophin regression curve and give the multidisciplinary current recommendations to the physician in charge of the patient. The aim is to diagnose and treat as soon as possible the malignant forms of the disease as the interval between the previous pregnancy and the initiation of treatment is a major prognostic factor.     

Metastatic Cerebral Choriocarcinoma Coexistent with a Viable Pregnancy

Gestational choriocarcinoma associated with a viable pregnancy is extremely rare, and such choriocarcinoma with metastases presenting during the pregnancy is even more exceptional. Metastases from this tumor may present in a variety of ways depending on the site of the metastatic lesion, and can be fatal before choriocarcinoma is even suspected. We describe a 32-year-old primigravida presenting at 31 weeks gestation with a grand mal seizure due to cerebral metastases secondary to gestational choriocarcinoma who was subsequently successfully treated with chemotherapy. To our knowledge this is the first reported case of choriocarcinoma presenting with signs due to cerebral metastases during pregnancy where both the mother and child survived. This paper emphasizes the need to consider metastatic choriocarcinoma in any gravid female who presents with unusual neurological signs because of the life-threatening nature of this potentially curable disease.     

The role of hysterotomy in the management of gestational trophoblastic neoplasia

The management of late gestational trophoblastic disease recurrence is challenging. We present a case of a 16-year-old woman who was diagnosed with a gestational trophoblastic neoplasia 14 months after her hydatidiform mole pregnancy. A staging was performed revealing only an intramural lesion, which resembled a myoma, in the fundus of the uterus. Despite two course of methotrexate, the human chorionic gonadotropin (hCG) level increased slowly. The presentation was highly suggestive for a placental site trophoblastic tumor. A local resection of the tumor by hysterotomy was performed. Pathologic examination revealed a choriocarcinoma with tumor-free surgical margins. Subsequently, the patient received three cycles of EMA-CO (etoposide, methotrexate, actinomycin, cyclophosphamide, and vincristine). At present, 89 months after the hysterotomy, the patient is well, with no sings of recurrence. This report illustrates that it is mandatory to have a histologic diagnosis of chemoresistant gestational trophoblastic neoplasia before performing definitive surgery.     

Human chorionic gonadotropin free beta-subunit measurement as a marker of placental site trophoblastic tumors

OBJECTIVE: To evaluate the utility of free human chorionic gonadotropin beta-subunit (hCGbeta) proportion of total hCG measurement to distinguish placental site trophoblastic tumor (PSTT) from more common forms of gestational trophoblastic disease (GTD). STUDY DESIGN: Serum samples collected from PSTT, persistent trophoblastic disease (PTD) and choriocarcinoma patients were used for retrospective analysis of free hCGbeta-subunit. Results were reported as a percentage of total hCG using our in-house competitive radioimmunoassay. RESULTS: The percentage of free hCGbeta was significantly greater in serum from 18 PSTT patients, yielding a median value of 45.5% than in a combined GTD group of 49 PTD and 12 choriocarcinoma patients. Receiver operating characteristic analysis confirms that the percentage free hCGbeta distinguishes PSTT from GTD patients. Choriocarcinoma patients had significantly higher hCGbeta measurements than PTD patients and were not well distinguished from PSTT patients. CONCLUSION: Our findings show that an elevated proportion of free hCGbeta-subunit is a helpful but not definitive test to discriminate PSTT from other forms of GTD.     

Myometrial and placental artery reactivity alone cannot explain reduced placental perfusion in pre-eclampsia and intrauterine growth restriction

Objectives (1) To investigate a possible association between myometrial and placental artery vasoreactivity and perfusion at the basal and chorionic plates, respectively. (2) To confirm that myometrial arteries from women with pre-eclampsia and intrauterine growth restriction exhibit an attenuated endothelium-dependent vasodilatory response.
Methods Women with normal pregnancy, pre-eclampsia and intrauterine growth restriction had a magnetic resonance scan to assess placental perfusion using a technique called intravoxel incoherent motion . At delivery, myometrial and chorionic plate placental arteries were assessed on a wire myograph. Vessels were pre-constricted with the thromboxane mimetic U46619 and dilated with incremental doses of bradykinin.
Results Pre-constricted myometrial arteries from women with pre-eclampsia or intrauterine growth restriction exhibited an attenuated vasodilatory response to bradykinin, compared with normal pregnancy (   P < 0.0001  ). Pre-constricted placental arteries exhibited a minimal vasodilatory response in all three groups of women (   P = 0.10  ). Maximal constrictor and vasodilatory responses of myometrial arteries were not associated with the perfusing fraction at the basal plate. Maximal constrictor and vasodilatory responses of chorionic plate placental arteries were not associated with the perfusing fraction at the chorionic plate.
Conclusion We confirm that myometrial arteries from women with pre-eclampsia or intrauterine growth restriction exhibit an attenuated endothelium-dependent vasodilatory response. Apart from vasoreactivity of small arteries, other factors may be involved in the control of placental perfusion.     

Placental site trophoblastic tumor: with features between an exaggerated placental site reaction and a placental site trophoblastic tumor

Chorionic villi, whose presence in cases of trophoblastic disease is normally used to exclude both a choriocarcinoma and placental site trophoblastic tumor (PSTT), were present in the initial uterine curettage specimen of a trophoblastic tumor. The lesion shared morphologic features of both an exaggerated placental site reaction and a PSTT. There was infiltration of the posterior wall of the uterus by small clusters and isolated cells which had a prominent affinity for vessels and resembled a usual placental bed reaction. There was, however, deep involvement of myometrium with extension to the cervix, and the condition persisted for 5 months after uterine evacuation. Because different treatment is entailed, identification of this lesion as a tumor of nonvillous trophoblast is also of great importance in a region where the more usual forms of trophoblastic disease represent a declining but not infrequent event. When products of gestation are examined, the possibility of a PSTT should be considered and the clinician alerted if there is a suggestion of excessive intermediate trophoblastic activity, regardless of the presence of chorionic villi. While this may result in the unnecessary followup of some cases, it would permit, with the aid of serial beta-hCG and HPL levels, the earlier detection of PSTTs.     

Pathology of gestational trophoblastic diseases

Gestational trophoblastic disease (GTD) is a heterogeneous group of diseases. This used to include partial and complete hydatidiform moles, invasive mole, choriocarcinoma and placental site trophoblastic tumour. In recent years, new entities, including epithelioid trophoblastic tumour, have been added to this family. Non-neoplastic and neoplastic lesions derived from implantation site and chorion intermediate trophoblast have been gaining attention in the literature. New markers for trophoblasts have been identified facilitating histological diagnosis in cases with unusual clinical or pathological features. It is worth noting that histological distinction between hydropic abortion and partial mole and between complete and partial moles, especially at early gestational age, may be difficult. It may not be possible to predict progress of the heterogeneous group of GTD from histopathological features, except probably in placental site trophoblastic tumour. Alternative biological markers may be explored for better patient management.