Cyclin E and p16 Immunoreactivity in Epithelioid Trophoblastic Tumor???An Aid in Differential Diagnosis

Atypical epithelioid trophoblastic lesion presenting as pseudocyst from the niche in the cesarean scar: A case report and review of the literature

OBJECTIVES

In 2020, the WHO introduced Atypical Placental Site Nodule (APSN) into the new classification of female genital tract tumors, describing it as an intermediate lesion between placental site nodule (PSN) and epithelioid trophoblastic tumor (ETT). Unlike APSN which is typically a nodule, we present a case of a post Cesarean Section (CS) cyst and fistula formation with intermediate pathologic features between PSN and ETT. This type of lesion has earlier been described as "atypical epithelioid trophoblastic lesion". We aim to review similar cases in the literature to gather data on clinic, sonographic and histopathological characteristics.

STUDY DESIGN

We conducted a search on PubMed and Web of Science databases. Given the novelty of the term atypical epithelioid trophoblastic lesion and its lack of validation, we broadened our search to the term 'APSN' including similar cases with unique clinicopathologic features, specifically those involving cyst and fistula formation after CS. Two reviewers independently screened articles and extracted relevant data.

RESULTS

We describe a case of atypical epithelioid trophoblastic lesion presenting as a cystic lesion anterior to a cesarean scar niche. We found eight similar cases in literature. All presented with a cyst and/or fistula that occurred several months, or even years, after CS. Symptoms were vaginal bleeding (2), abdominal pain (2), hematuria (1), amenorrhea (3) and urinary frequency (1). Ki-67 proliferation indices exceeded 12 % in 4/8 (50 %) cases. Necrosis or mitotic figures were not observed in 7/8 (87.5 %) cases. No case displayed signs of recurrence during follow-up (range: 1-12 months).

CONCLUSION

There are only eight cases in literature that display similar sonographic and histopathological features to the case of atypical epithelioid trophoblastic lesion we presented. Further molecular studies focusing on the gene signature of the lesion and gathered data from gestational trophoblastic disease registries could contribute to a better understanding of the origin and behavior of this specific intermediate lesion.

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.

Epithelioid trophoblastic tumor with lung metastasis: A case report and literature review

RATIONALE

Epithelioid trophoblastic tumor (ETT) is an extremely rare variant of gestational trophoblastic neoplasms (GTNs). The biological behavior and therapeutic schedule of ETT remains to be defined which frequently poses diagnostic and therapeutic challenges. Although ETT is a relatively indolent malignancy tumor, the therapeutic efficacy and survival rate decrease significantly when presented with metastases. The lung is the most common site of ETT metastasis.

PATIENT CONCERNS

A 39-year-old female patient presented with irregular vaginal bleeding and slight distention pain in lower abdomen.

DIAGNOSES

The patient was diagnosed ETT with lung metastasis after surgery and immunohistochemical staining.

INTERVENTIONS

A total abdominal hysterectomy plus bilateral salpingectomy and histopathology were performed. The patient received 3 cycles of etoposide, methotrexate, actinomycin-D/etoposide, cisplatin (EMA/EP) regimen chemotherapy after surgery. Due to the presence of lung metastasis, she received pulmonary lesion resection and another cycle of postoperative chemotherapy.

OUTCOMES

The patients showed a good response to treatment initially. However, the patient did not complete the full initial treatment for family reasons and had signs of recurrence after 2.5 months. The serum β-hCG level gradually elevated and the lung imaging showed that the lesion area gradually expanded. After 15 months of follow-up, the patient declined further treatment due to a lack of presenting symptoms.

LESSONS

The diagnosis of ETT should be taken into consideration in patients with abnormal vaginal bleeding and low levels of β-hCG. Patients with metastatic disease should be treated with complete surgical resection and intensive combination chemotherapy to maximize the opportunity for cure. Targeted biological agents might be potential therapeutic strategies for chemotherapy-resistant or recurrent patients.

Placental Chorangiocarcinoma a Specific Histological Pattern of Uncertain Incidence and Clinical Impact: Systematic Review of the Literature

Chorangiocarcinoma is a very rare and misdiagnosed placental neoplasm. The unique morphologic features of the lesion distinguish it from other trophoblastic tumors and vascular abnormalities. We present a systematic review of the literature to provide clarity on chorangiocarcinoma entity and biology. A literature search was carried out in December 2022 using the keywords "Placental chorangiocarcinoma", "Chorangioma", "Placenta", and "Throphoblast proliferation". Articles published from 1988 to 2022 were obtained from Scopus, Google Scholar, and PUBMED. In our review, we examined maternal age, gestational age at the time of delivery, parity, type of pregnancy, placental weight, ultrasound features of the placenta, macroscopic examination and tumor size, microscopic examination, immunostaining, maternal beta-human chorionic gonadotropin, fetal and maternal outcome. Eight manuscripts were detected. They are all case reports. The macroscopic characteristics of the lesions were represented by the presence of a grey-yellow-white color well-demarcated round nodule. Microscopically, all the authors described typical aspects of malignancy as a high rate of mitosis, nuclear atypia and necrotic areas. In some cases, the presence of AE1/AE3 cytoplasmic positivity, p63 nuclear staining, and beta-human chorionic gonadotropin (BHCG) were reported. A good fetal outcome was reported in all cases of newborns with normal birth weight, except one with fetal growth restriction. Maternal outcome was good in all cases except one with maternal lung metastasis three months after delivery. The clinical course has probably underestimated the real incidence of the pathology. Only greater knowledge of its histology and its clinical course will allow us to evaluate the real prevalence of the 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.

