Atypical placental site nodule (APSN) and association with malignant gestational trophoblastic disease; a clinicopathologic study of 21 cases. Int J Gynecol Pathol. 2015;34:152-158. [PMID: 25675185 DOI: 10.1097/pgp.0000000000000128]

Epidemiology of Gestational Trophoblastic Disease

Worldwide incidence rates of gestational trophoblastic disease (GTD) are difficult to estimate and compare due to large methodological differences within and between countries. Asia has generally reported higher incidence rates than Europe and North America, but modern reports have demonstrated a temporal decrease of GTD incidence rates in Asia and an increase in some European countries and North America. The main risk factors for hydatidiform mole are maternal age and previous molar events. Future studies on the epidemiology of GTD should include gestational trophoblastic neoplasia and international collaborative studies on this rare disease should be encouraged.

Future Directions for Gestational Trophoblastic Disease

Gestational trophoblastic disease encompasses a spectrum of premalignant and malignant conditions. While centralized care models significantly improve survival rates, many countries still lack such specialized centers, leading to preventable deaths. Current research focuses on refining diagnostic and treatment methods, aiming to better predict the risk of malignancy and reduce the need for aggressive therapies. Immunotherapy has emerged as a promising treatment modality, offering high cure rates with fewer side effects compared to traditional chemotherapy. Global efforts must continue to expand access to specialized care and integrate new therapies to improve outcomes and reduce treatment-related harm.

Placental Site Trophoblastic Tumors and Epithelioid Trophoblastic Tumors

Placental site trophoblastic disease (PSTT) and epithelioid trophoblastic tumor (ETT) are the rarest forms of gestational trophoblastic neoplasia (GTN) with unique clinical features and treatment considerations. Unlike other GTN, human chorionic gonadotropin (hCG) is minimally, if at all, elevated. Additionally, unlike other GTN, WHO risk scores are not applied to PSTT/ETT. Management of PSTT/ETT is predominately surgical with hysterectomy and possible lymphadenectomy. There are case reports of fertility sparing surgery for uterine confined disease. Multi-agent chemotherapy ± pembrolizumab is added for those with high risk features defined as advanced stage disease and those diagnosed ≥48 months from the antecedent pregnancy. Survival for early stage, low risk disease remains quite good but the prognosis for high-risk disease is poor and an scenario for which novel treatments are needed.

Pathology of Gestational Trophoblastic Disease (GTD)

Gestational trophoblastic disease (GTD), comprising hydatidiform moles (HM) and gestational trophoblastic tumors (GTT), is extremely rare. HM originate from villous trophoblast and are considered preneoplastic. GTT originate from the intermediate, largely extravillous trophoblast and includes choriocarcinoma, placental site trophoblastic tumor, epitheloid trophoblastic tumor, and mixed trophoblastic tumor. The abnormal (non-molar) villous lesions, non-malignant tumour-like conditions, and non-gestational tumors add to the diagnostic dilemma. The correct diagnosis and classification of these rare conditions are important. This review intends to provide an update on changes in the World Health Organization classification and focusses on the morphologic aspects in diagnosis of GTD.

Atypical placental site nodules: Clinicopathologic features, management and patient outcomes in an institutional series

OBJECTIVE

To report the New England Trophoblastic Disease Center (NETDC) experience with atypical placental site nodules (APSN).

METHODS

The NETDC registry was reviewed from 2005 to 2022 and clinical data abstracted. Expert pathologists in GTD reviewed available slides with concurrent immunohistochemical analysis. Targeted deep sequencing was performed for four cases.

RESULTS

Among 35 cases of APSN identified, 29 had clinical and demographic data available. Abnormal uterine bleeding (59.3%) was the most common presenting symptom. Most women (79.3%) had an antecedent live birth. Two cases were incidentally diagnosed after hysterectomy for other indications, and one case lost to follow-up. Among the remaining 26 cases, 11 (42.3%) opted for hysterectomy and 15 for re-sampling (57.7%), among whom 3 later underwent hysterectomy for persistent APSN. Subsequent obstetrical outcomes included 3 spontaneous abortions, 1 therapeutic abortion, 1 ectopic pregnancy, 2 cesarean sections, 1 cesarean hysterectomy, and 1 spontaneous vaginal delivery. Subsequent pathology was available for 26 cases: 4 epithelioid trophoblastic tumors (15.4%), 9 APSN (34.6%), 3 PSN (11.5%), and 10 without abnormalities (38.4%). Histopathologic characteristics of APSN included moderate to severe cytologic atypia, median Ki-67 proliferation index of 8%, and typical immunohistochemical profiles (diffuse or multifocal positivity for p63 and GATA-3 and absent or focal CD146). No histopathologic feature predicted ETT. Among 4 sequenced cases, no recurrent genomic features were identified.

CONCLUSIONS

APSN is a rare form of gestational trophoblastic proliferation with uncertain malignant potential. While normal obstetric outcomes are possible, the persistence rate is high, and definitive management remains hysterectomy.

Placental site nodules and reproductive outcomes: a clinicopathologic case series

BACKGROUND

Placental site nodules (PSNs) are benign tumor-like growths that develop from chorionic-type intermediate trophoblastic cells. Their clinical significance is unknown. This study aims to determine the risk factors associated with PSNs, with focus on possible reproductive impact.

METHODS

We performed a retrospective case series of all patients with a pathology diagnosis of PSN in a large urban hospital system from 2018 to 2022. We collected clinical variables such as pathology diagnosis/description, presenting symptoms, method of prior delivery, and prior history of infertility, pregnancy loss, and uterine instrumentation.

RESULTS

A total of 32 patients were included in this case series. The most common presenting symptom was abnormal uterine bleeding (40.6%, 13/32). Recurrent pregnancy loss (RPL) (15.6%, 5/32) and infertility (15.6%, 5/32) were common presenting symptoms as well. 62.5% (20/32) patients had a history of prior uterine instrumentation. Coexisting chronic endometritis was identified in 9.4% (3/32) of cases. Of the 5 RPL/infertility patients who underwent hysteroscopic resection of a PSN, 1 achieved a live birth.

CONCLUSION

PSNs may be associated with abnormal uterine bleeding, recurrent pregnancy loss, infertility, history of prior uterine instrumentation, and chronic endometritis. Although a rare diagnosis, the presence of a PSN should be considered in patients presenting for infertility or recurrent pregnancy loss workup.

Appraisal of hydatidiform mole incidence and registration rates in Ireland following the establishment of a National Gestational Trophoblastic Disease Registry

AIMS

This study aimed to re-evaluate the incidence of hydatidiform mole (HM) and determine gestational trophoblastic disease (GTD) registration rates in Ireland following the establishment of the National GTD Registry in 2017.

