Sonographic characteristics of placental site trophoblastic tumor

Pseudo-myometrial thinning in placental site trophoblastic tumors: a case series with multiparametric MRI

PURPOSE

Placental site trophoblastic tumor (PSTT) is a rare form of gestational trophoblastic neoplasm with few previous imaging case reports. We report multiparametric MRI findings in four cases of PSTT with special emphasis on the "pseudo-myometrial thinning" underlying the tumor.

METHODS

We reviewed multiparametric MRI and pathologic findings in four cases of PSTT from four institutions. Signal intensity, enhancement pattern, margins, and location of the tumors were evaluated, and myometrial thickness underlying the tumor and normal myometrial thickness contralateral to the tumor were measured on MRI. The myometrial thickness underlying the tumor was also measured in the resected specimen and compared with the myometrial thickness measured on MRI using the Friedman test.

RESULTS

All tumors showed heterogeneous signal intensity on T1-weighted imaging, T2-weighted imaging (T2WI), and diffusion-weighted imaging. Three of the four tumors had a hypervascular area on dynamic contrast-enhanced (DCE) MRI. A hypointense rim on T2WI and DCE-MRI was seen in all tumors. All tumors protruded into the uterine cavity to varying degrees and extended into the myometrium close to the serosa. The myometrial thickness underlying the tumor measured on MRI (median thickness, 1.2 mm) was significantly thinner than that measured on pathology (median thickness, 9.5 mm) and normal myometrial thickness contralateral to the tumor on MRI (median thickness, 10.3 mm) (P = 0.02), and there was no significant difference between the latter two.

CONCLUSIONS

The thickness of the myometrium underlying the tumor on MRI was approximately one tenth of the thickness on pathology. Thus, the tumors appeared to have almost transmural invasion even when pathologically located within the superficial myometrium. This "pseudo-thinning" of the underlying myometrium and the hypointense rim on MRI could be caused by focal compression of the myometrium by the tumor, possibly due to the fragility of the myometrium at the placental site.

GTN Diagnosis and Staging

Majority of gestational trophoblastic neoplasia (GTN) follows molar pregnancies where diagnosis is mostly based on persistent or rising serum human chorionic gonadotrophin (hCG). Diagnosis of GTN could be based on clinical presentation, serum hCG measurement, imaging, histology, and genotyping. A high index of suspicion in women of reproductive age presenting with abnormal vaginal bleeding or unusual systematic presentation is important. An accurate staging and classification system for GTN is crucial to evaluate the risk and the prognosis of patients, and to optimize treatment. GTN is staged using the International Federation of Gynecology and Obstetrics 2000 staging and the modified World Health Organization prognostic scoring system.

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.

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.

Placental site trophoblastic tumour: five challenges of patient clinical management

Placental site trophoblastic tumour is a rare form of gestational trophoblastic disease accounting for about 1%-2% of all trophoblastic tumours. Diagnosis and management of placental site trophoblastic tumour can be difficult.We report a case of a 30-year-old woman diagnosed with a placental site trophoblastic tumour and identify the challenges in diagnosis and treatment of this rare situation. The presenting sign was abnormal vaginal bleeding that started 3 months after delivery. Image exams revealed an enlarged uterus with a heterogeneous mass, with vesicular pattern, and the increased vascularisation serum human chorionic gonadotropin level was above normal range. The histological diagnosis was achieved through hysteroscopic biopsy. Staging exams revealed pulmonary micronodules. The patient was successfully treated with hysterectomy and chemotherapy. The latest follow-up (37 months after diagnosis) was uneventful, and the patient exhibited no signs of recurrence or metastasis.