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.

Persistent trophoblastic atypia on endocervical curettage found to be an epithelioid trophoblastic Tumor: A case report and review of the literature

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Persistent atypical trophoblastic disease found on endocervical curettage for CIN3.

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Atypia not demonstrated on repeat samplings and no abnormalities on imaging.

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Atypia recurred and final pathology demonstrated epithelial trophoblastic tumor.

We present an unusual case of a 28-year-old female who had atypical trophoblastic proliferation on her endocervical curettage (ECC) performed at the time of a colposcopy. The indication for colposcopy was a Pap smear notable for atypical squamous cells of unknown significance, positive HPV. Initially conservative management was pursued, but given persistent atypia the patient ultimately decided to proceed with definitive management via hysterectomy. Final histologic assessment demonstrated an epithelioid trophoblastic tumor (ETT). This case highlights the unusual scenario of ETT presenting as atypical trophoblastic cells on endocervical curettage and the possible evolution of an atypical placental site nodule into an ETT.

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.

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).

Epithelioid trophoblastic tumor presenting as a Caesarean scar defect: A case report

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Malignancy should be considered as a possible cause of a Caesarean scar defect.

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Gestational trophoblastic neoplasia can be present despite negative hCG.

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Limited evidence on fertility-sparing treatment of epithelioid trophoblastic tumor.

Background

Epithelioid trophoblastic tumor is a rare form of gestational trophoblastic neoplasia. We present the first known case of this rare malignancy presenting as a Caesarean scar defect.

Case

A patient with 3 prior Caesarean sections presented with vaginal bleeding 2 months following management of retained products of conception. Her hCG was negative. She underwent surgical repair of a Caesarean scar defect, and pathology was consistent with epithelioid trophoblastic tumor.

Conclusion

This case highlights the possibility of malignancy presenting to the general gynecologist as a Caesarean scar defect. The diagnosis of gestational trophoblastic neoplasia should always be considered in the differential diagnosis of a patient with postpartum vaginal bleeding. Limited evidence on fertility conserving treatment of epithelioid trophoblastic tumors does not seem favorable.

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.

Epithelioid Trophoblastic Tumor: Expanding the Clinicopathologic Spectrum of a Rare Malignancy

Epithelioid trophoblastic tumor is a malignancy derived from the chorionic laeve-type intermediate trophoblast with sufficient rarity that the vast majority of literature on the topic exists in the form of case reports and small series. Classically, it is regarded as a well-circumscribed tumor with an expansile growth pattern that occurs in reproductive-aged women, usually after a normal pregnancy. However, we recently encountered a case of epithelioid trophoblastic tumor with aggressive spread throughout the abdomen and pelvis in a 68-yr-old female presenting 30 yr after her last delivery. Although to our knowledge this is the first report in a postmenopausal patient to be confirmed by molecular analysis of short tandem repeats, there are multiple similar case reports spanning a variety of clinical settings that deviate from the original description. We therefore sought to synthesize the clinicopathologic data among the available reports in the English literature, with emphasis on pathologic findings. While the overarching themes are largely unchanged, this series of 77 patients reveals a broader spectrum of disease and highlights frequent misdiagnosis. Here we present a clinicopathologic update on this rare entity, with emphasis on a practical approach to diagnosis.

Management and prognostic factors of epithelioid trophoblastic tumors: Results from the International Society for the Study of Trophoblastic Diseases database

OBJECTIVE

Epithelioid Trophoblastic Tumor (ETT) is an extremely rare form of Gestational Trophoblastic Neoplasia (GTN). Knowledge on prognostic factors and optimal management is limited. We identified prognostic factors, optimal treatment, and outcome from the world's largest case series of patients with ETT.

METHODS

Patients were selected from the international Placental Site Trophoblastic Tumor (PSTT) and ETT database. Fifty-four patients diagnosed with ETT or mixed PSTT/ETT between 2001 and 2016 were included. Cox regression analysis was used to identify prognostic factors for overall survival (OS).

RESULTS

Forty-five patients with ETT and 9 patients with PSTT/ETT were included. Thirty-six patients had FIGO stage I and 18 had stages II-IV disease. Patients were treated with surgery (n = 23), chemotherapy (n = 6), or a combination of surgery and chemotherapy (n = 25). In total, 39 patients survived, including 22 patients with complete sustained hCG remission for at least 1 year. Patients treated with surgery as first line treatment had early-stage disease and all survived. Most patients treated with chemotherapy with or without surgery had FIGO stages II-IV disease (55%). They underwent multiple lines of chemotherapy. Eleven of them did not survive. Interval since antecedent pregnancy and FIGO stage were prognostic factors of OS (p = 0.012; p = 0.023 respectively).