METHODS

We performed a 3-year retrospective audit of HM cases (January 2017 to December 2019) reported in our centre. In 2019, we surveyed Irish pathology laboratories to determine the number of HMs diagnosed nationally and compared this data to that recorded in the National GTD Registry. Additionally, we compared both local and national HM incidence rates to those reported internationally.

RESULTS

In the 3-year local audit, we identified 87 HMs among 1856 products of conception (POCs) providing a local HM incidence rate of 3.92 per 1000 births. The 1-year pathology survey recorded 170 HMs in 6008 POCs, yielding a national incidence rate of 2.86 per 1000 births. Importantly, the local HM incidence rate exceeded the national incidence rate by 37% and the local partial HM incidence (1 in 296 births) was 64% higher than the nationally incidence rate (1 in 484 births). Notably, 42% of the HM and atypical POCs diagnosed nationally were not reported to the National GTD Registry.

CONCLUSIONS

Our study reveals increased HM incidence rates both locally and nationally compared with previous Irish studies. The higher local PHM incidence may reflect more limited access to ploidy analysis in other pathology laboratories nationally. Significantly, almost half of the women with diagnosed or suspected HM were not registered with the National GTD Centre.

The Rare of the Rarest: Placental Site Trophoblastic Tumor, Epithelioid Trophoblastic Tumor, Atypical Placental Site Nodule

BACKGROUND

Epithelioid Trophoblastic Tumor (ETT) and Placental Site Trophoblastic Tumor (PSTT) are two of the rarest GTNs that share certain features at diagnosis and management. Atypical Placental Site Nodule (APSN) is a relatively new entity considered as a premalignant lesion.

OBJECTIVES AND METHODS

The aim of this review was to summarize the main characteristics of each of these entities, their diagnostic features, and their treatment's standard of care including fertility-sparing treatments.

OUTCOME

This study provides a thorough review of ETT, PSTT, and APSN.

CONCLUSIONS

The reader will gain an insight view of these rare tumors arising from the intermediate trophoblast.

Reconsideration of the Diagnostic Criteria for an Atypical Placental Site Nodule Comparing Typical Placental Site Nodule of the Uterus: A Report of Two Cases

Placental site nodules (PSNs) are non-neoplastic remnants of chorionic-type intermediate trophoblastic cells from a previous gestation that form a well-defined single nodule or multiple nodules in the uterine and extrauterine sites. As the cases of PSNs transformed into gestational trophoblastic tumors were described in the literature, "atypical placental site nodules" (APSNs) have been considered as putative transitional lesions between PSNs and gestational trophoblastic tumors. Although histologic criteria and cutoff point of Ki-67 proliferation index for differentiating an APSN from a typical PSN have not been clearly defined, nodules larger than 5 mm with increased cellularity, a corded or nested appearance, marked nuclear atypia, increased mitotic activity, and an increased Ki-67 proliferation index (>5% or >8%) of intermediate trophoblastic cells seem to be accepted as diagnostic criteria for APSNs. However, some of the criteria, including lesion size and histologic features of the trophoblastic cells in the nodule are not only subjective but have features inherent of the intermediate trophoblastic cells of the fetal membrane and a typical PSN. We thought that it is not reasonable to consider them as diagnostic features of APSNs, if not associated with cellular proliferation. We present 2 cases of incidentally identified PSNs that were larger than 10 mm in size with a corded or nested arrangement of trophoblastic cells, which could have been categorized as APSNs according to the currently proposed criteria to discuss whether the currently proposed diagnostic criteria for APSNs are appropriate.

Surgical Management of Gestational Trophoblastic Disease

BACKGROUND

Gestational trophoblastic disease (GTD) is a rare pregnancy-related condition consisting of premalignant and malignant forms arising from proliferation of trophoblastic cells. The malignant forms are collectively referred to as gestational trophoblastic neoplasia (GTN) and are highly sensitive to chemotherapy. However, surgical procedures remain indispensable in the diagnosis and treatment of GTD.

OBJECTIVES

The aim of this review was to summarize surgical interventions in the treatment of GTD and GTN. We reviewed indications, efficacy, possible complications, and oncological outcomes of surgery.

METHODS

Three searches were performed in the databases of PubMed, Embase, and the Cochrane Library to create an up-to-date overview of existing literature on the following subjects: (1) the role of primary hysterectomy in GTD and GTN; (2) the role of second curettage in GTD and GTN; (3) fertility sparing surgery in GTN; (4) surgical management of metastases. Included articles originated from the time period 1952-2022. Articles written in English, Spanish, and French were included.

OUTCOMES

Thirty-eight articles were found and selected. Surgical evacuation through suction curettage is most used and advised in the treatment of GTD. A second curettage could be beneficial in patients with low hCG levels and low FIGO scores. In women who have completed their families, primary hysterectomy might be considered as the risk of subsequent GTN is lower than after suction curettage. In case of the rare forms of GTN (epithelioid trophoblastic tumor or placental site trophoblastic tumor) surgical tumor resection remains the most important step in treatment. Data on fertility sparing surgery in GTN are scarce and this treatment should be considered experimental.

CONCLUSION AND OUTLOOK

Surgery remains an important part of treatment of GTD and is sometimes indispensable to achieve curation. Further collection of evidence is needed to determine treatment steps.

Recent Advances in the Classification of Gynecological Tract Tumors: Updates From the 5th Edition of the World Health Organization "Blue Book"

CONTEXT.—

The World Health Organization Classification of Tumours: Female Genital Tract Tumors, 5th edition, published in September 2020, comes 6 years after the 4th edition, and reflects the monumental leaps made in knowledge about the biology of gynecological tumors. Major changes include revised criteria for the assignment of the site of origin of ovarian and fallopian tube tumors, a revision in the classification of squamous and glandular lesions of the lower genital tract based on human papillomavirus association, and an entire chapter devoted to genetic tumor syndromes. This article highlights the changes in the 5th edition relative to the 4th edition, with a focus on areas of value to routine clinical practice.

OBJECTIVE.—

To provide a comprehensive update on the World Health Organization classification of gynecological tumors, highlighting in particular updated diagnostic criteria and terminology.

DATA SOURCES.—

The 4th and 5th editions of the World Health Organization Classification of Tumours.

CONCLUSIONS.—

The World Health Organization has made several changes in the 5th edition of the update on female genital tumors. Awareness of the changes is needed for pathologists' translation into contemporary practice.

