Gestational trophoblastic diseases: 3. Human chorionic gonadotropin-free beta-subunit, a reliable marker of placental site trophoblastic tumors

OBJECTIVES: Placental site trophoblastic tumor (PSTT) commonly presents with low and variable concentration of hCG immunoreactivity in serum which can be difficult to differentiate from early stage choriocarcinoma/gestational trophoblastic neoplasm (GTN) or quiescent gestational trophoblastic disease (quiescent GTD). Nontrophoblastic malignancies such as germ cell tumors or other tumors secreting low hCG must also be considered in the differential diagnosis. Because treatments for these conditions are different, a means of differentiating PSTT from other diagnoses is important. We investigate the usefulness of hCG-free beta-subunit to make this discrimination. METHODS: Data collected on cases referred to the USA hCG Reference Service for consultation served as a basis for this retrospective analysis. There were 13 cases with histology proven PSTT and 12 with nontrophoblastic malignancy. hCG-free beta-subunit was measured by immunoassay and reported as a proportion of total hCG (hCG-free beta-subunit(%)). hCG-free beta-subunit(%) results were determined for all histologically proven cases of PSTT and for the nontrophoblastic malignancies. Comparisons of hCG-free beta-subunit(%) were made and compared with those of the 82 choriocarcinoma/GTN cases and 69 quiescent GTD cases. The accuracy of hCG-free beta-subunit(%) to discriminate these malignancies was analyzed by investigating the areas under receiver-operating characteristics curve +/- standard error. RESULTS: hCG-free beta-subunit(%) was the predominant hCG form in cases of PSTT (mean +/- standard deviation, 60 +/- 19%) and nontrophoblastic malignancies (91 +/- 11%), thus discriminating these diagnoses from choriocarcinoma/GTN (9.3 +/- 9.2%) and from quiescent GTD (5.4 +/- 7.8%). The cutoff of >35% free beta-subunit is proposed. At this cutoff, 100% detection at 0% false-positive is achieved. The accuracy of hCG-free beta-subunit(%) for this discrimination is 100 +/- 0%. At a proposed cutoff of >80%, the free beta-subunit test will also distinguish PSTT from nontrophoblastic malignancy, with 77% detection at 23% false-positive or an accuracy of 92 +/- 3.2%. CONCLUSION: Measurement of the proportion hCG-free beta-subunit(%) was found to be useful in the diagnosis of PSTT using proposed cutoff values of >35% and >80%. While this finding needs to be confirmed by larger studies, it would be reasonable to measure hCG-free beta-subunit(%) whenever the diagnosis of PSTT is considered.     

Blood test for placental site trophoblastic tumor and nontrophoblastic malignancy for evaluating patients with low positive human chorionic gonadotropin results

OBJECTIVE: To examine utility of measurement of proportions of free beta-subunit of human chorionic gonadotropin (hCG) in diagnosis of placental site trophoblastic tumor (PSTT) and nontrophoblastic neoplasm in patients with persistent low hCG levels and patients with history of gestational trophoblastic diseases. STUDY DESIGN: The USA hCG Reference Service measured proportions of free beta-subunit in 128 cases, 45 with active invasive trophoblastic disease and 83 questionable cases with persistent low hCG levels, with or without history of gestational trophoblastic disease (GTD). RESULTS: High proportions of free beta-subunit (> 30% of total hCG) were identified in 18 of 128 cases, all suspected of having PSTT or nontrophoblastic neoplasm, which was reported to referring physicians. Within 2 months of testing, hysterectomy or tumor biopsy led to histologic proof of PSTT in 13 of the 18 cases and biopsy led to proof of nontrophoblastic neoplasm in 5 of the 18 cases. CONCLUSION: We confirm use of proportion of free beta-subunit (> 30%) as a seemingly absolute test for identifying PSTT and nontrophoblastic neoplasms. It should be used to identify and diagnose these malignancies in women presenting with persistent low hCG levels outside of pregnancy and in secondary evaluation of patients with a history of GTDs.     