CONCLUSIONS

Advanced-stage disease and an interval of ≥48 months since the antecedent pregnancy are poor prognostic factors of ETT. Surgery seems adequate for early-stage disease with a shorter interval. Advanced-stage disease requires a combination of treatment modalities. Because of its rarity, ETT should be treated in a centre with experience in GTN.

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.

Two cases of epithelioid trophoblastic tumors in postmenopausal women

OBJECTIVE

Epithelioid trophoblastic tumor is a rare gestational trophoblastic neoplasm usually presenting in women of reproductive age, with a history of a prior gestational event. Its presentation in postmenopausal women is extremely rare. Immunohistochemical staining is a helpful aid to distinguish epithelioid trophoblastic tumor from other gestational trophoblastic neoplasms. Correct diagnosis is crucial for clinical management that can vary according to the type of gestational trophoblastic neoplasm.

METHODS

We report the case of a 63-year-old postmenopausal woman 33 years after her last full-term pregnancy and another case of a 57-year-old postmenopausal woman who had had a first-trimester abortion 30 years previously as her last gestational event, both presenting cervical epithelioid trophoblastic tumors. In both cases, immunohistochemistry played an important role in differentiating this entity from other gestational trophoblastic neoplasms. Surgery was the primary treatment in both cases. The first patient remained disease-free and died 5 years later due to a rectal adenocarcinoma, and the second patient remains disease-free at publication.

RESULTS

In both cases, the hysterectomy specimen confirmed the presence of two large epithelioid trophoblastic tumors arising in the endocervix and lower uterine segment with no extrauterine disease. Nuclear positivity for p63 allowed differentiation from a placental site trophoblastic tumor. The Ki67 proliferative index was 20% and 35%, respectively.

CONCLUSIONS

Epithelioid trophoblastic tumors may occur a long time after a prior gestational event and should even be excluded in postmenopausal women with uterine masses. Immunohistochemical staining is helpful to make the differential diagnosis with other gestational trophoblastic neoplasms.

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.

Insights into dovetailing GTD and Cancers

Gestational trophoblastic diseases (GTD) encompass a group of placental tumors which mostly arise due to certain fertilization defects, resulting in the over-proliferation of trophoblasts. The major characteristic of this diseased state is that β-hCG rises up manifold than that is observed during pregnancy. The incidence of GTD when analyzed on a global scale, figures out that there is a greater risk in South-East Asia, the reason of which remains unclear. An insight into any possible correlation of GTD incidence with cancers, other than choriocarcinoma, is being attempted here. Also, we review the recent developments in research on the molecular etiopathology of GTD. This review would render a wider eye towards a new paradigm of thoughts to connect GTD and breast cancer, which has not been into the picture till date.

Practical issues in uterine pathology from banal to bewildering: the remarkable spectrum of smooth muscle neoplasia

Among mesenchymal tumors of the uterus, smooth muscle neoplasms are most common. The wide morphologic spectrum, especially within the category of leiomyomas, is responsible for diagnostic problems more frequently with leiomyosarcoma (including mitotically active, apoplectic, and leiomyoma with bizarre nuclei) but also with endometrial stromal tumors. In the former scenario, clinical information, gross appearance as well as strict utilization of morphologic criteria including cytologic atypia, mitotic activity, and tumor cell necrosis are clues in establishing the correct diagnosis. It is important to keep in mind that mitotic rate thresholds vary for the different subtypes of leiomyosarcoma. Of note, p16 should be used with caution in supporting a diagnosis of leiomyosarcoma as it is often positive in leiomyomas with bizarre nuclei and leiomyomas with apoplectic change (in the latter most frequently and more intense near areas of necrosis). MED12 mutations have also a very limited role in this differential diagnosis. Endometrial stromal tumors are by far, less common than smooth muscle tumors, but can be confused with leiomyosarcomas if they are associated with an undifferentiated uterine sarcoma and the low-grade component is overlooked or they have a myxoid/fibroblastic morphology. The differential diagnosis may be confounded if the latter is associated with a high-grade endometrial stromal sarcoma. It is important to highlight that CD10 is not a reliable marker in these differentials and should be used as a part of a panel of antibodies that also includes desmin and h-caldesmon. Two other recently categorized tumors in the uterus that merit special mention are PEComa and inflammatory myofibroblastic tumor as they enter in the differential diagnosis of smooth muscle tumors. PEComa may be part of the tuberous sclerosis syndrome and may show either a predominantly epithelioid or spindle morphology or combination thereof. Rarely, it may contain melanin pigment. There is variable positivity for HMB-45, MelanA, MiTF, and CathepsinK, and some tumors have been shown to express TFE-3 especially when associated with "clear cell" morphology. Patients with adverse outcome have tumors with ≥2 of the following features: ≥5 cm, infiltration, high-grade cytologic features, mitotic rate ≥1/50 high-power fields, necrosis, or lymphovascular invasion. Inflammatory myofibroblastic tumor is important to recognize as it often mimics myxoid smooth muscle tumors, either benign or malignant. The presence of an associated lymphoplasmacytic infiltrate should alert to that possibility and ALK studies (immunostain or FISH) are helpful in establishing this diagnosis. These tumors can behave in a malignant manner if large, associated with abundant myxoid change, brisk mitotic rate or show tumor cell necrosis.