Application of Current Pathologic Criteria for Atypical Placental Site Nodule Suggests That Refined Criteria Are Needed

Atypical placental site nodules (APSNs) are histologically intermediate between placental site nodules (PSNs) and epithelioid trophoblastic tumors (ETTs). Little data exists to characterize these lesions and the risk of transformation from PSN to ETT. Recent World Health Organization (WHO) criteria for distinction of APSN are vague and not objectively defined. We identified cases signed out as PSN (n=33) and APSN (n=11) and aimed to characterize, statistically compare, and assess the risk of transformation in PSNs using data including size, location, mitotic rate, Ki-67 proliferation index, trophoblastic cells per high-power field, presence of severe cytologic atypia, beta-human chorionic gonadotropin levels, time since last pregnancy, presence of calcification, necrosis, or apoptosis, and follow-up results. All cases were confirmed to be positive for p63, and a Ki-67/AE1/AE3 dual stain was used to evaluate the Ki-67 proliferation index in the trophoblastic cells. In our cohort, slight changes in the interpretation of WHO criteria for PSN and APSN led to marked differences in the proportion of PSNs flagged as "atypical." There was no statistically significant difference in the persistence of APSN versus non-APSN. None of the PSNs transformed to ETT. Current criteria for distinction between PSN and APSN are largely subjective. More objective, clearly defined, and clinically meaningful criteria are needed to distinguish between PSN and APSN, thus aiding in assessing the rare risk of transformation to ETT.

Gestational trophoblastic disease: an update

Gestational trophoblastic diseases (GTD) encompass a spectrum of rare pre-malignant and malignant entities originating from trophoblastic tissue. This updated review will highlight important radiological features, pathology and classification, and provide insight into the clinical management of these uncommon disorders. There is a wide geographic variation with the incidence of hydatidiform mole varying between 0.57 and 2 per 1000 pregnancies. The use of ultrasound (US) in the management of early pregnancy symptoms and complications has positively impacted the earlier detection of these diseases and resulted in diminished morbidity. Additional imaging modalities are reserved for problem solving or assessment of pulmonary manifestations of molar pregnancy. Having an awareness of their pleomorphic sonographic presentation and additional pathology that can mimic GTD is critical to avoiding pitfalls. Histologic and molecular analysis further aids in differential diagnosis. Gestational trophoblastic neoplasia (GTN) is inclusive of all malignant GTDs, and arises after 20% of molar pregnancies but can also be seen with non-molar gestations. Biochemical monitoring with human chorionic gonadotrophin is imperative for ongoing monitoring and surveillance and allows early detection of this entity. Doppler US is used for confirmation of diagnosis with magnetic resonance imaging (MRI) reserved for problem solving or assessment of myometrial invasion. This is of heightened relevance in patients undergoing surgical management. Cross sectional imaging is reserved for patients in the setting of GTN for the purposes of staging, prognostication and in the setting of recurrent disease. This may require a combination of computed tomography, MRI and positron emission tomography. Doppler US can provide insight into chemotherapeutic response/predict resistance in patients with GTN. As our understanding of these disorders evolves, there has been maturation in management options with a shift from traditional chemotherapy to innovative immunotherapy, particularly in the setting of resistant or high-risk disease.

Molecular Analyses of Chorionic-Type Intermediate Trophoblastic Lesions: Atypical Placental Site Nodules are Closer to Placental Site Nodules Than Epithelioid Trophoblastic Tumors

Gestational trophoblastic diseases derived from the chorionic-type intermediate trophoblast include benign placental site nodule (PSN) and malignant epithelioid trophoblastic tumor (ETT). Among PSNs, the World Health Organization classification introduced a new entity named atypical placental site nodule (APSN), corresponding to an ETT precursor, for which diagnostic criteria remain unclear, leading to a risk of overdiagnosis and difficulties in patient management. We retrospectively studied 8 PSNs, 7 APSNs, and 8 ETTs to better characterize this new entity and performed immunohistochemical analysis (p63, human placental lactogen, Cyclin E, and Ki67), transcriptional analysis using the NanoString method to quantify the expression of 760 genes involved in the main tumorigenesis pathways, and RNA sequencing to identify fusion transcripts. The immunohistochemical analysis did not reveal any significant difference in Cyclin E expression among the 3 groups (P = .476), whereas the Ki67 index was significantly (P < .001) higher in ETT samples than in APSN and PSN samples. None of the APSN samples harbored the LPCAT1::TERT fusion transcripts, in contrast to 1 of 6 ETT samples, as previously described in 2 of 3 ETT samples. The transcriptomic analysis allowed robust clustering of ETTs distinct from the APSN/PSN group but failed to differentiate APSNs from PSNs. Indeed, only 7 genes were differentially expressed between PSN and APSN samples; CCL19 upregulation and EPCAM downregulation were the most distinguishing features of APSNs. In contrast, 80 genes differentiated ETTs from APSNs, establishing a molecular signature for ETT. Gene set analysis identified significant enrichments in the DNA damage repair, immortality and stemness, and cell cycle signaling pathways when comparing ETTs and APSNs. These results suggested that APSN might not represent a distinct entity but rather a transitional stage between PSN and ETT. RNA sequencing and the transcriptional signature of ETT described herein could serve as triage for APSN from curettage or biopsy material, enabling the identification of cases that need further clinical investigations.

Case Report: Tubal Atypical Placental Site Nodule

Placental site nodule (PSN) is a benign proliferation of chorionic-type intermediate trophoblastic cells that forms a tumor-like lesion. Most PSNs are intrauterine, but a few have been reported outside the uterus, including in fallopian tubes. PSN is related to epithelioid trophoblastic tumor (ETT) in that both are composed of chorionic-type intermediate trophoblastic cells, while ETT is hypercellular and contains trophoblastic cells with increased nuclear atypia and a higher Ki-67 proliferation index as compared with PSN. Occasionally, an intermediate stage between a PSN and an ETT is observed, and such a lesion is often recognized as an atypical PSN (aPSN) characterized by trophoblastic cells exhibiting morphologic features in transition from a conventional PSN to an ETT. aPSN has been thought to exhibit benign behavior; however, it has also been reported that up to 15% of aPSN lesions either coexist with, or subsequently develop into, ETT. To the best of our knowledge, there has been no case report of an aPSN in an extrauterine site. Here, we reported a highly unusual case of tubal aPSN, which illustrates several key features associated with PSN and its possible pathogenesis.

