Tumors of trophoblast implantation site TTSI are rare gestational tumors. This case highlights the diagnostic difficulties and treatment of tumors of trophoblastic implantation site early. Patient of 28 years with no medical history, G1P1 who gave birth 11 months ago presented bleeding with an HCG level of 73IU that led to the diagnosis of early miscarriage. Treatment of miscarriage by hysteroscopy and curettage is complicated leading to the realization of an abdominopelvic CT and pelvic ultrasound that show an atypical uterine vascularity and an intracavitary heterogeneous mass. The pelvic MRI performed evokes a TTSI stage I. A hysterectomy with bilateral salpingectomy and ovarian conservation is achieved. Despite the standard treatment with surgery the HCG levels do not normalize before seven months after surgery. This indicates an adjuvant chemotherapy, the patient refuses. The presented case illustrates the diagnostic difficulties of the disease. He noted the importance of the second reading network proposed by the specialized center in Lyon. It also raises the question of adjuvant chemotherapy in some cases of early stage TTSI. The challenge is to define cases requiring adjuvant therapy. Predictors of chemotherapy in early stages could be tumor size, degree of infiltration of the myometrium and mutation p53. Amenorrhea, bleeding associated with uterine atypical vascularization, and atypical development of HCG<1000IU and/or unusual complications of treatment of miscarriage should evoke a tumor site trophoblastic implantation. Hysterectomy is the first treatment in early stages. Tumor size, degree of infiltration of the myometrium and mutation p53 are predictors to assess in multicentre studies to define the indications of postoperative chemotherapy.