CCNE1 amplification is associated with aggressive potential in endometrioid endometrial carcinomas

The clinicopathological significance of amplification was investigated of the gene encoding cyclin E (CCNE1) and we assessed whether CCNE1 was a potential target in endometrioid endometrial carcinomas. CCNE1 amplification and CCNE1 or F-box and WD repeat domain-containing 7 (FBXW7) expression in endometrial endometrioid carcinoma was assessed by immunohistochemistry and fluorescence in situ hybridization. CCNE1 knockdown by small interfering RNA (siRNA) was used to assess the CCNE1 function. The results showed that CCNE1 amplification was present in 9 (8.3%) of 108 endometrial carcinomas. CCNE1 amplification was correlated with high histological grade (Grade 3; P=0.0087) and lymphovascular space invasion (P=0.0258). No significant association was observed between CCNE1 amplification and FIGO stage (P=0.851), lymph node metastasis (P=0.078), body mass index (P=0.265), deep myometrial invasion (P=0.256), menopausal status (P=0.289) or patient age (P=0.0817). CCNE1 amplification was significantly correlated with shorter progression-free and overall survival (P=0.0081 and 0.0073, respectively). CCNE1 protein expression or loss of FBXW7 expression in endometrial endometrioid carcinoma tended to be correlated with shorter progression-free and overall survival; however, this difference was not statistically significant. Multivariate analysis showed that CCNE1 amplification was an independent prognostic factor for overall survival but not for progression-free survival (P=0.0454 and 0.2175, respectively). Profound growth inhibition was observed in siRNA-transfected cancer cells with endogenous CCNE1 overexpression compared with that in cancer cells having low CCNE1 expression. CCNE1 amplification was independent of p53, HER2, MLH1 and ARID1A expression but dependent on PTEN expression in endometrial carcinomas. These findings indicated that CCNE1 amplification was critical for the survival of endometrial endometrioid carcinomas. Furthermore, the effects of CCNE1 knockdown were dependent on the CCNE1 expression status, suggesting that CCNE1-targeted therapy may be beneficial for patients with endometrial endometrioid carcinoma having CCNE1 amplification.

Atypical placental site nodule (APSN) and association with malignant gestational trophoblastic disease; a clinicopathologic study of 21 cases

The WHO Classification of Gestational Trophoblastic Tumors classifies placental site nodule (PSN) as a benign tumor-like trophoblastic neoplasm. Cases of PSN with atypical features were described [atypical placental site nodule (APSN)] and we started registering APSN in our unit in 2005. The aim of this study is to present our initial experience with these lesions. The Trophoblastic Disease Unit database was searched to identify all patients who were either referred with, or on review were diagnosed with, APSN from September 2005 to May 2013. Case notes and the pathology findings for these patients were retrieved and reviewed. A total of 21 cases of APSN were included, 3 of which were associated with gestational trophoblastic neoplasm on follow-up or review. Malignant gestational trophoblastic disease was associated with 3/21 (14%) cases of APSN, either concurrently or developing/manifesting within 16 mo of APSN diagnosis. None of these patients had raised serum hCG levels either at presentation or follow-up. Presence of APSN should indicate a thorough clinical and radiologic investigation and follow-up if diagnosed on curettage specimens. With increased recognition of this entity and corresponding larger series with longer follow-up, more accurate patient counseling will be possible.

Atypical postcesarean epithelioid trophoblastic lesion with cyst formation: a case report and literature review

We report an extremely rare case of atypical postcesarean epithelioid trophoblastic lesion with cyst formation. A 41-year-old Chinese woman presented with lower abdominal pain and menstrual disorder. Her serum human chorionic gonadotropin (hCG) was low (0.373 IU/L), and her urine hCG was negative. Ultrasound images showed a 3.7×2.8×2.5 cm(3) mass on the surface of the lower uterine segment, and a laparoscopy indicated a cystic mass in the serosal surface of the lower uterine segment. Histology indicated a cystic lesion consisting of epithelioid trophoblastic cells with an intermediate pattern between a classical placental site nodule and an epithelioid trophoblastic tumor; thus, the term atypical postcesarean epithelioid trophoblastic lesion with cyst formation was appropriate. As in atypical placental site nodule, serum hCG monitoring after treatment is necessary.

GATA-3 expression in trophoblastic tissues: an immunohistochemical study of 445 cases, including diagnostic utility