ACR Appropriateness Criteria® Gestational Trophoblastic Disease

Gestational trophoblastic disease (GTD), a rare complication of pregnancy, includes both benign and malignant forms, the latter collectively referred to as gestational trophoblastic neoplasia (GTN). When metastatic, the lungs are the most common site of initial spread. Beta-human chorionic gonadotropin, elaborated to some extent by all forms of GTD, is useful in facilitating disease detection, diagnosis, monitoring treatment response, and follow-up. Imaging evaluation depends on whether GTD manifests in one of its benign forms or whether it has progressed to GTN. Transabdominal and transvaginal ultrasound with duplex Doppler evaluation of the pelvis are usually appropriate diagnostic procedures in either of these circumstances, and in posttreatment surveillance. The appropriateness of more extensive imaging remains dependent on a diagnosis of GTN and on other factors. The use of imaging to assess complications, typically hemorrhagic, should be guided by the location of clinical signs and symptoms. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Placental site trophoblastic tumour: the rarest subtype of gestational trophoblastic disease

Placental site trophoblastic tumour (PSTT) is a very rare form of gestational trophoblastic disease that grows slowly, secretes low levels of beta-subunit of human chorionic gonadotropin (β-hCG), presents late-onset metastatic potential and is resistant to several chemotherapy regimens. Here, we report a case of PSTT in a 36-year-old woman who presented with amenorrhea and persistently elevated serum level of β-hCG after a miscarriage. Transvaginal ultrasound revealed a hypovascular ill-defined solid lesion of the uterine fundus and MRI showed a tumour infiltrating the external myometrium with discrete early enhancement and signal restriction on diffusion-weighted imaging. PSTT was suspected, and after endometrial biopsy by hysteroscopy and posterior hysterectomy, microscopic examination allowed the final diagnosis. The level of β-hCG dropped significantly in about a month after surgical treatment. Due to the rarity of PSTT, reporting new cases is crucial to improve the diagnosis and managing of these patients.

A Pictorial Ultrasound Essay of Gestational Trophoblastic Disease

Gestational trophoblastic disease (GTD) includes a wide variety of clinical and histopathologic entities that require prompt identification and definition by the integration of clinical, laboratory, and imaging data. Recently, the role of grayscale ultrasound and spectral and power/color Doppler techniques has become pivotal in the diagnosis, staging, and management of GTD, thanks to both technical improvements and the growing expertise of dedicated operators. The aim of this essay is to summarize the most recent data on the ultrasound and Doppler findings of GTD and to provide a pictorial overview, including useful prognostic and therapeutic implications for clinical practice.

lnc003875/miR-363/EGR1 regulatory network in the carcinoma -associated fibroblasts controls the angiogenesis of human placental site trophoblastic tumor (PSTT)

The rare gestational trophoblastic neoplasia placental site trophoblastic tumor (PSTT) frequently demonstrates a high degree of vascularization, which may facilitate the tumor metastasis. However, the underlying mechanisms remain largely unknown. In the present study, we found that early growth response 1 (EGR1) was highly expressed in the carcinoma-associated fibroblasts (CAFs) of PSTT tissues. Further data showed that miR-363 down-regulated EGR1 expression whereas long non-coding RNA NONHSAT003875 (lnc003875) up-regulated EGR1 expression in PSTT derived CAFs. lnc003875 exerted no effect on miR-363 expression, but it recovered the decrease of EGR1 caused by miR-363 mimic. The conditioned media from PSTT CAFs treated with miR-363 mimic abrogated the tube formation capacity of human umbilical vein endothelial cells (HUVECs), which can be partially restored by lnc003875 over-expression. Moreover, over-expression of EGR1 promoted the secretion of Angiopoietin-1 (Ang-1) in PSTT derived CAFs and improved the tube formation of HUVECs, which could be effectively abrogated by Ang-1 siRNAs. In vivo vasculogenesis assay demonstrated that lnc003875/EGR1 in PSTT derived CAFs promoted the vasculogenesis of HUVECs in C57BL/6 mice. Collectively, these findings indicated that lnc003875/miR-363/EGR1/Ang-1 in CAFs may be crucial for the angiogenesis of PSTT.