Epithelioid Trophoblastic Tumor Presenting as an Adnexal Mass: Report of a Diagnostically Challenging Case

Epithelioid trophoblastic tumor (ETT) is a rare neoplasm derived from chorionic intermediate trophoblast cells, representing less than 2% of all gestational trophoblastic neoplasms. Classically, ETT presents as a uterine mass in women of reproductive age following a term pregnancy. The time from pregnancy to tumor development varies from months to several years. ETT most often arises in the endometrium, followed by the cervix. Extrauterine ETT are extremely infrequent, with few cases reported in the literature. We report a case of a 41-year-old woman, with history of three term pregnancies who presented with abdominal pain and elevated beta human chorionic gonadotropin (β-hCG) level, ten years after her last pregnancy. Imaging reported a 3.5 cm adnexal mass, suspicious for ectopic pregnancy. Hysterectomy and mass resection revealed a 4.7 cm, tan-yellow, necrotic mass adjacent to the broad ligament. Histologic evaluation in conjunction with immunohistochemical stains revealed a tumor consistent with ETT. No connection to the endometrium was found grossly or microscopically. DNA fingerprinting analysis revealed the tumor to have two copies of paternal alleles, as seen in molar gestations. One of the primary differential diagnoses for ETT is squamous cell carcinoma due to similar morphologic features. In challenging cases, genetic analysis demonstrating paternally derived genes can establish the diagnosis. In this report, we discuss the challenges in the diagnosis of extrauterine ETT, due to its rarity and highly variable presentation, given that appropriate diagnosis is critical for correct patient management.

Gestational Trophoblastic Disease: Contemporary Diagnostic Approach

Pathologic diagnosis of gestational trophoblastic disease (GTD)-hydatidiform moles and gestational trophoblastic neoplasms-underwent a major shift in the past decade from morphology-based recognition to precise molecular genetic classification of entities, which also allows for prognostic stratification of molar gestations. This article highlights these recent advances and their integration into the routine pathology practice. The traditional gross and histomorphologic features of each entity are also reviewed with special focus on differential diagnoses and their clinical implications.

Bizarre Chorionic-type Trophoblast in Second-trimester and Third-trimester Placentas: Clinicopathologic Characterization of a Placental Pseudoneoplastic Lesion

Bizarre (atypical/symplastic) cells have been described in various gynecologic normal tissues and benign neoplasms. This type of bizarre cytologic change is usually an incidental finding and is regarded as a benign process. We describe 17 cases of bizarre chorionic-type trophoblast in second-trimester and third-trimester placentas that created concern for an underlying/undersampled or incipient intraplacental trophoblastic neoplasm, predominantly found in intervillous trophoblastic islands (11/17), placental septae (6/17), chorionic plate (1/17), and/or the chorion layer of fetal membranes (2/17). The bizarre trophoblastic cells exhibited sheet-like or nested architecture, had a multifocal/patchy distribution, and/or were present as individual cells within hyaline stroma; they were characterized by large nuclei with smudgy chromatin and occasional intranuclear pseudoinclusions. The degree of atypia was classified as mild (0/17), moderate (3/17), or severe (14/17). Mitotic figures and necrosis were not identified. A dual immunohistochemical stain for trophoblast (hydroxyl-delta-5-steroid dehydrogenase) and a proliferation marker (Ki-67), performed in 15 cases, demonstrated 0% to very low proliferative activity within the bizarre trophoblast (0% to 2% [10/15], 3% to 8% [5/15]). Immunohistochemical stains for fumarate hydratase showed intact/retained expression in the bizarre cells in 7 of 7 cases. Clinical follow-up ranged from 1 to 45 months, and all patients were alive and well without subsequent evidence of a gestational trophoblastic or other neoplasms. We conclude that bizarre chorionic-type trophoblast in second-trimester or third-trimester placentas have the potential to mimic an intraplacental trophoblastic neoplasm but are likely a benign degenerative change. This study expands the spectrum of bizarre cells that occur in the gynecologic tract.

Key changes to the world health organisation (who) classification of female genital tumours introduced in the 5TH edition (2020)

An updated World Health Organisation (WHO) Classification of Female Genital Tumours was published in Autumn 2020. We discuss the major new additions and changes from the prior 2014 Classification with discussion of the reasons underlying these. A feature of the new Classification is the greater emphasis on key molecular events with integration of morphological and-molecular features. Most of the major changes from the prior Classification pertain to uterine (corpus and cervix) and vulval tumours but changes in all organs are covered.

Advances in the diagnosis and early management of gestational trophoblastic disease

Gestational trophoblastic disease describes a group of rare pregnancy related disorders that span a spectrum of premalignant and malignant conditions. Hydatidiform mole (also termed molar pregnancy) is the most common form of this disease. Hydatidiform mole describes an abnormal conceptus containing two copies of the paternal genome, which is classified as partial when the maternal genome is present or complete when the maternal genome is absent. Hydatidiform mole typically presents in the first trimester with irregular vaginal bleeding and can be suspected on ultrasound but confirmation requires histopathological evaluation of the products of conception. Most molar pregnancies resolve without treatment after uterine evacuation, but occasionally the disease persists and develops into gestational trophoblastic neoplasia. Close monitoring of women after molar pregnancy, with regular measurement of human chorionic gonadotrophin concentrations, allows for early detection of malignancy. Given the rarity of the disease, clinical management and treatment is best provided in specialist centres where very high cure rates are achievable. This review looks at advances in the diagnosis and early management of gestational trophoblastic disease and highlights updates to disease classification and clinical guidelines. Use of molecular genotyping for improved diagnostic accuracy and risk stratification is reviewed and future biomarkers for the earlier detection of malignancy are considered.

OUP accepted manuscript

BACKGROUND

Gestational trophoblastic diseases (GTDs) may follow any form of pregnancy or a pregnancy loss. Early detection of GTDs is important, as some benign forms of the disease may progress into a chemoresistant and metastatic disease. This study aimed at determining the frequency of GTDs among women experiencing first trimester pregnancy loss and the associated patients' characteristics.

METHODS

This was a cross-sectional study that included 200 conveniently sampled women who experienced first trimester pregnancy loss from January to December 2019 at a Regional Referral Hospital in central Tanzania. The specimen obtained from products of conception were collected, formalin-fixed and paraffin-embedded and submitted for histopathological evaluation, for which haematoxylin and eosin stain was used. Data were analysed using SPSS version 23.0. The χ2 test was used to determine the association between categorical variables. p-Values ˂0.05 were considered statistically significant.

RESULTS

Among 200 study participants, the overall frequency of GTDs was 42 (21%). Among those with GTDs, the most common histopathological diagnosis was partial hydatidiform mole (18 [42.9%]), followed by complete hydatidiform mole (17 [40.5%]) and choriocarcinoma (7 [16.5%]). In the studied participants, only increased human chorionic gonadotropin hormone levels were found to be statistically significantly associated with GTDs (p=0.000).