Immunohistochemical expression of GATA-3 is seen predominantly in non-neoplastic bladder and breast epithelium and their respective carcinomas; however, data on expression in normal and lesional trophoblastic tissues are limited. Immunohistochemical staining for GATA-3 was assessed in a range of normal/lesional trophoblastic tissues and tumors in the differential diagnosis (n=445), including nonmolar products of conceptions/second and third trimester placentas/ectopic pregnancies, hydatidiform moles, placental site nodules, normal/exaggerated implantation sites, choriocarcinomas, epithelioid trophoblastic tumors, placental site trophoblastic tumors, atypical smooth muscle tumors (including leiomyosarcoma), and cervical and pulmonary squamous cell carcinomas. The extent of expression (0 to 4+) and intensity (weak to strong) were recorded. All cases with developing trophoblast/non-neoplastic trophoblastic proliferation and 81% of trophoblastic neoplasms were positive. Of all non-neoplastic trophoblast cell types, expression was observed in cytotrophoblast in 89% of cases, syncytiotrophoblast in 50%, intermediate trophoblast in 100%, and villous trophoblastic columns in 100%. Increasing gestational age was associated with a decrease in extent/intensity of expression in non-neoplastic cytotrophoblast and syncytiotrophoblast, whereas intermediate trophoblast maintained diffuse and strong expression from early to late gestation (P<0.0001). Eighty-nine percent of normal/exaggerated implantation sites showed 3+ or 4+ expression, whereas staining in 55% of placental site nodules was 1+ or 2+. Staining for GATA-3 was present in 78% of choriocarcinomas, 95% of epithelioid trophoblastic tumors, and 71% of placental site trophoblastic tumors. Although the number of choriocarcinomas and placental site trophoblastic tumors that showed a spectrum of expression ranging from negative to diffuse was relatively evenly distributed, 81% of epithelioid trophoblastic tumors had 3+ or 4+ staining. None of the atypical smooth muscle tumors and 3% of squamous cell carcinomas were positive, all of which exhibited weak staining. We conclude that GATA-3 is frequently expressed in normal and lesional trophoblastic tissues. It is also differentially expressed in intermediate trophoblast and cytotrophoblast/syncytiotrophoblast, which varies according to time during pregnancy. This study expands the spectrum of neoplasms known to express GATA-3. Thus, recognition of expression in trophoblastic tumors is important, because it can present a diagnostic pitfall in the assessment of suspected metastatic bladder or breast carcinomas involving the gynecologic tract. In the evaluation of diagnostically problematic tumors for which trophoblastic neoplasms are in the differential diagnosis, such as leiomyosarcoma and squamous cell carcinoma, GATA-3 can be included as part of an immunohistochemical panel particularly when other trophoblastic markers are either not available or yield ambiguous results.

Epithelioid trophoblastic tumor: report of two cases in postmenopausal women with literature review and emphasis on cytological findings

BACKGROUND

Epithelioid trophoblastic tumor (ETT) is a rare gestational trophoblastic neoplasm of intermediate trophoblasts. It was first described by Shih and Kurman [Am J Surg Pathol 1998;22:1393-1403] who outlined its clinicopathologic characteristics in 14 cases, establishing it as a distinct entity of gestational trophoblastic tumors. It represents 1.39% of all gestational trophoblastic diseases. Most cases are reported in reproductive-age women following a prior gestation with a time interval between 2 weeks and 30 years. ETT is extremely rare in postmenopausal women. It is commonly misdiagnosed as a squamous cell carcinoma (SCC), poorly differentiated carcinoma or another gestational trophoblastic tumor. Limited data is available regarding its cytological features on Pap smears.

CASES

We report 2 cases of uterine ETT occurring in postmenopausal women. In both cases, an initial diagnosis of an SCC and a poorly differentiated carcinoma was rendered. We highlight the features of ETT helpful in differentiating it from other mimickers with emphasis on rarely reported cytological features of this neoplasm.

CONCLUSION

ETT is a rare tumor with characteristic cytological features, but is commonly confused with SCC. A high index of suspicion is needed to make the correct diagnosis or to raise the consideration of ETT, especially in cases with an increased β-human chorionic gonadotropin.

Transformation of a post-cesarean section placental site nodule into a coexisting epithelioid trophoblastic tumor and placental site trophoblastic tumor: a case report

Placental site nodules (PSNs) and epithelioid trophoblastic tumors (ETTs) respectively represent non-neoplastic and neoplastic lesions of chorionic-type intermediate trophoblasts (ITs). Many patients with a PSN have a history of a cesarean section (CS) or therapeutic abortion. Recent evidence shows that a PSN may progress to an ETT. Herein, we describe a coexisting ETT and placental site trophoblastic tumor (PSTT) intimately associated with PSNs in the post-cesarean lower uterine segment of a 41-year-old woman. The patient presented with abnormal vaginal bleeding 1 year after a cesarean delivery for her most recent pregnancy. We speculated that the neoplasms had transformed from PSNs, the formation of which was related to faulty expulsion of the placental tissue or abnormal colonization of chorionic-type ITs during the CS. Neoplastic trophoblastic cells derived from PSNs displayed differentiation plasticity toward chorionic-type ITs and implantation site ITs that were respectively constituted of an ETT and PSTT.

VIRTUAL SLIDES

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1597949195882123.

Coexistence of placental site nodule and cervical squamous carcinoma in a 72-year-old woman

We report a unique case of the coexistence of cervical cancer and placental site nodule (PSN) in a 72-year-old multiparous woman presenting with vaginal bleeding. She had undergone tubal sterilization 30 years before. On admission, she had profuse vaginal bleeding, and a bulky cervical mass was seen on vaginal examination. Histology revealed the coexistence of a moderately differentiated invasive squamous cell carcinoma with a PSN in its stroma. Its immunohistochemistry revealed characteristic phenotypes for both lesions--the squamous carcinoma was strongly positive for p16. The intermediate trophoblasts of the PSN showed a diffuse positivity for CAM 5.2, human placental lactogen, CD10, and α-inhibin and, focally, for human chorionic gonadotropin. This is the first report on the coexistence of these 2 lesions in an elderly postmenopausal patient and demonstrates that PSN can be found after the menopause as an unexpected lesion in this age group, mimicking various cervical malignancies.

