Atypical Placental Site Nodules within the Diverticulum of the Uterine Incision, a Rare Gestational Trophoblastic Disease Misdiagnosed as Intrauterine Residue: A Case Report

Atypical placental site nodule (APSN) is a rare benign gestational trophoblastic disease (GTD). It is a tumor-like transformation that has a certain probability of developing into a placental site trophoblastic tumor (PSTT) or epithelioid trophoblastic tumor (ETT). Because of its atypical clinical presentation, it is difficult to diagnose and susceptible to misdiagnosis highly, thus delaying the patient's condition. We report a scarce case of atypical nodules at the placental site of the uterine incision diverticulum in a 35-year-old female, who was irregular vaginal bleeding after a cesarean Sect. 2 years. She was diagnosed by several local hospitals with intrauterine residue and was given a variety of Traditional Chinese Medicine (TCM) orally, but the symptoms of irregular vaginal bleeding have not been alleviated. After being transferred to several hospitals, she went to Hubei Maternal and Child Health Hospital for treatment. Under the condition of excluding the second pregnancy, she underwent hysteroscopic resection of lesions and laparoscopic repair of uterine incision diverticulum. The pathological diagnosis after the operation suggested that the focus at the uterine incision was an atypical placental nodule that invaded the myometrium of the uterus. The operation completely removed the focus, and then the patient was followed up every 3 months in the first postoperative year, then every 6 months up to 3 years, and then annually thereafter up to 5 years, and then maybe every 2 years thereafter. The patient's condition was quickly controlled, and the prognosis was good.