OBJECTIVE: Placental site trophoblastic tumor (PSTT) is a rare form of gestational trophoblastic neoplasm with few previous imaging case reports. We report multiparametric MRI findings in four cases of PSTT with special emphasis on the \"pseudo-myometrial thinning\" underlying the tumor.
METHODS: We reviewed multiparametric MRI and pathologic findings in four cases of PSTT from four institutions. Signal intensity, enhancement pattern, margins, and location of the tumors were evaluated, and myometrial thickness underlying the tumor and normal myometrial thickness contralateral to the tumor were measured on MRI. The myometrial thickness underlying the tumor was also measured in the resected specimen and compared with the myometrial thickness measured on MRI using the Friedman test.
RESULTS: All tumors showed heterogeneous signal intensity on T1-weighted imaging, T2-weighted imaging (T2WI), and diffusion-weighted imaging. Three of the four tumors had a hypervascular area on dynamic contrast-enhanced (DCE) MRI. A hypointense rim on T2WI and DCE-MRI was seen in all tumors. All tumors protruded into the uterine cavity to varying degrees and extended into the myometrium close to the serosa. The myometrial thickness underlying the tumor measured on MRI (median thickness, 1.2 mm) was significantly thinner than that measured on pathology (median thickness, 9.5 mm) and normal myometrial thickness contralateral to the tumor on MRI (median thickness, 10.3 mm) (P = 0.02), and there was no significant difference between the latter two.
CONCLUSIONS: The thickness of the myometrium underlying the tumor on MRI was approximately one tenth of the thickness on pathology. Thus, the tumors appeared to have almost transmural invasion even when pathologically located within the superficial myometrium. This \"pseudo-thinning\" of the underlying myometrium and the hypointense rim on MRI could be caused by focal compression of the myometrium by the tumor, possibly due to the fragility of the myometrium at the placental site.

Placental trophoblastic site tumor (PSTT) is a rare type of gestational trophoblastic neoplasia (GTN). PSTT has a higher mortality than other types of gestational trophoblastic disease (GTD), with a rate of 16.1%, due to its relatively unpredictable behavior and reduced response to chemotherapy. Its diagnostic and management are very challenging in Low resources settings particularity in Haiti where MRI, PET Scan and IHC are not available. Further, the follow-up is very difficult because of social, political, and economic issues limiting the capacity of our patients to be present at all scheduled visits. No case of PSTT has been publicly described yet the Haitian experience in the literature in the management of such case compared to the developed world. We present a case of PSTT successfully diagnosed and managed at Mirebalais University Hospital (MUH) in Haiti with the support of telepathology and intentional partners while highlighting the difference that we observed compare to the developed world.

Placental site trophoblastic tumor (PSTT), also known as atypical choriocarcinoma, syncytioma, chorioepitheliosis or trophoblastic pseudotumor, is a rare gestational trophoblastic disease (0.25-5% of all trophoblastic tumors) and it is composed by neoplastic proliferation of intermediate trophoblasts at placental implantation site. It consists of aggregates or sheets of large, polyhedral to round, predominantly mononucleated cells with a characteristic vascular and myometrial invasion. Main differential diagnoses are gestational choriocarcinoma (GC) and epitelioid trophoblastic tumor (ETT). We present a case of PSTT in a 25-year-old woman. Neoplastic cells showed moderate/high nuclear pleomorphism, abundant amphophilic, eosinophilic and clear cytoplasm, numerous mitotic figures (10 mitoses/10 HPF), and myometrial invasion. Other features are necrosis, vascular invasion with replacement of myometrial vessels by tumor cells and hemorrhage. The patient showed typical low serum β-hCG levels and high serum humane placental lactogen (hPL) levels.

BACKGROUND: Gestational trophoblastic disease (GTD) constitutes a spectrum of tumors and tumor-like conditions, characterized by proliferation of pregnancy-associated trophoblastic tissue of progressive malignant potential. It is very difficult to differentiate these complex groups of lesions basing on histomorphology alone. Immunohistochemistry (IHC) with cyclin E, P63, and Ki-67 has a definite role in the identification of different trophoblasts and entities of GTD and also in the determination of biological behavior.
OBJECTIVE: The aim of this study is to find the differential expression of cyclin E, p63, and Ki-67 in normal placenta, hydropic abortus (HA), and various entities of GTD.
METHODS: A prospective case-control study conducted in a government medical college.
METHODS: Total 96 cases, divided into Group A (48 histologically confirmed cases of GTD) and Group B (controls comprising 8 HA and 40 normal placentas of different trimesters), were studied. The histological samples were subjected to IHC using cyclin E, Ki-67, and p63.
METHODS: Results were analyzed using SPSS statistical method.
RESULTS: Among the three immunomarkers used, Cyclin E and Ki-67 show statistically significant difference (P < 0.05) when compared between GTD and control groups, but it was insignificant for p63 (P = 0.369). Strong staining intensity of cyclin E and Ki-67 is seen in complete moles, choriocarcinoma, and placental site trophoblastic tumor.
CONCLUSIONS: This study was done to evaluate the role of cell cycle regulatory proteins such as cyclin E and p63 and proliferation marker Ki-67 in the detection of various trophoblasts and differential diagnosis of the lesions associated with them.