A Review on the Pathogenesis and Clinical Management of Placental Site Trophoblastic Tumors

Placental site trophoblastic tumor (PSTT) is a rare type of gestational trophoblastic disease originating from the intermediate trophoblast. Compared with hydatidiform mole, invasive hydatidiform mole and choriocarcinoma, the diagnosis of PSTT is more complicated and lacks specific and sensitive tumor markers. Most PSTT patients demonstrate malignant potential, and the primary treatment of PSTT is hysterectomy. However, metastasis occasionally occurs and even causes death in a small number of PSTT patients. Most PSTT patients are young women hence fertility preservation is an important consideration. The major obstacle for PSTT patient prognosis is chemotherapy resistance. However, the current understanding of the pathogenesis of PSTT and clinical treatment remains elusive. In this review, we summarized the research progress of PSTT in recent years from three aspects: mechanism, clinical presentation, and treatment and prognosis. Well-conducted multi-center studies with sufficient sample sizes are of great importance to better examine the pathological progress and evaluate the prognosis of PSTT patients, so as to develop prevention and early detection programs, as well as novel treatment strategies, and finally improve prognosis for PSTT patients.

Placental site trophoblastic tumor and epithelioid trophoblastic tumor: Clinical and pathological features, prognostic variables and treatment strategy

Placental site trophoblastic tumor [PSTT] and epithelioid trophoblastic tumor [ETT] are the rarest gestational trophoblastic neoplasias, developing from intermediate trophoblast of the implantation site and chorion leave, respectively. PSTT and ETT share some clinical-pathological features, such as slow growth rates, early stage at presentation, relatively low βhCG levels and poor response to chemotherapy. The mortality rate ranges from 6.5% to 27% for PSTT and from 10% to 24.2% for ETT. Advanced stage, long interval between antecedent pregnancy and diagnosis, and presence of clear cells are the independent prognostic variables for PSTT, and they may be similar for ETT. Hysterectomy can represent the only therapy for early disease, whereas adjuvant chemotherapy should be reserved to patients with poor risk factors, such as an interval from the antecedent pregnancy >4 years, deep myometrial invasion or serosal involvement. Few cases of fertility-sparing treatment in young women have been reported. An individualized multidisciplinary approach, including chemotherapy and debulking surgery with abdominal and/or extra-abdominal procedures, is warranted for advanced disease. EP/EMA and TP/TE are the preferred regimens in this setting. Immunohistochemistry has sometimes shown expression of EGFR, VEGF, MAPK, PDGF-R and PD-L1, and therefore investigational studies on biological agents targeting these molecules are strongly warranted for chemotherapy resistant-disease.

Management of placental site trophoblastic tumor: Two case reports

RATIONALE

Placental site trophoblastic tumor (PSTT) is a very rare malignant tumor, belonging to a family of pregnancy-related illnesses, called gestational trophoblastic diseases (GTD). Less than 300 cases of PSTT have been reported in literature, with an incidence of ≈ 1/50,000-100,000 pregnancies representing only 0.23% to 3.00% of all GTDs.

PATIENT CONCERNS

Our report describes 2 additional cases of PSTT outlining their main diagnostic features and the subsequent management. The first case presented contemporary to a persistent hydatidiform mole in a 37-year-old woman, para 2042; whereas the second one originated 5 years after a miscarriage in 43-year-old woman, para 1031 with a previous diagnosis of breast cancer, and shared some features with placental site nodule (PSN), a benign condition.

DIAGNOSIS

The first case had a difficult diagnosis because there was an amenorrhea of 11th week with high serum beta-human chorionic gonadotropin (beta-HCG) and an initial ultrasound image of vesicular mole. After the Dilatation and Curettage, histology confirmed the previous hypothesis. However, the final histology of PSTT was obtained after major surgery. On the contrary, the diagnosis of the second case was less challenging but surprising, thanks to a routine trans-vaginal ultrasound showing a suspicious endometrial thickness positive for PSTT at a subsequent hysteroscopic guided biopsy.

