Epithelioid trophoblastic tumor: comparative genomic hybridization and diagnostic DNA genotyping

Clinicopathological characteristics and oncologic outcomes of patients with gestational trophoblastic neoplasia manifesting as isolated pulmonary lesions

OBJECTIVE

To elucidate the clinicopathological characteristics and oncological outcomes of a special group of patients with gestational trophoblastic neoplasia (GTN) initially presenting with isolated lung lesions, elevated human chorionic gonadotropin (hCG) levels, and unobserved pelvic lesions.

METHODS

Overall, 2358 patients with GTN treated at our hospital between 2000 and 2023 were retrospectively reviewed, and 40 patients were evaluated. The demographic characteristics, clinicopathological features, treatment data, and follow-up information of each patient were collected. The primary outcome was progression free survival. Kaplan-Meier analysis and univariate and multivariate Cox proportional hazard analyses were used to identify the risk factors.

RESULTS

Among the 40 patients, 95.0 % had solitary lung lesions, with a median size of 1.9 cm. Moreover, 72.5 % of patients were pathologically confirmed as epithelioid trophoblastic tumors (ETT). During a median follow-up period of 53.5 months (range, 2-143), 11 patients experienced recurrence, including all patients who received chemotherapy alone as the initial treatment, and no death was observed. Relapse treatment involved lung segmentectomy and lobectomy combined with chemotherapy and immunotherapy. Univariate and multivariate Cox analyses identified comparing with surgery±chemotherapy, chemotherapy alone as the initial treatment (hazard ratio [HR] =7.738, 95 % confidence interval [CI] 1.698-35.269, P = 0.008) as independent risk factor for recurrence.

CONCLUSIONS

In patients with a history of pregnancy exhibiting isolated pulmonary lesions, elevated hCG levels (mostly <1000 mIU/mL), and unobserved pelvic lesions, ETT should be considered first. Surgical resection of lung lesion is crucial for optimal management. When chemotherapy is considered, multidrug regimen is recommended.

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.

Mixed Gestational Trophoblastic Tumors-Challenging Clinicopathological Presentations

Mixed gestational trophoblastic tumors are exceptionally rare and have variable clinicopathological presentations. We report 3 such tumors with different combinations of choriocarcinoma (CC), placental site trophoblastic tumor (PSTT), and epithelioid trophoblastic tumor (ETT). The patients' age ranged from 38 to 44 years. Mixed trophoblastic tumor was not considered at the initial diagnosis and all 3 tumors were proven of gestational origin by DNA genotyping. Patient #1 presented with serum human chorionic gonadotropin (hCG) of 97 mIU/mL and a 5.6-cm cervical mass that was initially interpreted as PSTT on biopsy. Hysterectomy revealed a mixed PSTT (60%) and ETT (40%) with extrauterine metastases of only the ETT component. The tumor recurred 15 months after a multiagent chemotherapy and was tested positive for programmed death-ligand 1. The patient received immune checkpoint inhibitor therapy and remained disease-free after 24 months. Patient #2 presented with vaginal bleeding and serum hCG of 46,458 mIU/mL. An endometrial biopsy was interpreted as CC. Recurrence developed in the uterus and lung after methotrexate-based chemotherapy. A mixed CC and ETT were eventually diagnosed upon consultation review. Patient #3 presented with a complete hydatidiform mole and serum hCG of 744,828 mIU/mL. Three months after methotrexate, followed by actinomycin D therapy, a uterine mass was found. Hysterectomy revealed a mixed CC and PSTT. In conclusion, the rarity, elusive presentation, and wide range of histology make the diagnosis of mixed trophoblastic tumors highly challenging. The clinical management and prognosis are dictated by each component of the tumor. CC component must be considered when the patient presents with a high serum hCG level.

Extrauterine epithelioid trophoblastic tumour and its somatic carcinoma mimics: short tandem repeat genotyping meets the diagnostic challenges

AIMS

While epithelioid trophoblastic tumour (ETT) primarily arises from the uterus, cases have been increasingly documented at extrauterine sites, originating from an ectopic gestation or presenting as a metastatic tumour, leading to the major differential diagnosis of somatic carcinoma with trophoblastic differentiation. The precise separation of a gestational trophoblastic tumour from its somatic carcinoma mimics is highly relevant and crucial for patient management and prognosis.