Gestational trophoblastic diseases: 2. Hyperglycosylated hCG as a reliable marker of active neoplasia

OBJECTIVES: To determine whether circulating hyperglycosylated human chorionic gonadotropin (hCG-H), a promoter of choriocarcinoma growth and tumorigenesis, is a reliable marker of active gestational trophoblastic neoplasia (GTN) or choriocarcinoma, and whether hCG-H can consistently discriminate quiescent gestational trophoblastic disease (GTD) from neoplasia. METHODS: Patients were those referred to the USA hCG Reference Service for consultation. These included a total of 82 women with GTN, including 30 with histologic choriocarcinoma. They were compared with 26 patients with resolving hydatidiform mole and 69 with quiescent GTD (persistent positive low value of real hCG but no clinical evidence of disease). All were tested for total hCG and hCG-H. hCG-H was calculated as the percentage of total hCG (hCG-H(%)). RESULTS: We compared the utility of total hCG and hCG-H(%) in detecting active GTN and quiescent GTD. There was no significant difference when measuring total hCG (includes regular and hyperglycosylated hCG), between women with quiescent GTD and self-resolving hydatidiform mole compared to choriocarcinoma/GTN cases (P > 0.05 and P > 0.05). In contrast, hCG-H(%) was significantly higher in choriocarcinoma/GTN cases (P < 0.000001, and P < 0.000001). The usefulness of hCG and hCG-H(%) testing was assessed for discriminating between the 69 quiescent GTD cases, which required no therapy, and choriocarcinoma/GTN which need treatment. While hCG would detect 62% and 24% of malignancies at a 5% false positive rate, hCG-H(%) would detect 100% and 84% of malignancies at this same false positive rate. Follow-up data were received and repeat consultations were performed in 23 cases in which active disease was subsequently demonstrated. In 12 of 23 cases, hCG-H(%) results were able to first identify active disease 0.5 to 11 months prior to rapidly rising hCG or detection of clinically active neoplasia. In the remaining 11 cases, hCG-H(%) active disease appeared at the same time as rising hCG or demonstrable clinical tumor. DISCUSSION AND CONCLUSION: hCG-H(%) appears to reliably identify active trophoblastic malignancy. It is a 100% sensitive marker for discriminating quiescent GTD from active GTN/choriocarcinoma. It is also a marker for the early detection of new or recurrent GTN/choriocarcinoma. The data presented appear sufficient to encourage the adoption of hCG-H as a tumor marker in trophoblastic disease. Further studies are now urgently required to confirm and extend our findings.     

Placental site trophoblastic tumor--a challenging rare entity

Placental site trophoblastic tumor (PSTT) is a challenging rare variant of gestational trophoblastic disease (GTD) with variable characteristics. Historically, it was first described in 1895 and was considered a benign lesion until Scully and Young recognized its malignant potential in 1981. Current knowledge related to PSTT is largely based on the experience of handling this disease in established trophoblastic disease centers and on the experience of authors who reported small series or singular cases. In contrast to other forms of GTD, it arises from the implantation-site intermediate trophoblast, produces less beta-hCG and is less sensitive to chemotherapy. More than half of the patients present with disease confined to the uterus, whereas the remainder present with disease extension beyond the uterus. Because of the relative insensitivity to chemotherapy, simple hysterectomy is the mainstay of treatment. While the outcome of patients with disease confined to the uterus is usually excellent, most patients with disease extension beyond the uterus experience progression of disease and die despite surgery and aggressive chemotherapy. Other important adverse prognostic factors are interval from antecedent pregnancy > 2 years, age > 40 years and mitotic count > 5 mf/10 HPF Although the ideal chemotherapy regimen for PSTT has yet not been established, it seems that the EP/EMA regimen is the most effective first-line chemotherapy available to date for metastatic and relapsing PSTT. Although PSTT produces less hCG than choriocarcinoma, beta-hCG is still the best available serum marker to follow the disease and treatment course of PSTT.     