INTERVENTIONS

The treatment consisted of hysterectomy and subsequent follow up. Lymphadenectomy or lymph node sampling were not performed due to the initial stage of the disease.

OUTCOMES

In the first case, there were high values of serum beta-HCG that plummeted after the surgery, whereas in the second one they had been always negative. Hereafter, both went through a follow up with periodic serum oncological markers, imaging studies and clinical evaluation, which have showed negative result for 3 years and 15 months, respectively.

LESSONS

A detailed gynecological ultrasound examination could be extremely helpful to understand the next diagnostic step of echo-guided D&C or hysteroscopic biopsy and for a pre-operative staging assessment. On the contrary, determining the serum beta-HCG's curve is crucial just in case of an initial positive value to pursue clinical evaluation and follow-up. In case of good prognostic factors, the main therapy remains hysterectomy.

The Usefulness of Ultrasound Imaging in Gynecologic Oncology

Pelvic ultrasound examination is the primary imaging modality for evaluating a wide range of female pelvic symptomatology, and is often the first imaging test to detect a gynecologic malignancy. Ultrasound imaging is particularly useful for evaluating the thickness and appearance of the endometrium in patients with abnormal bleeding, and in detecting and characterizing ovarian lesions. This article reviews the ultrasound appearance of gynecologic neoplasms grouped by anatomic site of origin, the ultrasound appearance of select benign pelvic pathology not to be misinterpreted as malignancy, as well as available ultrasound imaging-based guidelines for managing potential gynecologic neoplasms.

Gestational Trophoblastic Disease: Clinical and Imaging Features

Gestational trophoblastic disease (GTD) is a spectrum of both benign and malignant gestational tumors, including hydatidiform mole (complete and partial), invasive mole, choriocarcinoma, placental site trophoblastic tumor, and epithelioid trophoblastic tumor. The latter four entities are referred to as gestational trophoblastic neoplasia (GTN). These conditions are aggressive with a propensity to widely metastasize. GTN can result in significant morbidity and mortality if left untreated. Early diagnosis of GTD is essential for prompt and successful management while preserving fertility. Initial diagnosis of GTD is based on a multifactorial approach consisting of clinical features, serial quantitative human chorionic gonadotropin (β-hCG) titers, and imaging findings. Ultrasonography (US) is the modality of choice for initial diagnosis of complete hydatidiform mole and can provide an invaluable means of local surveillance after treatment. The performance of US in diagnosing all molar pregnancies is surprisingly poor, predominantly due to the difficulty in differentiating partial hydatidiform mole from nonmolar abortion and retained products of conception. While GTN after a molar pregnancy is usually diagnosed with serial β-hCG titers, imaging plays an important role in evaluation of local extent of disease and systemic surveillance. Imaging also plays a crucial role in detection and management of complications, such as uterine and pulmonary arteriovenous fistulas. Familiarity with the pathogenesis, classification, imaging features, and treatment of these tumors can aid in radiologic diagnosis and guide appropriate management. ^©RSNA, 2017.

Placental site trophoblastic tumors and epithelioid trophoblastic tumors: Biology, natural history, and treatment modalities

Placental site (PSTT) and epithelioid trophoblastic tumor (ETT) are rare types of gestational trophoblastic neoplasia (GTN) that arise from intermediate trophoblast. Given that this cell of origin is different from other forms of GTN, it is not surprising that the clinical presentation, tumor marker profile, and treatment paradigm for PSTT and ETT are quite different as well. The mainstay for therapy for stage I PSTT and ETT is hysterectomy with adjuvant chemotherapy reserved for those presenting greater than four years from the antecedent pregnancy. Surgery is also important for metastatic disease. There is no standardized chemotherapy regimen for advanced stage disease but often consists of a platinum-containing combination therapy, usually EMA-EP or TE/TP. Despite its rarity, PSTT and ETT account for a disproportionate percentage of mortality from GTN likely resulting from their relative chemotherapy resistance. Novel therapeutic modalities therefore are needed to improve the outcomes of women with advanced stage or resistant PSTT and ETT.