METHODS AND RESULTS

We summarise the clinicopathological and molecular features of four challenging epithelioid malignancies presenting at extrauterine sites, with ETT as the main differential diagnosis. All four tumours demonstrated histological and immunohistochemical features overlapping between a somatic carcinoma and an ETT, combined with inconclusive clinical and imaging findings. Serum beta-hCG elevation was documented in two cases. Short tandem repeat (STR) genotyping was performed and was informative in all cases. The presence of a unique paternal allelic pattern in the tumour tissue confirmed the diagnosis of ETT in two cases with an initial consideration of either somatic carcinoma or suspicion of a gestational trophoblastic tumour. The presence of matching genetic profile with the patient's paired normal tissue was seen in two other cases (both initially considered as ETT), confirming their somatic origin, including one metastatic triple-negative breast carcinoma and one primary lung carcinoma.

CONCLUSIONS

Diagnostic separation of ETT at an extrauterine site from its somatic carcinoma mimics can be difficult at the histological and immunohistochemical levels. STR genotyping offers a robust ancillary tool that precisely separates ETT from somatic carcinomas with trophoblastic differentiation.

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.

Genotyping diagnosis of gestational trophoblastic disease: frontiers in precision medicine

Investigations in recent decades have exploited tissue DNA genotyping as a powerful ancillary tool for the precision diagnosis and subclassification of gestational trophoblastic disease. As lesions of gestational origin, the inherited paternal genome, with or without copy number alterations, is the fundamental molecular basis for the diagnostic applications of DNA genotyping. Genotyping is now considered the gold standard in the confirmation and subtyping of sporadic hydatidiform moles. Although a precise diagnosis of partial mole requires DNA genotyping, prognostic stratification according to distinct genetic zygosity in complete moles has recently gained significant clinical relevance for patient care. Beyond hydatidiform moles, DNA genotyping has fundamental applications in the diagnosis or prognostic assessment of gestational trophoblastic tumors, in particular gestational choriocarcinoma. DNA genotyping provides a decisive tool in the separation of gestational trophoblastic neoplasia from non-gestational counterparts/mimics of either germ cell or somatic origin. The FIGO/WHO prognostic scoring scheme requires ascertaining the precise index gestational event and the time interval between the tumor and index gestation, where DNA genotyping can provide highly relevant information. With rapid acquisition of molecular diagnostic capabilities in the clinical practice, DNA genotyping has become closely integrated into the routine diagnostic workup of various forms of gestational trophoblastic disease.

LPCAT1-TERT fusions are uniquely recurrent in epithelioid trophoblastic tumors and positively regulate cell growth

Gestational trophoblastic disease (GTD) is a heterogeneous group of lesions arising from placental tissue. Epithelioid trophoblastic tumor (ETT), derived from chorionic-type trophoblast, is the rarest form of GTD with only approximately 130 cases described in the literature. Due to its morphologic mimicry of epithelioid smooth muscle tumors and carcinoma, ETT can be misdiagnosed. To date, molecular characterization of ETTs is lacking. Furthermore, ETT is difficult to treat when disease spreads beyond the uterus. Here using RNA-Seq analysis in a cohort of ETTs and other gestational trophoblastic lesions we describe the discovery of LPCAT1-TERT fusion transcripts that occur in ETTs and coincide with underlying genomic deletions. Through cell-growth assays we demonstrate that LPCAT1-TERT fusion proteins can positively modulate cell proliferation and therefore may represent future treatment targets. Furthermore, we demonstrate that TERT upregulation appears to be a characteristic of ETTs, even in the absence of LPCAT1-TERT fusions, and that it appears linked to copy number gains of chromosome 5. No evidence of TERT upregulation was identified in other trophoblastic lesions tested, including placental site trophoblastic tumors and placental site nodules, which are thought to be the benign chorionic-type trophoblast counterpart to ETT. These findings indicate that LPCAT1-TERT fusions and copy-number driven TERT activation may represent novel markers for ETT, with the potential to improve the diagnosis, treatment, and outcome for women with this rare form of GTD.

Extrauterine Epithelioid Trophoblastic Tumor Arising in the Ovary With Multiple Metastases

Epithelioid trophoblastic tumor is a neoplasm of the chorionic-type intermediate trophoblasts. It is considered a rare gestational trophoblastic disease and is frequently misdiagnosed as carcinoma. Extrauterine epithelioid trophoblastic tumor has been reported in multiple anatomical sites. We report a case of a 50-year-old woman who presented with abdominal pain and distension. Her initial β-human chorionic gonatotropin level was 806.7 IU/L. Imaging showed a large complex ovarian mass with peritoneal and subcapsular hepatic deposits as well as pulmonary nodules. Morphological features of the tumor and its immunohistochemical reactivity to CK8/18, CK7, p63, and CD10 were consistent with the diagnosis of an extrauterine epithelioid trophoblastic tumor arising from the ovary. The differential diagnoses, including other ovarian tumors, were ruled out on the basis of morphology and negative immunostaining to a relatively extended panel of antibodies. A prolonged follow up of these cases and the recognition of such rare tumors in unusual sites are crucial to the diagnosing pathologist and treating physician.

