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

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.

Ovarian non-gestational placental site trophoblastic tumor with lung metastasis: further evidence for a distinct category of trophoblastic neoplasm

We previously described a series of cases which characterize a distinct group of primary ovarian placental site trophoblastic tumor (PSTT) and epithelioid trophoblastic tumor (ETT) as a non-gestational set consistent with germ cell type/origin. Here we report a new case of ovarian non-gestational PSTT. The patient was a 13 year-old young female admitted for a spontaneous pneumothorax of the left lung. The pathology of lung wedge excision specimen demonstrated metastatic PSTT and ovarian biopsy showed atypical intermediate trophoblastic proliferation which was found to be PSTT in the subsequent salpingo-oophorectomy specimen. In the ovary, the tumor was composed of singly dispersed or small clusters of predominantly mononuclear cells and rare multinucleated cells extensively infiltrating the ovarian parenchyma, tubal mucosa, and paraovarian/paratubal soft tissue. A minor component of mature cystic teratoma (less than 5% of total tumor volume) was present. Immunohistochemically, the neoplastic cells of main tumor were diffusely immunoreactive for hPL, Gata3 and AE1/AE3, and had only rare hCG-positive or p63-positive cells. The morphology and immunohistochemical results support a PSTT. Molecular genotyping revealed an identical genotype pattern between the normal lung tissue and the metastatic PSTT, indicating its non-gestational nature of germ cell type/origin. This case represents the first case of such tumor with distant (lung) metastasis. This case also provides further evidence to support our recommendation that primary ovarian non-gestational intermediate trophoblastic tumors of germ cell type/origin, including PSTT and ETT, should be formally recognized in classification systems.