Management of gestational trophoblastic disease and other cases with low serum levels of human chorionic gonadotropin

Recent publications show that the measurements of particular human chorionic gonadotropin (hCG) variants are extremely beneficial in the diagnosis, monitoring and treatment of gestational trophoblastic disease (GTD). Here we review the possible sources of hCG and the use of commercial tests in the optimal management of GTD, quiescent GTD,false positive hCG results, placental site trophoblastic tumor (PSTT) detection, nontrophoblastic neoplasms and pituitary hCG. Hyperglycosylated hCG (hCG-H) measurements are ideal for discriminating active (invasive) from inactive (quiescent or benign) disease. hCG-H testing is also more sensitive than regular hCG in detecting recurrent or persistent disease. After excluding false positive hCG results, and in the absence of any radiographic evidence of tumor, hCG-H should be measured before starting chemotherapy or surgery in women presenting with low hCG (<1,000 mIU/mL) with or without a history of GTD. The hCG free beta assay is an invaluable test in discriminating PSTT from other GTDs, thereby aiding the determination of appropriate treatment options.     

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.     

Gestational trophoblastic diseases: 4. Presentation with persistent low positive human chorionic gonadotropin test results

OBJECTIVES: A high proportion of women with persistent low levels of hCG, in the absence of pregnancy or any evidence of tumor, have received chemotherapy and hysterectomy for assumed malignancy. Such chemotherapy and surgery were ineffective and unwarranted. This study identifies the causes of persistent low level of hCG and provides guidelines for the management of these patients, preventing unnecessary treatment in the future. METHODS: The USA hCG Reference Service has consulted on 170 women with low levels of hCG persisting for 3 months or longer. Serum total hCG was measured in the Diagnostic Products Corporation (DPC) Immulite assay and hyperglycosylated hCG in the Nichols Advantage test. RESULTS: Among these 170 patients, the average persistent hCG result was 102 +/- 152 mIU/ml, with a range of 6.1-900 mIU/ml. Thirteen (7.6%) of the 170 patients had true malignancy, 5 had placental site trophoblastic tumor, 3 had other gestational trophoblastic neoplasms (GTN), and 5 had non-trophoblastic malignancies. The remaining 157 patients had false-positive hCG, quiescent gestational trophoblastic disease (quiescent GTD), or pituitary hCG (hCG of pituitary origin). Of 71 patients with false-positive hCG, 47 patients received chemotherapy and 9 had surgery that had no effect on the level of hCG. Five of these patients with false-positive hCG were being monitored for hydatidiform mole or GTN. The majority of these cases were first investigated following an incidental pregnancy test. Of 69 patients who had quiescent GTD, 41 received chemotherapy and 9 underwent hysterectomy. All these therapies were unnecessary and ineffective. While 21 patients with quiescent GTD followed incidental pregnancy tests, the majority were discovered while monitoring patients after treatment for hydatidiform mole or GTN/choriocarcinoma (n = 48). Seventeen cases of pituitary hCG were found among those women who were peri- or post-menopause. Two patients also received chemotherapy for assumed malignancy which was not present. CONCLUSION: Clinicians frequently assume that an elevated hCG implies that a patient is pregnant or has GTD or recurrent GTN, even when apart from the pregnancy test, no clinical evidence was found to support such a diagnosis. In most of these cases of persistent low hCG etiologies, all therapies were found unnecessary and ineffective. Guidelines are proposed for managing these patients. It is essential to demonstrate a malignancy clinically and with readily available biochemical tests before initiating therapy. This applies whether the patient is identified by an incidental pregnancy test or is actively being monitored for gestational trophoblastic disease.     

Change in human chorionic gonadotropin in gestational trophoblastic disease observed during the course of chemotherapy.

This study investigates the physicochemical characteristics of human chorionic gonadotropin (hCG) in gestational trophoblastic disease (GTD), with special reference to the clinical course of chemotherapy and prognosis. In gel high performance liquid chromatography (HPLC), the hCG molecules from normal pregnancy and from the hydatidiform mole had the same molecular form as standard purified hCG, whereas hCG from choriocarcinoma was inconsistent in molecular form, containing molecules which are smaller, the same or larger than those of standard purified hCG. In two fatal choriocarcinoma patients, large hCG and large hCG alpha were found in the urine samples collected within one month prior to death. In a chromatofocusing study, the chromatofocusing pattern of hCG from GTD was acidic and similar to that of early pregnancy. The chromatofocusing patterns did not alter or were altered only slightly during the course of chemotherapy. In a Concanavalin A-Sepharose (Con A) chromatography study, the Con A binding shifted from low to high binding in patients with GTD who were responsive to chemotherapy. In summary, the molecular form, electric charge and Con A binding of hydatidiform mole hCG are similar to those of early pregnancy hCG and standard purified hCG, whereas the molecular form and Con A binding of choriocarcinoma are different from those of early pregnancy hCG and standard purified hCG. The presence of smaller or larger molecular forms of hCG may be an ominous sign, whereas the presence of high Con A binding may be a favorable sign. The chromatofocusing pattern seems to be unrelated to the clinical course of chemotherapy.     