CONCLUSIONS

Results from this study suggest that routine histopathological evaluation of the products of conception is recommended in order to allow early detection of GTDs, including choriocarcinoma, which usually carries a poor prognosis. The histopathological reporting of choriocarcinoma among first trimester products of conception from Tanzania is novel.

Diagnosis and management of gestational trophoblastic disease: 2021 update

Gestational trophoblastic disease (GTD) arises from abnormal placenta and is composed of a spectrum of premalignant to malignant disorders. Changes in epidemiology of GTD have been noted in various countries. In addition to histology, molecular genetic studies can help in the diagnostic pathway. Earlier detection of molar pregnancy by ultrasound has resulted in changes in clinical presentation and decreased morbidity from uterine evacuation. Follow-up with human chorionic gonadotropin (hCG) is essential for early diagnosis of gestational trophoblastic neoplasia (GTN). The duration of hCG monitoring varies depending on histological type and regression rate. Low-risk GTN (FIGO Stages I-III: score <7) is treated with single-agent chemotherapy but may require additional agents; although scores 5-6 are associated with more drug resistance, overall survival approaches 100%. High-risk GTN (FIGO Stages II-III: score ≥7 and Stage IV) is treated with multiagent chemotherapy, with or without adjuvant surgery for excision of resistant foci of disease or radiotherapy for brain metastases, achieving a survival rate of approximately 90%. Gentle induction chemotherapy helps reduce early deaths in patients with extensive tumor burden, but late mortality still occurs from recurrent treatment-resistant tumors.

Guideline No. 408: Management of Gestational Trophoblastic Diseases

OBJECTIVE

This guideline reviews the clinical evaluation and management of gestational trophoblastic diseases, including surgical and medical management of benign, premalignant, and malignant entities. The objective of this guideline is to assist health care providers in promptly diagnosing gestational trophoblastic diseases, to standardize treatment and follow-up, and to ensure early specialized care of patients with malignant or metastatic disease.

INTENDED USERS

General gynaecologists, obstetricians, family physicians, midwives, emergency department physicians, anaesthesiologists, radiologists, pathologists, registered nurses, nurse practitioners, residents, gynaecologic oncologists, medical oncologists, radiation oncologists, surgeons, general practitioners in oncology, oncology nurses, pharmacists, physician assistants, and other health care providers who treat patients with gestational trophoblastic diseases. This guideline is also intended to provide information for interested parties who provide follow-up care for these patients following treatment.

TARGET POPULATION

Women of reproductive age with gestational trophoblastic diseases.

OPTIONS

Women diagnosed with a gestational trophoblastic disease should be referred to a gynaecologist for initial evaluation and consideration for primary surgery (uterine evacuation or hysterectomy) and follow-up. Women diagnosed with gestational trophoblastic neoplasia should be referred to a gynaecologic oncologist for staging, risk scoring, and consideration for primary surgery or systemic therapy (single- or multi-agent chemotherapy) with the potential need for additional therapies. All cases of gestational trophoblastic neoplasia should be discussed at a multidisciplinary cancer case conference and registered in a centralized (regional and/or national) database.

EVIDENCE

Relevant studies from 2002 onwards were searched in Embase, MEDLINE, the Cochrane Central Register of Controlled Trials, and Cochrane Systematic Reviews using the following terms, either alone or in combination: trophoblastic neoplasms, choriocarcinoma, trophoblastic tumor, placental site, gestational trophoblastic disease, hydatidiform mole, drug therapy, surgical therapy, radiotherapy, cure, complications, recurrence, survival, prognosis, pregnancy outcome, disease outcome, treatment outcome, and remission. The initial search was performed in April 2017 and updated in May 2019. Relevant evidence was selected for inclusion in the following order: meta-analyses, systematic reviews, guidelines, randomized controlled trials, prospective cohort studies, observational studies, non-systematic reviews, case series, and reports. Additional significant articles were identified through cross-referencing the identified reviews. The total number of studies identified was 673, with 79 studies cited in this review.

VALIDATION METHODS

The content and recommendations were drafted and agreed upon by the authors. The Executive and Board of Directors of the Society of Gynecologic Oncology of Canada reviewed the content and submitted comments for consideration, and the Board of Directors for the Society of Obstetricians and Gynaecologists of Canada approved the final draft for publication. The quality of evidence was rated using the criteria described in the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology framework. See the online appendix tables for key to grading and interpretation of recommendations.

BENEFITS

These guidelines will assist physicians in promptly diagnosing gestational trophoblastic diseases and urgently referring patients diagnosed with gestational trophoblastic neoplasia to gynaecologic oncology for specialized management. Treating gestational trophoblastic neoplasia in specialized centres with the use of centralized databases allows for capturing and comparing data on treatment outcomes of patients with these rare tumours and for optimizing patient care.

SUMMARY STATEMENTS (GRADE RATINGS IN PARENTHESES)

RECOMMENDATIONS (GRADE RATINGS IN PARENTHESES).

Progress to international harmonisation of care and future developments

Considerable differences exist in the management of gestational trophoblastic disease (GTD) both nationally and internationally despite numerous efforts to harmonise patient care. This partly reflects differences in healthcare systems and availability of resources. However, even in first world equivalent economies with similar healthcare systems differences remain, which appear to impact survival. Recently, new international guidelines have been established in Europe through a series of consensus meetings. Improvement of outcomes will depend on the establishment of dedicated centres with appropriate patient pathways according to these guidelines. This review will highlight some of the differences and efforts to unify the management of GTD across the globe and discuss areas for future development.

Pathology of gestational trophoblastic disease (GTD)

Gestational trophoblastic disease (GTD) is subclassified into hydatidiform mole (HM), gestational trophoblastic tumours (GTT) and non-neoplastic trophoblastic lesions. HM, partial and complete, originate from villous trophoblast and are considered as preneoplastic conditions. The risk for the development of persistent GTD, mostly as invasive HM, ranges from 0.5% to 20%, which depends on the type of molar pregnancy. The risk of development of trophoblastic tumour after PHM is <0.5% and 2%-3% after CHM. GTT represent a spectrum of neoplasms that originates from the intermediate, largely extravillous, trophoblast and these include choriocarcinoma (CC), placental site trophoblastic tumour (PSTT), epithelioid trophoblastic tumour (ETT) and mixed trophoblastic tumour. Among tumour like conditions, exaggerated placental site reaction (EPSR) and placental site nodule (PSN) (s)/plaque (s) are included. The morphological appearances of HM can be mimicked by abnormal (non-molar) villous lesions, and similarly, GTT can be mimicked both by non-malignant tumour-like conditions and non-gestational tumours with trophoblastic differentiation, which add to the diagnostic dilemma of these rare conditions. GTT have a favourable prognosis and better response to specific chemotherapeutic regimens when compared with non-gestational malignant genital tract neoplasms. The correct diagnosis and classification of these rare conditions are therefore important. This article focusses on the morphological appearances, immunocytochemistry as an aid in the diagnosis and the changes in current WHO classification of GTDs (WHO 2020).

