GTN misdiagnosed as ectopic pregnancy: a 17-year retrospective cohort study

To evaluate the effect of misdiagnosis on the chemotherapy response and prognosis of gestational trophoblastic neoplasia (GTN), and to explore strategies to enhance precision management of uncertain GTN.

GTN patients misdiagnosed as ectopic pregnancies were retrospectively enrolled. GTN without misdiagnosis were randomly selected as control group at a 1:1 ratio, matching by age, WHO risk score and admission year. All patients were followed up for pregnancy, recurrence, and survival. Mann-Whitney test was used for continuous variables. Categorical variables were assessed using the Chi-square test or Fisher's exact test.

Among 35 misdiagnosed cases, high-risk GTN accounted for 57.1 %. Antecedent nonmolar pregnancy in misdiagnosed group was 88.6 %. Pretreatment human chorionic gonadotropin (hCG) was lower (3477 vs 18,121 IU/L) while recurrence rate was significantly higher in misdiagnosed group than in control group (28.6 % vs 5.7 %, p = 0.011). The resistance rate showed an increasing trend in misdiagnosed group (22.9 % vs 14.3 %, p = 0.356). For subgroup analysis, the resistance rate was increased in group A (treated with methotrexate) than group B (without methotrexate), while decreased in patients with lesion resection (group C) than without resection (group D), especially for low-risk patients. Histopathological misdiagnosis for antecedent pregnancy and GTN in primary hospitals were 2 and 6 cases respectively.

GTN after nonmolar pregnancy with low hCG are prone to be misdiagnosed, which might lead to increased WHO risk scores, resistance, and relapse rates. Surgical intervention, especially lesion resection instead of methotrexate, is recommended for atypical GTN.