Choriocarcinoma and gestational trophoblastic disease

Gestational trophoblastic disease (GTD) encompasses a unique group of uncommon but interrelated conditions derived from placental trophoblasts. For the purposes of discussion GTD is the appropriate collective name for hydatidiform mole, whereas the term gestational trophoblastic neoplasia (GTN) is reserved for cases with persistent human chorionic gonadotropin (hCG) titer elevation after evacuation of hydatidiform mole, metastatic disease, or choriocarcinoma. Although the pathology and clinical behavior of CM and PM are different, the initial management of both conditions is surgical evacuation by suction curettage, determination of the baseline, and follow-up with (hCG) titers. There are guidelines for risk-factor scoring and a staging system that classifies untreated patients into distinct prognostic categories so that treatment outcomes can be objectively compared. The rates of GTN and choriocarcinoma are decreasing and survival has dramatically improved.     

Placental site trophoblastic tumour

Placental site trophoblastic tumour (PSTT) is a very rare and unique form of gestational trophoblastic disease (GTD). This tumour represents a neoplastic transformation of intermediate trophoblastic cells that normally play a critical role in implantation. PSTT can occur after a normal pregnancy, abortion, term delivery, ectopic pregnancy or molar pregnancy. It displays a wide clinical spectrum, and when metastatic, can be difficult to control even with surgery and chemotherapy. Unlike other forms of GTD, PSTT is characterized by low beta-hCG levels because it is a neoplastic proliferation of intermediate trophoblastic cells. Expression, however, of human placental lactogen (hPL) is increased on histologic section as well as in the serum. The most common presenting symptoms of PSTT are vaginal bleeding and amenorrhoea. Diagnosis is confirmed by dilatation and curettage (D and E) and hysterectomy but meticulous evaluation of metastasis is mandatory. Most cases are confined to the uterus but pelvic involvement, lung and other organ metastasis has been reported. Unlike other forms of GTD, the WHO prognostic score is of little help. For the PSTT patient, surgery is the primary treatment of choice. For patients desiring future childbearing, D and C and adjuvant chemotherapy is an option. Because these tumours tend to be less sensitive than other types of GTD to chemotherapy, the most successful regimen to date has been with EMA/CO or EMA/EP. Good prognosis is anticipated in cases localized to the uterus, and when the interval between antecedent pregnancy and treatment is less than 2 years. In cases with distant metastasis or delayed treatment, the outcome is dismal.Advances in chemotherapeutic regimens have improved clinical reponse in metastatic disease.     

Management of Chemoresistant and Quiescent Gestational Trophoblastic Disease

Gestational trophoblastic neoplasia (GTN) is highly chemosensitive and has a high cure rate. Since the introduction of chemotherapy, reliable measurement of human chorionic gonadotropin (hCG) levels, and individualised risk-based therapy into the management of GTN, almost all low-risk and more than 80 % of high-risk GTN cases are curable. However, approximately 25 % of high-risk GTN developed resistance to chemotherapy or relapsed after completion of initial therapy, which often necessitate salvage combination chemotherapy. On the other end of the spectrum, a proportion of patients with gestational trophoblastic disease (GTD) have persistently low levels of hCG, without clinical or radiological evidence of disease, a condition called quiescent GTD. Recently, measurement of hyperglycosylated hCG has been proposed for the management of patients with quiescent GTD. Although representing a small proportion of GTD cases, the management of patients with chemoresistant and quiescent GTD often poses challenges to medical practitioners.     