Historical, morphological and clinical overview of placental site trophoblastic tumors: from bench to bedside

INTRODUCTION

Placental site trophoblastic tumor (PSTT) is a form of gestational trophoblastic disease that originates from the implantation of an intermediate trophoblast. It was described for the first time by Von F. Marchand in 1895 as belonging to chorioepithelioma sui generis, a pathological condition with many variations and a progressive degree of malignancy.

METHODS

We have conducted a literature review in MEDLINE about epidemiology, etiopathogenesis and clinical features of PSTT. Moreover, a case that occurred in our institution was reported.

RESULTS

Our research has highlighted that existing published data about PSTT are not uniform. The number of cases described in the literature has updated and the clinical features of selected "case series" of patients diagnosed with PSTT were showed. The etiopathogenesis was discussed. It was noted that current prognostic factors still allow important information regarding PSTT to be obtained, albeit fragmentary.

CONCLUSIONS

The lack of uniformity in data collection seen so far has limited full knowledge of PSTT. For this reason, we suggest a model (PSTT model) that collects and unifies PSTT evidence as this would be useful to identify worldwide precise prognostic factors, which are still lacking. When PSTT is diagnosed, the proper procedure seems to be total hysterectomy, with sampling of pelvic lymph nodes and ovarian conservation. For advanced-stage diseases, (stage III and IV) a combination of surgery and polychemotherapy is suggested.

Imaging the Endometrium: A Pictorial Essay

Female gynaecologic conditions arising from the endometrium are common and depend on a woman's age, her menstrual history, and the use of medications such as hormone replacement and tamoxifen. Both benign and malignant conditions affect the endometrium. Benign conditions must be distinguished from malignant and premalignant conditions. The most commonly used imaging modality for evaluating the endometrium is pelvic ultrasound with transabdominal and transvaginal techniques. Additional imaging methods include hysterosonography and magnetic resonance imaging. This pictorial essay will review the normal and abnormal appearance of the endometrium and diagnostic algorithms to evaluate abnormal vaginal bleeding and abnormal endometrial thickness.

Placental site trophoblastic tumor: a case report and review of the literature

We present a case of a gravida 1 para 1 woman, who presented with an 11-month history of amenorrhea after cesarean delivery. The patient was taking birth control pills at the time of presentation. She was observed with a slight elevation of serum β-hCG level, an enlarged heterogeneous uterus and hematometra. A biopsy was performed, and the patient was diagnosed with placental site trophoblastic tumor; the patient then underwent surgery. Placental site trophoblastic tumor is the rarest form of gestational trophoblastic disease, derived from intermediate trophoblast cells. It does not have a pathognomonic appearance; therefore, correlation with medical history, as well as results of laboratory tests and pathological analysis is mandatory. It is a relatively chemoresistant tumor, posing considerable therapeutic challenges; patients with localized disease are managed with surgery and those with metastatic disease require additional chemotherapy. Herein, we review the main features of this entity and top differential diagnosis, as the rarity of this tumor is associated with imaging and pathological pitfalls, reinforcing the need for further experience in this field.

Placental site trophoblastic tumor: a case report and review of the literature

Placental site trophoblastic tumor is rare. They represent a rare form of gestational trophoblastic disease. They occur mainly in women who have a history of miscarriage, termination of pregnancy, or even a normal or pathological ongoing pregnancy. The clinical course is unpredictable. This malignancy has different characteristics from other gestational trophoblastic tumors. Following a clinical case that we encountered and treated, we conducted a literary research and review, focusing primarily on prognostic factors and treatment.