Fertility and pregnancy outcome in gestational trophoblastic disease

The aim of this review is to provide an overview of existing literature and current knowledge on fertility rates and reproductive outcomes after gestational trophoblastic disease. A systematic literature search was performed to retrieve all available studies on fertility rates and reproductive outcomes after hydatidiform mole pregnancy, low-risk gestational trophoblastic neoplasia, high- and ultra-high-risk gestational trophoblastic neoplasia, and the rare placental site trophoblastic tumor and epithelioid trophoblastic tumor forms of gestational trophoblastic neoplasia. The effects of single-agent chemotherapy, multi-agent including high-dose chemotherapy, and immunotherapy on fertility, pregnancy wish, and pregnancy outcomes were evaluated and summarized. After treatment for gestational trophoblastic neoplasia, most, but not all, women want to achieve another pregnancy. Age and extent of therapy determine if there is a risk of loss of fertility. Single-agent treatment does not affect fertility and subsequent pregnancy outcome. Miscarriage occurs more often in women who conceive within 6 months of follow-up after chemotherapy. Multi-agent chemotherapy hastens the natural menopause by three years and commonly induces a temporary amenorrhea, but in young women rarely causes permanent ovarian failure or infertility. Subsequent pregnancies have a high chance of ending with live healthy babies. In contrast, high-dose chemotherapy typically induces permanent amenorrhea, and no pregnancies have been reported after high-dose chemotherapy for gestational trophoblastic neoplasia. Immunotherapy is promising and may give better outcomes than multiple schedules of chemotherapy or even high-dose chemotherapy. The first pregnancy after immunotherapy has recently been described. Data on fertility-sparing treatment in placental site trophoblastic tumor and epithelioid trophoblastic tumor are still scarce, and this option should be offered with caution. In general, patients with gestational trophoblastic neoplasia may be reassured about their future fertility and pregnancy outcome. Detailed registration of high-risk gestational trophoblastic neoplasia is still indispensable to obtain more complete data to better inform patients in the future.

Genetics of gestational trophoblastic disease

The abnormal pregnancies complete and partial hydatidiform mole are genetically unusual, being associated with two copies of the paternal genome. Typical complete hydatidiform moles (CHMs) are diploid and androgenetic, while partial hydatidiform moles (PHMs) are diandric triploids. While diagnosis can usually be made on the basis of morphology, ancillary techniques that exploit their unusual genetic origin can be used to facilitate diagnosis. Genotyping and p57 immunostaining are now routinely used in the differential diagnosis of complete and partial hydatidiform moles, for investigating unusual mosaic or chimeric products of conception with a molar component and identifying the rare diploid, biparental HMs associated with an inherited predisposition to molar pregnancies. Genotyping also plays an important role in the differential diagnosis of gestational and non-gestational trophoblastic tumours and identification of the causative pregnancy where tumours are gestational. Recent developments include the use of cell-free DNA for non-invasive diagnosis of these conditions.

Treatment of gestational trophoblastic disease in the 2020s

PURPOSE OF REVIEW

This review demonstrates the evidence for new systemic anticancer treatments and how they integrate within conventional management for gestational trophoblastic neoplasia (GTN). We present the evidence on atypical placental site nodules, and how they incorporate within the GTN spectrum, as well as updates regarding GTN staging and follow-up.

RECENT FINDINGS

First-line treatment for GTN still lies in conventional chemotherapy, although the introduction of anti-PD1/PD-L1 immune checkpoint inhibitors has shown significant promise in management of relapsed disease, with responses reported in multiple relapsed choriocarcinomas as well as epithelioid trophoblastic tumours and placental site trophoblastic tumours (ETT/PSTT). Following completion of treatment, ETT/PSTT still require life-long surveillance but for other GTN, no recurrences have been detected after 7 years.

SUMMARY

Checkpoint inhibitors are likely to play an increasing role in the future management of GTN management. Further refinement of prognostic factors to identify those most at risk of GTN recurrence is warranted so that surveillance can be focussed on those most at risk, whilst minimizing unnecessary intervention for those at lower risk.

A Rare Case of Atypical Placental Site Nodule With an Emerging Intermediate Trophoblastic Tumor

Placental site nodule (PSN) is a benign lesion composed of chorionic-type intermediate trophoblastic cells and is typically an incidental finding in uterine or endocervical curettage specimens. Epithelioid trophoblastic tumor (ETT) and placental site trophoblastic tumor (PSTT) are intermediate trophoblastic neoplasms of chorionic and implantation site types, respectively. ETT is speculated to be the neoplastic counterpart of PSN. The term atypical placental site nodule (APSN) has been proposed for PSN-type lesions displaying one or more concerning features, including larger size/more abundant lesional tissue, more extensive plaque-like growth, increased cellularity with more cohesive nests and cords of cells, a greater extent/distribution of necrosis, increased atypia, mitotic activity, and/or a Ki-67 proliferation index greater than usually encountered in the typical PSN. It has been proposed that APSN is an intermediary lesion between PSN and intermediate trophoblastic tumors, more commonly ETT but also PSTT. We report a case of a 39-yr-old woman who developed abnormal uterine bleeding 44 mo after her last recognized pregnancy. An endometrial curettage specimen demonstrated an APSN with some features concerning for an intermediate trophoblastic tumor. A hysterectomy specimen demonstrated residual APSN with foci consistent with emerging PSTT and ETT. This case illustrates the earliest form of PSTT and ETT arising in association with an APSN and supports interpretation of APSN as an intermediary lesion between typical PSN and intermediate trophoblastic tumors.

