A positive urine pregnancy test with haemoperitoneum: misdiagnosed postpartum choriocarcinoma with uterine rupture mimicking ruptured ectopic pregnancy

Objectives: Choriocarcinoma after a term pregnancy is rare and can be life-threatening, especially when it perforates the uterus, resulting in massive haemoperitoneum. As uterine rupture due to choriocarcinoma is uncommonly encountered in the clinical practice, its diagnosis is often missed or delayed. Case presentation: We present a case of a 41-year-old para 4 + 1 who had acute abdomen and hypovolaemic shock secondary to haemoperitoneum at three months postpartum period. The urine pregnancy test was positive, and, therefore, a provisional diagnosis of a ruptured ectopic pregnancy was made. She was managed aggressively with fluids and blood product transfusion at the emergency department to achieve haemodynamic stability. Subsequently, she underwent an emergency laparotomy where intraoperatively noted a perforation at the left posterior uterine cornu with purplish tissue spillage. A wedge resection was performed, and the histopathological examination (HPE) was reported as atypical trophoblastic cells, in which choriocarcinoma could not be ruled out. The patient then underwent a total abdominal hysterectomy three weeks later. The final HPE confirmed the diagnosis of choriocarcinoma. Conclusions: The clinical presentation of postpartum choriocarcinoma can be indistinguishable from a ruptured ectopic pregnancy. A high index of suspicion is crucial to allow early diagnosis.