Rationale: The incidence of a unicornuate uterus is 0.2% to 0.3% of the whole population. A unicornuate uterus is closely associated with obstetrical complications such as early miscarriages, ectopic pregnancy, and malpresentation. Patient concerns: A 32-year-old patient developed a rare ectopic pregnancy arising at a distal, fimbriated end of the undescended fallopian tube. Diagnoses: A transvaginal ultrasound scan revealed hemoperitoneum and no gestational sac in the uterine endometrium. A laparoscopic finding showed that high up in the right abdomen, just below the liver, an ectopic mass could be seen arising at a distal, fimbriated end of the fallopian tube, which was developed adjacent to the undescended right ectopic ovary. Interventions: After laparoscopic removal of the right salpinx, we removed it with a bag. Outcomes: One day after the operation, she was discharged without problems. Postoperative hysterosalpingography showed the unicornuate uterus with patent left and some right salpinx. Magnetic resonance imaging revealed a unicornuate uterus, right ovary at the right inferior hepatic area, a bilateral normal kidney, and double inferior vena cava. Lessons: This is the first reported case of its type. It demonstrated that ectopic pregnancy may occur in the upper abdomen, not in the pelvic cavity, in uterine anomaly, and double inferior vena cava; hence, we must thoroughly check the whole abdominal cavity. Additional imaging tests are needed after treatment to see if there are any abnormalities.

Knowledge of common and characteristic MDCT findings of AT according to the anatomical subtypes is important to make accurate diagnosis and avoid delayed treatment.