Placental site trophoblastic tumor (PSTT) is the rarest subtype of gestational trophoblastic neoplasm. We present a case of PSTT complicating nephrotic syndrome. A 32-year-old woman experienced irregular menstrual bleeding and lower extremity edema 18 months after delivery. She was diagnosed with nephrotic syndrome and exaggerated placental site based on the hysteroscopic biopsy results. During follow-up, transvaginal color Doppler ultrasound showed an enlarged uterus filled with a hypervascular mass. Positron emission tomography-computed tomography showed diffuse accumulation in the entire uterus. The patient was diagnosed with PSTT only after total hysterectomy. Postoperatively, serum β-human chorionic gonadotropin decreased to within the normal range and her nephrotic syndrome resolved. She has remained without evidence of recurrence for 15 months. It is difficult to diagnose PSTT definitively. Most patients with PSTT are of reproductive age, therefore, to maintain fecundity, therapy development is expected.

Placental site trophoblastic tumor (PSTT) is a rare form of gestational trophoblastic neoplasia (GTN). It most commonly occurs after a delivery but may arise after any type of pregnancy. PSTT arises after neoplastic transformation of intermediate trophoblastic cells. The most commonly reported symptoms are abnormal bleeding or amenorrhea. Due to the rarity of this disease, evidence on prognostic factors as well as optimal treatment is limited. While treatment for early-stage disease is usually limited to surgery, multimodal treatment with chemotherapy and surgery may be important for metastatic disease. Metastatic disease may be associated with minimal elevations of human chorionic gonadotropin (hCG). Here we present an unusual case of a patient with PSTT and an isolated breast metastasis who was successfully treated with surgical resection and single-agent chemotherapy.

OBJECTIVE: Placental site trophoblastic tumor (PSTT) is rare and is characterized by a slow growth. The objective of this report is to present a case of PSTT associated with irregular vaginal spotting that occurred 1 year after normal vaginal delivery.
METHODS: This report provides interesting ultrasound, hysteroscopy, and histology findings of PSTT. It is difficult to make a clinical diagnosis of PSTT at an early stage. Without the use of immunohistochemical analysis, PSTT may evade histological detection. An operative hysteroscopy using electrocauterization reduces active bleeding during the removal of PSTT with markedly engorged tumor vessels.
CONCLUSIONS: Transvaginal sonography using color Doppler imaging plays a vital role in identifying residual PSTT with microscopic infiltration to the myometrium and a negative serum β-human chorionic gonadotropin level.

Placental site trophoblastic tumor (PSTT) is a very rare variant of gestational trophoblastic tumor. It can occur after normal termination of pregnancy or spontaneous abortion and ectopic or molar pregnancy. There is a wide range of clinical manifestations from a benign condition to an aggressive disease with fatal outcome. One of the most important characteristics of PSTT, unlike other forms of gestational trophoblastic diseases (GTD) is the presence of low beta-subunit of human chorionic gonadotropin (β-hCG) levels because it is a neoplastic proliferation of intermediate trophoblastic cells. However, human placental lactogen (hPL) is increased on histologic section and in the serum of patients too. We present a case of PSTT and discuss the differential diagnosis in order to further familiarize physicians with the diagnosis and treatment of this disease. It has a varied clinical spectrum and usually presents with irregular vaginal bleeding or amenorrhea. Diagnosis is confirmed by dilatation and curettage (D and C) and hysterectomy. Because chemotherapy is not effective, surgery is the cornerstone of treatment. This case is presented because it is a rare neoplasm with different treatments and it should be differentiated from molar pregnancy.

We present a case of a gravida 1 para 1 woman, who presented with an 11-month history of amenorrhea after cesarean delivery. The patient was taking birth control pills at the time of presentation. She was observed with a slight elevation of serum β-hCG level, an enlarged heterogeneous uterus and hematometra. A biopsy was performed, and the patient was diagnosed with placental site trophoblastic tumor; the patient then underwent surgery. Placental site trophoblastic tumor is the rarest form of gestational trophoblastic disease, derived from intermediate trophoblast cells. It does not have a pathognomonic appearance; therefore, correlation with medical history, as well as results of laboratory tests and pathological analysis is mandatory. It is a relatively chemoresistant tumor, posing considerable therapeutic challenges; patients with localized disease are managed with surgery and those with metastatic disease require additional chemotherapy. Herein, we review the main features of this entity and top differential diagnosis, as the rarity of this tumor is associated with imaging and pathological pitfalls, reinforcing the need for further experience in this field.

Gestational trophoblastic neoplasms are a group of fetal trophoblastic tumors including choriocarcinomas, epithelioid trophoblastic tumors (ETTs), and placental site trophoblastic tumors (PSTTs). Mixed gestational trophoblastic neoplasms are extremely rare. The existence of mixed gestational trophoblastic neoplasms that were composed of choriocarcinoma and/or PSTT and/or ETT was also reported. Herein, we present a case of uterine mixed gestational trophoblastic neoplasm which is ETT admixed with PSTT, and reviewed 9 cases of mixed gestational trophoblastic neoplasms reported in English literature available. The most common combination was a choriocarcinoma admixed with an ETT and/or PSTT. Mixed gestational trophoblastic neoplasms present in women of reproductive age and rare in postmenopausal, Abnormal vaginal bleeding is the most common presenting symptom, serum β-HCG levels are elevated, mostly below 2500 mIU/ml, the tumor was limited to uterus in 7 cases, the rest of 3 with pulmonary metastases at the time of diagnosis. Mixed gestational trophoblastic neoplasms have more similar clinical features with intermediate trophoblastic tumors (ITTs). Total hysterectomy with lymph node dissection is recommended treatment for mixed gestational trophoblastic neoplasms, and chemotherapy should be used in patients with metastatic disease and with nonmetastatic disease who have adverse prognostic factors.