BackgroundGestational trophoblastic neoplasia is an uncommon disease, whose clinical manifestations are similar to ectopic pregnancy, thus some rare pelvic lesion can be misdiagnosed as ectopic pregnancy.AimsThis study was presented to investigate the characteristics of gestational trophoblastic neoplasia misdiagnosed as ectopic pregnancy and reduce the misdiagnosis.MethodsThe clinicopathological data for 14 cases of gestational trophoblastic neoplasia misdiagnosed as ectopic pregnancy at West China Second Hospital Sichuan University from January 2006 to December 2020 were retrospectively analyzed.ResultsThe main clinical manifestations were amenorrhea, abnormal vaginal bleeding, and abdominal pain. At initial diagnosis, the serum hCG level was >10,000 mIU/mL in 5 patients and <10,000 mIU/mL in 7 patients, and a positive urine pregnancy test alone was found in 2 patients. Vaginal ultrasonography showed no abnormalities in 7 cases, adnexal mass in 5 cases, and tubal thickening in 2 cases. The patient's previous pregnancy was an abortion in 7 cases, full-term in 4 cases, and a hydatidiform mole in 3 cases. Clinical stage: 3 cases were stage I, 3 were stage II, 7 were stage III, and 1 case was stage IV (liver and spleen metastases). The median FIGO prognostic score was 13.5 points (12–21 points), with 9 cases having a score >13 points (very high risk). From 14 patients, only 3 had molar pregnancy previously. Only 3 patients had no metastasis at GTN diagnosis (from these 3, only one after molar pregnancy). After chemotherapy alone or in combination with surgery, all patients survived, with a median follow-up of 84 months (23–102 months).ConclusionIf we have positive hCG, without a sonographic topic gestation confirmation, associated with metastatic lesions, the GTN diagnosis should be considered instead of ectopic pregnancy, if the patient have had a pregnancy once during her life.