Molecular heterogeneity of hCG in urine of the patients with trophoblastic diseases]

In addition to whole hCG, hCG beta-related molecular species are also present in the serum and urine of patients with trophoblastic diseases. We simultaneously measured whole hCG, free hCG beta and beta-core fragment in the serum and urine of patients with hydatidiform mole and choriocarcinoma by the highly specific and sensitive sandwich enzyme-immunoassay (EIA) systems using two kinds of antibodies. During the clinical courses of patients, although the whole hCG levels in serum and urine were closely correlated, the concentrations in the serum were almost twice as high as those in the urine. The free hCG beta levels were also closely correlated in serum and urine, but the concentrations of free hCG beta were extremely low as compared with those of whole hCG. Furthermore, free hCG beta/whole hCG ratios were significantly higher in choriocarcinoma patients than in hydatidiform mole patients. While whole hCG and free hCG beta were contained in both serum and urine, the beta-core fragment could be detected only in the urine of the patients. The relative contribution of the beta-core fragment to the total urinary hCG beta-immunoactivity accounted for about 40% in hydatidiform mole and about 70% in choriocarcinoma. We conclude that whole hCG should be measured in the serum rather than in the urine as a tumor marker for trophoblastic diseases, and suggest that the ratios of whole hCG, free hCG beta and beta-core fragment to each other may be useful indices to employ in the differential diagnosis of trophoblastic diseases.     

Placental site trophoblastic tumor with an ovarian metastasis

Placental site trophoblastic tumors (PSTT) are the rarest form of gestational trophoblastic disease (GTD). The clinical management of PSTT differs from the other forms of GTD as surgery plays a more important role. The most common metastatic sites are the lung, liver, and vagina while spread to the adnexa is relatively unusual. We describe a case of a 35-year-old woman presenting with PSTT and ovarian metastasis who was successfully treated with radical hysterectomy, bilateral oophorectomy, pelvic lymph node dissection, and postoperative chemotherapy. The case highlights the possibility of ovarian metastases despite normal preoperative imaging and confirms the value of multidisciplinary management of this rare illness.     

Galectin-1 and galectin-3 in the trophoblast of the gestational trophoblastic disease

While the presence and distribution of galectin-1 and galectin-3 in different normal trophoblast cell populations is known, no information is available regarding their occurrence in malignant trophoblast of gestational trophoblastic disease (GTD). Galectins-1 and -3 have, however, been implicated in malignancies of other tissues. Immunoreactivity for these galectins in the transformed trophoblast of invasive mole (n = 8), choriocarcinoma (n = 7) and one case of placental site trophoblastic tumor (PSTT) was compared to that of the invasive trophoblast of the normal first trimester of pregnancy implantation sites (n = 9). A large proportion of the transformed trophoblast cells of all GTD studied were positive for galectin-1 and galectin-3. Immunoreactivity was scored semiquantitatively to include both the prevalence among the trophoblast cells and the intensity of staining. Immunoreactivity for both galectin-1 and galectin-3 in gestational trophoblastic disease is increased (significant differences at p < 0.05, Mann-Whitney Rank Sum Test). This finding may suggest a possible implication of galectins-1 and -3 in the invasiveness of the transformed trophoblastic cell, although the exact physiological significance of this finding remains to be determined.     

Morphological and immunohistochemical study on specimens of trophoblastic diseases in which the presence of a villous formation could not be established

The histopathological discrimination between malignant trophoblastic diseases and benign trophoblastic diseases depends on the presence or absence of a villous structure. However, molar extravillous trophoblasts and cells in some placental site trophoblastic tumors (PSTT) of a benign nature, lack a villous structure. We therefore observed the morphology of trophoblastic cells which do not constitute a villous structure, including choriocarcinoma cells, and analyzed the location of placental proteins in these cells immunohistochemically. The results were as follows: 1. Molar extravillous trophoblasts were composed of large mononuclear cells and multinuclear cells. Most of them were positive for hPL and negative for hCG and SP1. 2. Choriocarcinoma consisted of cytotrophoblast-like cells, syncytiotrophoblast-like cells, large mononuclear cells and multinuclear cells resembling large mononuclear cells. HCG was noted in syncytiotrophoblast-like cells and large mononuclear cells, while hPL and SP1 were found only in syncytiotrophoblast-like cells. 3. PSTT was made up of large mononuclear cells and multinuclear cells which contained abundant hPL and very little hCG and SP1 or none at all. Molar extravillous trophoblasts were clearly distinguishable from choriocarcinoma cells in terms of their morphology and the location of placental proteins. In contrast, it seemed difficult to distinguish cells of PSTT from molar extravillous trophoblasts on a cell level.     