Atypical epithelioid trophoblastic lesion with cyst and fistula formation after a cesarean section: a rare form of gestational trophoblastic disease

We report 2 unusual cases of gestational trophoblastic disease from chorionic-type intermediate trophoblastic cells after a Cesarean section. A 32-year-old woman presented with a 2-year history of vaginal bleeding, while a 41-year-old woman presented with a pelvic mass. Both patients had cystic lesions with a fistula formation beneath their Cesarean scars in the anterior uterine isthmus. Microscopically, both lesions were lined with multiple layers of intermediate trophoblastic cells without penetration into the surrounding myometrium, endometrium, or blood vessels. The trophoblastic cells were generally bland. However, a subset of trophoblastic cells showed large, hyperchromatic nuclei in some areas. The trophoblastic cells were p63 positive and human placental lactogen negative. The Ki67 indexes were 12.7% and 8.6%, respectively. We propose their description as atypical epithelioid trophoblastic lesions with cyst and fistula formation after a Cesarean section.

Epithelioid trophoblastic tumor: a case report and review of the literature

Epithelioid trophoblastic tumor (ETT) is a rare gestational trophoblastic tumor. Cases of ETT present as abnormal vaginal bleeding in women of reproductive age, with low human chorionic gonadotropin (hCG) levels. ETT can be a sequela of any gestational event and can present in both intrauterine and extrauterine sites. Metastasis and death have been reported. We present a case of a 44-year-old female incidentally diagnosed with ETT following laparoscopic-assisted vaginal hysterectomy. Postoperative evaluation for metastatic disease was negative. The patient has been closely followed and remains disease free 8 months postoperatively. ETT presents a diagnostic challenge due to its rarity and histologic resemblance to other pathologies. ETT is relatively chemoresistant and managed surgically. Misdiagnosis delays effective treatment and affects survival.

Downregulation of the tumor-suppressor miR-16 via progestin-mediated oncogenic signaling contributes to breast cancer development

Introduction

Experimental and clinical evidence points to a critical role of progesterone and the nuclear progesterone receptor (PR) in controlling mammary gland tumorigenesis. However, the molecular mechanisms of progesterone action in breast cancer still remain elusive. On the other hand, micro RNAs (miRNAs) are short ribonucleic acids which have also been found to play a pivotal role in cancer pathogenesis. The role of miRNA in progestin-induced breast cancer is poorly explored. In this study we explored progestin modulation of miRNA expression in mammary tumorigenesis.

Methods

We performed a genome-wide study to explore progestin-mediated regulation of miRNA expression in breast cancer. miR-16 expression was studied by RT-qPCR in cancer cell lines with silenced PR, signal transducer and activator of transcription 3 (Stat3) or c-Myc, treated or not with progestins. Breast cancer cells were transfected with the precursor of miR-16 and proliferation assays, Western blots or in vivo experiments were performed. Target genes of miR-16 were searched through a bioinformatical approach, and the study was focused on cyclin E. Reporter gene assays were performed to confirm that cyclin E 3'UTR is a direct target of miR-16.

Results

We found that nine miRNAs were upregulated and seven were downregulated by progestin in mammary tumor cells. miR-16, whose function as a tumor suppressor in leukemia has already been shown, was identified as one of the downregulated miRNAs in murine and human breast cancer cells. Progestin induced a decrease in miR-16 levels via the classical PR and through a hierarchical interplay between Stat3 and the oncogenic transcription factor c-Myc. A search for miR-16 targets showed that the CCNE1 gene, encoding the cell cycle regulator cyclin E, contains conserved putative miR-16 target sites in its mRNA 3' UTR region. We found that, similar to the molecular mechanism underlying progestin-modulated miR-16 expression, Stat3 and c-Myc participated in the induction of cyclin E expression by progestin. Moreover, overexpression of miR-16 abrogated the ability of progestin to induce cyclin E upregulation, revealing that cyclin E is a novel target of miR-16 in breast cancer. Overexpression of miR-16 also inhibited progestin-induced breast tumor growth in vitro and in vivo, demonstrating for the first time, a role for miR-16 as a tumor suppressor in mammary tumorigenesis. We also found that the ErbB ligand heregulin (HRG) downregulated the expression of miR-16, which then participates in the proliferative activity of HRG in breast tumor cells.

Conclusions

In this study, we reveal the first progestin-regulated miRNA expression profile and identify a novel role for miR-16 as a tumor suppressor in progestin- and growth factor-induced growth in breast cancer.

