Management of placental site trophoblastic tumor. Two case reports

Rationale: Placental site trophoblastic tumor (PSTT) is a very rare malignant tumor, belonging to a family of pregnancy-related illnesses, called gestational trophoblastic diseases (GTD). Less than 300 cases of PSTT have been reported in literature, with an incidence of≈1/50,000–100,000 pregnancies representing only 0.23% to 3.00% of all GTDs. Patient concerns: Our report describes 2 additional cases of PSTT outlining their main diagnostic features and the subsequent management. The first case presented contemporary to a persistent hydatidiform mole in a 37-year-old woman, para 2042; whereas the second one originated 5 years after a miscarriage in 43-year-old woman, para 1031 with a previous diagnosis of breast cancer, and shared some features with placental site nodule (PSN), a benign condition. Diagnosis: The first case had a difficult diagnosis because there was an amenorrhea of 11th week with high serum beta-human chorionic gonadotropin (beta-HCG) and an initial ultrasound image of vesicular mole. After the Dilatation and Curettage, histology confirmed the previous hypothesis. However, the final histology of PSTT was obtained after major surgery. On the contrary, the diagnosis of the second case was less challenging but surprising, thanks to a routine trans-vaginal ultrasound showing a suspiciousendometrial thickness positive for PSTT at a subsequent hysteroscopic guided biopsy.Interventions:The treatment consisted of hysterectomy and subsequent follow up. Lymphadenectomy or lymph node sampling were not performed due to the initial stage of the disease. Outcomes: In the first case, there were high values of serum beta-HCG that plummeted after the surgery, whereas in the second one they had been always negative. Hereafter, both went through a follow up with periodic serum oncological markers, imaging studies and clinical evaluation, which have showed negative result for 3 years and 15 months, respectively. Lessons: A detailed gynecological ultrasound examination could be extremely helpful to understand the next diagnostic step of echo-guided D&C or hysteroscopic biopsy and for a pre-operative staging assessment. On the contrary, determining the serum beta-HCG’s curve is crucial just in case of an initial positive value to pursue clinical evaluation and follow-up. In case of good prognostic factors, the main therapy remains hysterectomy.