Japanese trial for classification of gestational trophoblastic disease

OBJECTIVE: To evaluate the clinical usefulness of the Japanese Diagnostic Score to differentiate choriocarcinoma clinically without histologic findings from persistent gestational trophoblastic disease (GTD). STUDY DESIGN: We reviewed the clinical records and histologic reports on all 809 patients with persistent GTD treated with surgery and chemotherapy in Japan. There were 347 cases of choriocarcinoma and 462 cases of invasive mole with histologic confirmation. We retrospectively applied the Japanese Diagnostic Score to all patients for detection of choriocarcinoma in persistent trophoblastic disease. RESULTS: The sensitivity of the score for choriocarcinoma was 92.2%. The specificity was 93.5%. This retrospective study showed that the accuracy of this scoring system to differentiate true malignant choriocarcinoma clinically from both low risk and high risk gestational trophoblastic neoplasia without histologic findings was 92.9%. CONCLUSION: Our trial to differentiate choriocarcinoma clinically from persistent GTD without histologic findings using a unique scoring system was successful. Proper management in the early stages strongly influences the outcome of these diseases. This scoring system should be very useful in comparing the incidence and survival rate of choriocarcinoma between nations.     

Inappropriate management of women with persistent low hCG results

The USA hCG Reference Service is a consulting service with a specialized clinical laboratory aiding physicians in the interpretation of conflicting or nonrepresentative human chorionic gonadotropin (hCG) results. We have consulted on 189 cases with persistent low levels of hCG but no evidence of pregnancy or tumor. Quiescent gestational trophoblastic disease (GTD) was identified in 121 cases by the absence of invasive trophoblast antigen and nonresponse to chemotherapy (64 cases with a history of hydatidiform mole or gestational trophoblastic neoplasia (GTN) and 57 cases following antecedent pregnancy). Another 61 Reference Service cases hadfalse positive hCG, and we observed 7 cases with low levels of hCG of pituitary origin (hCG subsequently suppressed by estrogen-progesterone medication). Most disturbing is that the majority of these cases (68%) received needless therapy for assumed GTN/choriocarcinoma/placental site trophoblastic tumor before consultation with the Reference Service. One hundred twenty-eight of the 189 patients (77 of 121 with quiescent GTD, 48 of 61 withfalse positive hCG and 3 of 7 with pituitary hCG) underwent therapy ranging from single-agent chemotherapy (117 cases), to EMA-CO combination chemotherapy (etoposide, methotrexate, actinomycin D alternating with cyclophosphamide and vincristine) (16 cases), to hysterectomy and/or bilateral salpingo-oophorectomy (31 cases). False positive hCG and pituitary hCG would obviously not respond to these treatments, and no treated cases of quiescent GTD responded to chemotherapy orfully responded to hysterectomy. The continued needless treatment of patients with quiescent GTD, even after multiple publications, is entirely avoidable. Unfortunately, the number of needlessly treated cases referred to the Reference Service is increasing.     