Novel molecular markers of malignancy in histologically normal and benign breast

To detect the molecular changes of malignancy in histologically normal breast (HNB) tissues, we recently developed a novel 117-gene-malignancy-signature. Here we report validation of our leading malignancy-risk-genes, topoisomerase-2-alpha (TOP2A), minichromosome-maintenance-protein-2 (MCM2) and “budding-uninhibited-by-benzimidazoles-1-homolog-beta” (BUB1B) at the protein level. Using our 117-gene malignancy-signature, we classified 18 fresh-frozen HNB tissues from 18 adult female breast cancer patients into HNB-tissues with low-grade (HNB-LGMA; N = 9) and high-grade molecular abnormality (HNB-HGMA; N = 9). Archival sections of additional HNB tissues from these patients, and invasive ductal carcinoma (IDC) tissues from six other patients were immunostained for these biomarkers. TOP2A/MCM2 expression was assessed as staining index (%) and BUB1B expression as H-scores (0–300). Increasing TOP2A, MCM2, and BUB1B protein expression from HNB-LGMA to HNB-HGMA tissues to IDCs validated our microarray-based molecular classification of HNB tissues by immunohistochemistry. We also demonstrated an increasing expression of TOP2A protein on an independent test set of HNB/benign/reductionmammoplasties, atypical-ductal-hyperplasia with and without synchronous breast cancer, DCIS and IDC tissues using a custom tissue microarray (TMA). In conclusion, TOP2A, MCM2, and BUB1B proteins are potential molecular biomarkers of malignancy in histologically normal and benign breast tissues. Larger-scale clinical validation studies are needed to further evaluate the clinical utility of these molecular biomarkers.

MEK inhibition suppresses cell invasion and migration in ovarian cancers with activation of ERK1/2

The extracellular-regulated kinase (ERK) signaling pathway plays an important role in regulating the malignant potential of a cancer cell. However, the effect of ERK signaling on cancer metastasis is not clearly understood. In the present study, we examined the status of ERK activation in 88 ovarian carcinomas in order to clarify the clinicopathological and prognostic significance of phosphorylated ERK1/2 (p-ERK1/2). p-ERK1/2 expression was identified in 37 (42%) of 88 ovarian carcinomas. There was no significant correlation between p-ERK1/2 expression and any of the clinicopathological factors tested. No significant correlation between p-ERK1/2 expression and overall survival was found in patients with ovarian carcinoma treated with platinum and taxane chemotherapy (P=0.426). Next, to clarify the role of ERK1/2 activation in ovarian cancers, we inactivated ERK1/2 in ovarian cancer cells using the MEK inhibitor, CI-1040, which prevents ERK1/2 activation. Based on simulated wound healing and invasion chamber assays, we found that the motility and invasion of ES2 and MPSC1 cells with p-ERK1/2 were significantly reduced (P<0.01) after treatment with CI-1040. By contrast, CI-1040 did not have any effect on KF28 cells, which were negative for p-ERK1/2. Twist was down-regulated simultaneously with p-ERK1/2 following treatment of ES2 and MPSC1 cells with CI-1040. Immunohistochemistry of ovarian carcinoma tissue revealed that the increased expression of p-ERK1/2 significantly correlated with Twist expression (P<0.01). The findings in this study provide new insight into the biological role of ERK signaling in ovarian carcinomas. Additionally, our observations have an important therapeutic implication for patients with ovarian cancers that express p-ERK1/2 as these patients may potentially benefit from CI-1040 therapy.

The expression and diagnostic utility of p63 in the female genital tract

p63 plays a key role in epithelial development in various organs, being expressed in myoepithelial cells and in basal cells of stratified epithelia. In the female genital tract, p63 is expressed in the basal and parabasal cells of mature cervical, vaginal and vulval squamous epithelium, and also in cervical reserve cells at the transformation zone and in immature metaplastic and atrophic cervical squamous epithelium. In this review, the diagnostic utility of p63 immunohistochemical staining in various pathologic scenarios within the female genital tract is discussed. Cervical microglandular hyperplasia is p63 positive with a characteristic subcolumnar location due to expression in reserve cells. There is increased expression in cervical intraepithelial neoplasia, in accordance with the degree of dysplasia. One of the most useful applications of p63 is in the evaluation of problematic cervical carcinomas; most squamous carcinomas exhibit diffuse nuclear immunoreactivity whereas most adenocarcinomas and neuroendocrine carcinomas are negative or focally positive. In conjunction with neuroendocrine markers, p63 is useful in distinguishing between a squamous carcinoma and a small cell or large cell neuroendocrine carcinoma. In the normal endometrium, a population of p63-positive cells is present which may act as a stem cell population and which is increased in various forms of metaplasia. Placental site nodule and epithelioid trophoblastic tumor (lesions derived from chorionic-type intermediate trophoblast) are usually p63 positive whereas placental site reaction and placental site trophoblastic tumor (lesions derived from implantation site intermediate trophoblast) are usually negative; thus, p63 may be useful in the diagnostic algorithm of trophoblastic lesions. p63 positivity in ovarian epithelial tumors is uncommon and largely restricted to squamous and transitional neoplasms, including benign and borderline Brenner tumor. p63 is also positive in cervical transitional metaplasia, Walthard rests, vulval Paget disease secondary to an underlying urothelial malignancy, tubulosquamous polyp of the vagina, and ectopic prostatic tissue in the cervix.

Expression of a BTB/POZ protein, NAC1, is essential for the proliferation of normal cyclic endometrial glandular cells and is up-regulated by estrogen

PURPOSE

The purpose of this study was to investigate the expression and localization of NAC1, a member of the BTB/POZ gene family in the human cyclic endometrium.