Directive clinique no 408 : Prise en charge des maladies gestationnelles trophoblastiques

OBJECTIF

Cette directive passe en revue l'évaluation clinique et la prise en charge des maladies gestationnelles trophoblastiques, notamment les traitements chirurgicaux et médicamenteux des tumeurs bénignes, prémalignes et malignes. L'objectif de la présente directive clinique est d'aider les fournisseurs de soins de santé à rapidement diagnostiquer les maladies gestationnelles trophoblastiques, à normaliser les traitements et le suivi et à assurer des soins spécialisés précoces aux patientes dont l'atteinte est maligne ou métastatique. PROFESSIONNELS CONCERNéS: Gynécologues généralistes, obstétriciens, médecins de famille, sages-femmes, urgentologues, anesthésistes, radiologistes, anatomopathologistes, infirmières autorisées, infirmières praticiennes, résidents, gynécologues-oncologues, oncologues médicaux, radio-oncologues, chirurgiens, omnipraticiens en oncologie, infirmières en oncologie, pharmaciens, auxiliaires médicaux et autres professionnels de la santé qui traitent des patientes atteintes d'une maladie gestationnelle trophoblastique. La présente directive vise également à fournir des renseignements aux parties intéressées qui prodiguent des soins de suivi à ces patientes après le traitement.

POPULATION CIBLE

Femmes en âge de procréer atteintes d'une maladie gestationnelle trophoblastique.

OPTIONS

Les femmes ayant reçu un diagnostic de maladie gestationnelle trophoblastique doivent être orientées vers un gynécologue afin qu'il réalise une évaluation initiale, envisage une intervention chirurgicale primaire (évacuation ou hystérectomie) et effectue un suivi. Il y a lieu d'orienter les femmes ayant reçu un diagnostic de tumeur trophoblastique gestationnelle vers un gynécologue-oncologue afin qu'il effectue la stadification tumorale, établisse le score de risque et envisage l'intervention chirurgicale primaire ou un traitement systémique (mono- ou polychimiothérapie) et la nécessité d'éventuels traitements supplémentaires. Il est recommandé de discuter de chaque cas de néoplasie gestationnelle trophoblastique lors d'une réunion multidisciplinaire de cas oncologiques et de l'inscrire dans une base de données centralisée (régionale et/ou nationale). DONNéES PROBANTES: Des recherches ont été effectuées au moyen des bases de données Embase et MEDLINE, du Cochrane Central Register of Controlled Trials et de la Cochrane Database of Systematic Reviews afin de trouver les études publiées depuis 2002 utilisant un ou plusieurs des mots clés suivants : trophoblastic neoplasms, choriocarcinoma, trophoblastic tumor, placental site, gestational trophoblastic disease, hydatidiform mole, drug therapy, surgical therapy, radiotherapy, cure, complications, recurrence, survival, prognosis, pregnancy outcome, disease outcome, treatment outcome et remission. La recherche initiale a été effectuée en avril 2017; une mise à jour a été faite en mai 2019. Les données probantes pertinentes ont été sélectionnées aux fins d'inclusion selon l'ordre suivant : méta-analyses, revues systématiques, directives cliniques, essais cliniques randomisés, études de cohortes prospectives, études observationnelles, revues non systématiques, études de séries de cas et rapports. D'autres articles pertinents ont été trouvés en recoupant les revues répertoriées. Le nombre total d'études relevées était de 673, dont 79 études sont citées dans la présente revue. MéTHODES DE VALIDATION: Le contenu et les recommandations ont été rédigés et acceptés par les auteurs. La direction et le conseil d'administration de la Société de gynéco-oncologie du Canada ont passé en revue le contenu de la version préliminaire et ont soumis des commentaires à prendre en considération. Le conseil d'administration de la Société des obstétriciens et gynécologues du Canada a approuvé la version définitive aux fins de publication. La qualité des données probantes a été évaluée au moyen des critères de l'approche GRADE (Grading of Recommendations Assessment, Development and Evaluation). Consulter les tableaux dans l'annexe en ligne pour connaître les critères de notation et d'interprétation des recommandations. BéNéFICES, RISQUES, COûTS: Les présentes recommandations aideront les médecins à diagnostiquer rapidement les maladies gestationnelles trophoblastiques et à orienter de façon urgente les patientes ayant reçu un diagnostic de maladie gestationnelle trophoblastique en gynécologie oncologique pour une prise en charge spécialisée. Le traitement des néoplasies gestationnelles trophoblastiques en centre spécialisé combiné à l'utilisation de bases de données centralisées permet de recueillir et de comparer des données sur les résultats thérapeutiques des patientes atteintes de ces tumeurs rares et d'optimiser les soins aux patientes. DÉCLARATIONS SOMMAIRES (CLASSEMENT GRADE ENTRE PARENTHèSES): RECOMMANDATIONS (CLASSEMENT GRADE ENTRE PARENTHèSES).

Placental site trophoblastic tumour and epithelioid trophoblastic tumour

Placental site trophoblastic tumour (PSTT) and epithelioid trophoblastic tumour (ETT) are the rarest subtypes of gestational trophoblastic disease (GTD). Their diagnosis is complicated and lacks specific and sensitive tumour markers. They are slow-growing tumours and can occur months to years after any type of antecedent pregnancy. The primary treatment for localised disease is hysterectomy. However, extra-uterine invasion and/or metastasis occur in about one-third of cases and still cause death in a small number. Most patients are young; hence, fertility preservation is a consideration. The major obstacle for prognosis is chemotherapy resistance. The current understanding of these tumours remains elusive and no randomized controlled trials have been done. Even those centres treating a large number of patients with GTD will infrequently manage PSTT/ETT. In this review, we assess progress in the understanding of the disease and discuss four main clinical challenges - establishing conformity of practice, devising a risk-adapted approach to clinical management, establishing long-term follow-up data and evaluating therapies for poor prognosis and multi drug-resistant patients.

Invasive mole in a perimenopausal woman with lung and vaginal metastases: A case report

Gestational trophoblastic disease can result in serious complications and disease progression. Therefore, follow-up of such patients is essential for early detection of malignant trophoblastic tumors and to reduce mortality rate. Primary treatment is chemotherapy but hysterectomy should be considered in patients who have uncontrollable hemorrhage and hemodynamic instability.