Cytokeratin 20 as a biomarker of gestational trophoblastic disease: diagnostic and prognostic significance

OBJECTIVES: This study was designed to examine whether cytokeratin 20 (CK20) is expressed in molar pregnancies and may therefore be used in the diagnosis of gestational trophoblastic disease (GTD). The potential of CK20 expression in predicting the evolution and the prognosis of the different subtypes of GTD was also assessed. METHODS: A total of 48 samples were studied for CK20 expression by RT-PCR methodology. Among these, 24 samples were obtained by curettage of the uterine cavity of patients diagnosed with hydatidiform mole (14 complete moles and 10 partial moles), 4 samples were obtained from choriocarcinoma cell lines (2 JAR and 2 JEG), and 20 samples were of normal trophoblast (control group) obtained from patients that underwent elective termination of pregnancy. RESULTS: Expression of CK20 was identified in all the samples of complete mole (CM), all choriocarcinoma cell lines, and 50% of the patients with partial mole (PM). None of the preparations of normal trophoblastic tissue from the control group expressed the CK20. A significant difference (P < 0.00001) was found in CK20 expression between samples of patients with GTD and control samples. Comparison between CK20 expression in CMs and PMs revealed a significantly more frequent expression of CK20 in CMs (P = 0.006). More than 50% of the patients with PMs that were positive for CK20 had an invasive evolution. CONCLUSIONS: In our opinion, CK20 may assist in distinguishing between molar and normal trophoblastic tissue and may be considered a marker of GTD. In cases in which pathological classification of different subtypes of GTD is in doubt, CK20-positive expression is suggestive for a CM whereas CK20-negative is more indicative for PM.     

Twenty-five years' clinical experience with placental site trophoblastic tumors

OBJECTIVE: To describe 34 cases of placental site trophoblastic tumor (PSTT) treated at Charing Cross Hospital over 25 years. STUDY DESIGN: Between 1975 and 2001, 1,685 patients with gestational trophoblastic disease (GTD) were treated; 34 of them had PSTT (2%). The computer database clinical notes and the pathology reports were accessed to obtain data on this patient group. The data were subsequently analyzed using Excel computer software. RESULTS: The mean age of the group was 33 years (95% CI 25-41). The antecedent pregnancy was a full-term, normal one in 18 cases (53%), a molar pregnancy in 7 (21%) and a missed abortion in 5 (15%). The mean interval from the last pregnancy to diagnosis was 3.4 years (95% CI 1.9-4.9). The range of serum hCG concentrations at diagnosis was 0-58,000, 79% with levels < 1,000 and 58% < 500. hCG was raised in all with active disease. The most frequent presenting complaint was vaginal bleeding, in 27 cases (79%). At diagnosis, the disease was localized to the uterus in 15 (44%); there was pelvic involvement in 8 (24%) and lung secondaries in 10 (29%). All seven deaths were disease related (21%); all had lung secondaries and presented more than four years since the last pregnancy. Excluding the seven deaths, the primary treatment was surgery alone in 10 cases (37%) (8 hysterectomies and 2 dilatation and curettages); 4 had surgery followed by adjuvant chemotherapy; 5 had neoadjuvant chemotherapy followed by surgery; 1 had chemotherapy alone, and the disease recurred and was successfully rechallenged; and 5 had surgery between chemotherapy cycles. The most common regimens consisted of EMA/CO and EP/EMA. CONCLUSION: Risk factors for death include lung metastatic involvement (50%) and an antecedent pregnancy interval of four years or more (100%). In contrast, those with no extrapelvic disease or a pregnancy interval of less than four years had 100% survival. In two-thirds of patients with disease limited to the uterus, surgery alone was curative. The WHO scoring system for GTD did not correlate with this outcome. Patients with PSTT should be managed separately from those with other types of GTD, as the disease behavior is different.     

妊娠滋养细胞疾病/肿瘤医学专有名词汇集和解读

随着妊娠滋养细胞疾病（gestational trophoblastic disease,GTD）/妊娠滋养细胞肿瘤（gestational trophoblastic neoplasia,GTN）诊治研究的不断深入,与其相关的病因、遗传学、分子生物学及临床研究等方面的论文逐步增多,因此GTD/GTN相关专有名词的正确使用至关重要。现结合国情,从妊娠滋养层细胞、GTD的分类、GTD组织分型、葡萄胎、葡萄胎后属有关的GTD/GTN、绒毛膜癌、GTD治疗、治疗评分后分度、人绒毛膜促性腺激素（human chorionic gonadotophin,hCG）分子家族及临床问题等九个分类进行详细阐述,汇集和解读了GTD/GTN相关的专有名词,便于妇产科医师对这些专有名词的理解和使用。