EXPERIMENTAL DESIGN

NAC1 expression in normal cyclic endometrium was assessed by immunohistochemistry, and data on clinical variables were collected by retrospective chart review. To elucidate the molecular mechanisms of NAC1 expression in the normal endometrium endometrial carcinoma cell lines (Ishikawa, HHUA; ER+, PR+) and primary cultured normal endometria were tested in a sex steroid induction assay and a NAC1 knockdown assay using siRNA.

RESULTS

Expression of NAC1 in glandular cells was significantly higher in the early and mid proliferative phases than in the other menstrual phases. Both NAC1 RNA and protein expression were up-regulated by treatment with 10 nmol/L 17beta-Estradiol (E2) in Ishikawa, HHUA and primary cultured normal endometrial cells. The estrogen receptor antagonist ICI 182,780 significantly attenuated E2-induced NAC1 expression. NAC1 gene knockdown inhibited cell growth and induced apoptosis in Ishikawa, HHUA, and normal endometria, all of which expressed NAC1. Furthermore, NAC1 siRNA significantly abrogated estrogen-driven cellular proliferation in Ishikawa, HHUA, and primary cultured normal endometrial cells, whereas the control siRNA had no effect on cell growth in any of these cells.

CONCLUSIONS

These findings suggest that NAC1 is functionally involved in E2-induced cell growth of the normal endometrial glandular cells. Because NAC1 is thought to have oncogenic potential, the current findings may provide new insight into the mechanism of estrogen induced endometrial carcinogenesis.

Immunohistochemical studies of trophoblastic tumors

Although intermediate trophoblastic tumors (ITTs) are rare forms of trophoblastic neoplasia, their recognition is important as they require distinct therapeutic approaches. We have noted mixed trophoblastic tumors, with a combination of placental site trophoblastic tumor and epithelioid trophoblastic tumor patterns within the same case, and more frequently a combination of ITT with choriocarcinoma, which can create difficulty in the classification of these tumors. The distinction of the ITTs from choriocarcinoma is important because ITTs do not respond as well to chemotherapy as choriocarcinoma. In addition, ITTs can be confused with a variety of malignant neoplasms, the most common of which is poorly differentiated carcinoma of the cervix. Immunohistochemistry is one means of identifying trophoblastic tumors and of distinguishing them from other entities. We investigated the immunophenotype of 15 ITTs, 11 choriocarcinomas, and 10 primary cervical carcinomas using a panel of human placental lactogen, p63, CK5/6, CK18, human chorionic gonadotropin (hCG), human leukocyte antigen (HLAG), Mel-CAM, (CD146) carcinoembryonic antigen, CD10, inhibin, p16, and pan-keratin. CD10 was positive in all the cases of ITT and choriocarcinoma. HLA-G expression was present in 93% of ITTs and all choriocarcinoma cases. hCG was positive in 87% of ITTs and 100% of choriocarcinomas. We concluded that a panel consisting of HLA-G, CD10, and hCG can be very helpful in the identification of the ITTs. Adding CK5/6 to these markers can help to differentiate ITT from primary cervical carcinoma. However, the distinction of ITTs from choriocarcinoma cannot be accomplished on immunohistochemical studies, as they have similar immunophenotypes.

Application of immunohistochemistry to gynecologic pathology

CONTEXT

A large variety of tumors and lesions arise in the female genital tract. Although the majority of these can be correctly recognized on routine hematoxylin-eosin-stained slides, occasional cases present a diagnostic challenge. Immunohistochemical stains are extremely useful in resolving many of these problematic cases. As the knowledge in this area is constantly expanding, it is useful to have this updated information in a review form for easy access.

OBJECTIVE

To present our current knowledge of immunohistochemistry of the lesions of the female genital tract in a readily accessible form.

DATA SOURCES

The review is based on previously published articles on this topic.

CONCLUSIONS

Immunohistochemical stains help in reaching a conclusive diagnosis in a variety of problematic lesions seen in gynecologic pathology. As in any other system, immunohistochemical findings need to be interpreted in light of the clinical history and morphologic findings.

Gestational trophoblastic neoplasia—pathogenesis and potential therapeutic targets

Gestational trophoblastic neoplasia comprises a unique group of human neoplastic diseases that derive from fetal trophoblastic tissues and represent semiallografts in patients. This group is composed of choriocarcinoma, placental-site trophoblastic tumour, and epithelioid trophoblastic tumour, and many forms are derived from the precursor lesions, hydatidiform moles. Although most patients with gestational trophoblastic neoplasia are cured by chemotherapy and tumour resection, some patients suffer from metastatic diseases that are refractory to conventional chemotherapy. Therefore, new therapeutic regimens are needed to reduce the toxic effects associated with current chemotherapy and to salvage the occasional non-operable patients with recurrent and chemoresistant disease. Until the fundamental biology of gestational trophoblastic neoplasia becomes more clearly understood, development of a new treatment will remain empirical. This review will briefly summarise the recent advances in understanding the molecular aetiology of this group of diseases and highlight the molecules that can be potentially used for therapeutic targets to treat metastatic gestational trophoblastic neoplasia.