Isolated Epithelioid Trophoblastic Tumor Mimicking Non-small Cell Lung Cancer

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.

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.

Clinical characteristics and outcomes of extrauterine epithelioid trophoblastic tumors

BACKGROUND

Epithelioid trophoblastic tumor (ETT) derived from intermediate trophoblasts is one type of gestational trophoblastic neoplasia (GTN), and it accounts for less than 2% of all gestational trophoblastic diseases (GTD). Extrauterine ETT is extremely rare, and there is currently no consistent strategy for its treatment and management. Therefore, the aim of the study is to analyze and summarize the clinicopathologic features of extrauterine ETT with or without metastasis.

METHOD

The Web of Knowledge, Google Scholar, EMbase, congress of library, and PubMed were searched for extrauterine ETT without primary uterine lesions. All available data were extracted from published case reports or serial case reports, and then, the clinical and pathological characteristics were analyzed.

RESULTS

Twenty-two clinical studies consisting of 27 patients diagnosed with extrauterine ETT, according to the given inclusion and exclusion criteria, were included in the study. A total of 27 cases of extrauterine ETT were identified. Of these cases, four (14.81%) were located in the lungs, three (11.11%) in the ovaries, two (7.41%) in the vagina, and eight (29.63%) patients had other primary lesions. The patients originated from different continents, with 59% located in Asia and 26% in North America. Among 23 patients, the antecedent pregnancy prior to the diagnosis was full-term in 12 cases, abortion in 6 cases, hydatidiform mole in 3 cases, and invasive mole in 1 case. From the available antecedent information on pregnancy, the median interval from pregnancy to diagnosis of extrauterine ETT was 4 years. Additionally, the median gravidity and para of the patients was three times and two times, respectively. The median hCG titer was 14,374 mIU/mL in 5 patients, and the mean β-HCG titer was 3,724,805 mIU/mL in 14 patients. For all patients, the disease was confined to extrauterine ETT at diagnosis. From the available information, 20 cases were successfully treated by extraction of local lesions, and 12 cases received chemotherapy. Diagnosis was confirmed by histological tests. The Ki-67 staining ranged from 8.7 to 80%, and tumors were positive for hCG, PLAP, EMA, and p63.

CONCLUSION

In this study, we observed that abnormal levels of serum hCG titers and the local presentation of lesions with varying intervals after antecedent term pregnancy were the most common presenting features of extrauterine ETT. In addition, we found that the extraction of extrauterine lesions was needed for the treatment of extrauterine ETT. Of course, the follow-up was also important.

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.

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.