Retrospective analysis of the clinicopathologic and prognostic characteristics of stage I placental site trophoblastic tumor in China

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

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

Clinical characteristics and outcomes of placental site trophoblastic tumor: experience of single institution in Korea

Objective

Placental site trophoblastic tumor (PSTT) is the rarest form of gestational trophoblastic disease (GTD) and the optimum management is still controversial. In this study, we analyzed the clinical features, treatment, and outcomes of 6 consecutive patients with PSTT treated in our institution.

Methods

The electronic medical record database of Samsung Medical Center was screened to identify patients with PSTT from 1994 to 2017. Medical records for the details of each patient's clinical features and treatment were extracted and reviewed. This study was approved Institutional Review Board of our hospital.

Results

A total of 418 cases of GTD, 6 (1.4%) patients with PSTT were identified. The median age of the patients was 31 years. The antecedent pregnancy was term in all 5 cases with available antecedent pregnancy information and the median interval from pregnancy to diagnosis of PSTT was 8 months. The median titer of serum beta human chorionic gonadotropin (β-hCG) at diagnosis was 190.9 mIU/mL. Five (83.3%) patients presented with irregular vaginal bleeding and one (16.7%) had amenorrhea. All patients had disease confined to the uterus without metastasis at diagnosis and were successfully treated by hysterectomy alone. All of them were alive without disease during the follow-up period.

Conclusion

In this study, we observed low level serum β-hCG titer and irregular vaginal bleeding with varying interval after antecedent term pregnancy were most common presenting features of PSTT. In addition, we demonstrated hysterectomy alone was successful for the treatment of stage I disease of PSTT.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Placental site trophoblastic tumor: A case report and literature review

Here, we report a case of a placental site trophoblastic tumor (PSTT) in a 36-year-old Chinese woman 10 months after a normal pregnancy. Two months postpartum, the woman presented with abnormal vaginal discharge and her condition was overlooked by her local hospital. The woman did not receive further attention until a mass with a heterogeneous echo was found in an ultrasound examination eight months postpartum. The final diagnosis was confirmed by histological examinations in conjunction with immunohistochemical studies. Since the patient had potential risk factors, she was successfully treated with a hysterectomy and peri- and post-operative chemotherapy. The latest follow-up (16 months after diagnosis) was uneventful, and the patient exhibited no signs of recurrence or metastasis.