Extragestational βHCG secretion due to an isolated lung epithelioid trophoblastic tumor: microsatellite genotyping of tumoral cells confirmed their placental origin and oriented specific chemotherapy

CONTEXT

Persistent secretion of β-human chorionic gonadotropin (βHCG) in the absence of an ongoing or recent pregnancy and without persistent uterine gestational disease is a rare but challenging situation that requires locating the extrauterine secreting tumor and distinguishing between extragestational choriocarcinoma and gestational trophoblastic neoplasms.

CASE PRESENTATION

An unexplained, persistent extragestational βHCG secretion occurring in a 29-year-old, nonsmoking woman with abnormal uterine bleeding 4 years after a normal pregnancy and without persistent gestational disease led to the discovery by whole-body computed tomography/positron emission tomography of an isolated pulmonary tumor.

OBJECTIVE

Characterization of paternal alleles in tumoral cells in order to establish their fetal origin, which may be helpful for the diagnosis and treatment of such tumors.

METHODS AND RESULTS

After the surgical procedure, clinical, histological, and immunocytochemical analysis ruled out primary or metastatic bronchopulmonary carcinoma or choriocarcinoma and supported the diagnosis of an isolated, primary, epithelioid trophoblastic tumor. Microsatellite genotyping of tumoral cells identifying paternal alleles confirmed their placental origin and their migration to the lungs, with likely secondary malignant transformation, and guided the choice of postsurgical chemotherapy needed to completely eradicate βHCG secretion.

CONCLUSION

Persistent extragestational secretion of βHCG in a young nonsmoking woman with a precedent pregnancy and an isolated lung tumor suggests the diagnosis of epithelioid trophoblastic tumor, a very rare malignant tumor for which placental origin needs to be confirmed, especially when occurring several years after the patient's last pregnancy. Simple microsatellite genotyping of tumoral cells will allow this confirmation of diagnosis and help in personalizing chemotherapy.

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.

Epithelioid Trophoblastic Tumor: An Outcome-Based Literature Review of 78 Reported Cases

Objectives

Epithelioid trophoblastic tumor (ETT) is very rare; and therefore, a substantially increased data set is unlikely to be obtained in the near future. This analysis aimed to assess the effects of current management on clinical outcomes and to identify potential prognostic indicators in ETT.

Methods

We applied a literature search using PubMed to analyze the clinical data of 78 published cases of ETT.

Results

Women with ETT present at reproductive age (mean ± SD, 37.1 ± 8.7 years) and have a slightly to moderately elevated serum β-human chorionic gonadotropin (median, 665 IU/L). Epithelioid trophoblastic tumor is frequently present in the lower uterine segment/cervix (26/58 cases) and can be misdiagnosed as squamous cell carcinoma (6/26). Lung is the most common extrauterine site of ETT (5/11 with uterine ETT and 10/20 without uterine ETT). Kaplan-Meier analysis indicates that chemotherapy (surgery with postoperative chemotherapy vs surgery alone) is associated with increased ETT relapse (P= 0.005), even after stratification by International Federation of Gynecology and Obstetrics (FIGO) stage (P= 0.008); but FIGO stage remains the only significant prognostic indicator for ETT (P= 0.015).

Conclusions

This analysis confirms the hypothetical chemotherapy resistance and prognostic value of FIGO staging in ETT. These findings remain tentative given the small data set available for analysis and the reporting bias from these published cases; however, they may confer a risk-adapted therapy. Finally, both gynecologists and pathologists should be alert to the potential misdiagnosis of squamous cell carcinoma when ETT is present in the lower uterine segment/cervix.

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.

Molecular diagnosis of gestational trophoblastic disease

Gestational trophoblastic disease consists of well-defined diagnostic entities of proliferative disorder of the placenta, of which hydatidiform moles are common lesions. Even with available ancillary studies, including ploidy and immunohistochemistry analyses, histological diagnosis of molar pregnancies can be challenging in a significant percentage of the cases. Reliable diagnostic approaches with improved sensitivity and specificity are highly desirable. Recently, PCR-based short tandem repeat DNA genotyping has emerged as a powerful diagnostic measure in the workup of gestational trophoblastic disorders, particularly hydatidiform moles.