Challenges in the diagnosis and treatment of gestational trophoblastic neoplasia worldwide

Gestational trophoblastic neoplasia (GTN) is a rare tumor that originates from pregnancy that includes invasive mole, choriocarcinoma (CCA), placental site trophoblastic tumor and epithelioid trophoblastic tumor (PSTT/ETT). GTN presents different degrees of proliferation, invasion and dissemination, but, if treated in reference centers, has high cure rates, even in multi-metastatic cases. The diagnosis of GTN following a hydatidiform molar pregnancy is made according to the International Federation of Gynecology and Obstetrics (FIGO) 2000 criteria: four or more plateaued human chorionic gonadotropin (hCG) concentrations over three weeks; rise in hCG for three consecutive weekly measurements over at least a period of 2 weeks or more; and an elevated but falling hCG concentrations six or more months after molar evacuation. However, the latter reason for treatment is no longer used by many centers. In addition, GTN is diagnosed with a pathological diagnosis of CCA or PSTT/ETT. For staging after a molar pregnancy, FIGO recommends pelvic-transvaginal Doppler ultrasound and chest X-ray. In cases of pulmonary metastases with more than 1 cm, the screening should be complemented with chest computed tomography and brain magnetic resonance image. Single agent chemotherapy, usually Methotrexate (MTX) or Actinomycin-D (Act-D), can cure about 70% of patients with FIGO/World Health Organization (WHO) prognosis risk score ≤ 6 (low risk), reserving multiple agent chemotherapy, such as EMA/CO (Etoposide, MTX, Act-D, Cyclophosphamide and Oncovin) for cases with FIGO/WHO prognosis risk score ≥ 7 (high risk) that is often metastatic. Best overall cure rates for low and high risk disease is close to 100% and > 95%, respectively. The management of PSTT/ETT differs and cure rates tend to be a bit lower. The early diagnosis of this disease and the appropriate treatment avoid maternal death, allow the healing and maintenance of the reproductive potential of these women.

Update on the diagnosis and management of gestational trophoblastic disease

Gestational trophoblastic disease (GTD) arises from abnormal placenta and is composed of a spectrum of premalignant to malignant disorders. Changes in epidemiology of GTD have been noted in various countries. In addition to histology, molecular genetic studies can help in the diagnostic pathway. Earlier detection of molar pregnancy by ultrasound has resulted in changes in clinical presentation and decreased morbidity from uterine evacuation. Follow-up with human chorionic gonadotropin (hCG) is essential for early diagnosis of gestational trophoblastic neoplasia (GTN). The duration of hCG monitoring varies depending on histology type and regression rate. Low-risk GTN (FIGO Stages I-III: score <7) is treated with single-agent chemotherapy but may require additional agents; although scores 5-6 are associated with more drug resistance, overall survival approaches 100%. High-risk GTN (FIGO Stages II-III: score >7 and Stage IV) is treated with multiple agent chemotherapy, with or without adjuvant surgery for excision of resistant foci of disease or radiotherapy for brain metastases, achieving a survival rate of approximately 90%. Gentle induction chemotherapy helps reduce early deaths in patients with extensive tumor burden, but late mortality still occurs from recurrent resistant tumors.

Gestational Trophoblastic Tumors: A Timely Review of Diagnostic Pathology

CONTEXT.—

Gestational trophoblastic tumors include 3 distinct entities: gestational choriocarcinoma, placental site trophoblastic tumor, and epithelioid trophoblastic tumor. Accurate diagnosis is important for clinical management of the patient.

OBJECTIVE.—

To review clinical features and pathologic diagnosis of gestational trophoblastic tumors.

DATA SOURCES.—

Literature and personal experience are the sources for this study.

CONCLUSIONS.—

Trophoblastic tumors are rare encounters in modern medicine, as a result of clinical practice of molar surveillance programs and early chemotherapeutic intervention for persistent gestational trophoblastic neoplasia. Diagnostic recognition of these tumors requires a high index of suspicion, awareness of their histologic characteristics, and appropriate application of immunohistochemical and molecular biomarkers. Recent attention has been given to a few precursor lesions of gestational trophoblastic tumors, including early/in situ choriocarcinoma and atypical placental site nodule.

A typical postcesarean epithelioid trophoblastic lesion with placenta increta: Case report and literature review

We report an extremely rare case of unusual atypical epithelioid trophoblastic lesion from placenta increta. A 25-year-old Chinese woman with a history of 1 cesarean delivery was admitted to the hospital at 37 weeks' gestation. Magnetic resonance imaging (MRI) showed the feature of placenta increta. An elective primary cesarean section was scheduled and a healthy baby was born. The patient was suggestive of placenta increta and implantation site was resected. Histology indicated a lesion consisting of epithelioid trophoblastic cells with an intermediate pattern between a classical placental site nodule and an epithelioid trophoblastic tumor. This may be linked to her previous cesarean delivery, which supports the relationship between atypical epithelioid trophoblastic lesion formation and surgical interventions. Her serum human chorionic gonadotropin (hCG) was 352.4 IU/L after delivery and gradually decreased to normal level.

Atypical Placental Site Nodule Arising in a Postcesarean Section Scar: Case Report and Review of the Literature

The distinction between benign and malignant trophoblastic lesions often presents a diagnostic challenge, even in entities with defined morphologic and immunohistochemical criteria. Lesions arising from chorionic-type intermediate trophoblast, namely placental site nodule (PSN) and epithelioid trophoblastic tumor (ETT), can be distinguished by existing criteria. However, a putative intermediate lesion termed "atypical placental site nodule" (APSN) has been described in the literature but is not well-classified. We present a case of APSN, along with a brief literature review, and we propose more definitive morphologic and immunohistochemical criteria for this entity, in order to facilitate easier diagnosis and gather more information regarding outcomes.

Gestational and Non-gestational Trophoblastic Disease. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry No. 032/049, December 2015)

Purpose: The aim was to establish an official interdisciplinary guideline, published and coordinated by the German Society of Gynecology and Obstetrics (DGGG). The guideline was developed for use in German-speaking countries. In addition to the Germany Society of Gynecology and Obstetrics, the guideline has also been approved by the Swiss Society of Gynecology and Obstetrics (SGGG) and the Austrian Society of Gynecology and Obstetrics (OEGGG). The aim was to standardize diagnostic procedures and the management of gestational and non-gestational trophoblastic disease in accordance with the principles of evidence-based medicine, drawing on the current literature and the experience of the colleagues involved in compiling the guideline. Methods: This s2k guideline represents the consensus of a representative panel of experts with a range of different professional backgrounds commissioned by the DGGG. Following a review of the international literature and international guidelines on trophoblastic tumors, a structural consensus was achieved in a formalized, multi-step procedure. This was done using uniform definitions, objective assessments, and standardized management protocols. Recommendations: The recommendations of the guideline cover the epidemiology, classification and staging of trophoblastic tumors; the measurement of human chorionic gonadotropin (hCG) levels in serum, and the diagnosis, management, and follow-up of villous trophoblastic tumors (e.g., partial mole, hydatidiform mole, invasive mole) and non-villous trophoblastic tumors (placental site nodule, exaggerated placental site, placental site tumor, epitheloid trophoblastic tumor, and choriocarcinoma).