[Clinical characteristics and diagnosis of early hydatidiform mole]

Objective: To evaluate the clinical characteristics and diagnostic strategies of early hydatidiform mole. Methods: A retrospective cohort study was conducted of 526 women with hydatidiform mole who underwent suction curettage and were confirmed by histopathology in Dalian Maternal and ChildHealth Care Hospital from Feb. 2013 to Feb. 2018, including 484 women with gestational age less than or equal to 12 weeks (the early group) and 42 women with gestational age greater than 12 weeks (the late group). The clinical characteristics between the two groups were compared, and the pathological diagnosis and pre-evacuation ultrasound examination of the early group were further discussed. Results: Compared with the late group, the clinical characteristics of the early group tended to be atypical, and the incidence of vaginal bleeding, excessive uterine size, theca lutein cysts (>6 cm) and pregnancy complications decreased significantly (all P<0.05). The serum level of β-hCG in the early group was significantly lower than that in the late group (Z=-2.382, P=0.017). While there was no significant difference in the pre-evacuation ultrasound detection rate between the two groups (53.5% vs 66.7%; χ(2)=2.697, P=0.101). Five hundred and fifteen patients completed the follow-up, and 38 patients with post-mole neoplasia were all cured. There was no significant difference in the malignant transformation rate of hydatidiform mole between the two groups (7.0% vs 11.9%; χ(2)=0.745, P=0.388). In the early group, 302 cases of complete hydatidiform mole (CHM), 179 cases of partial hydatidiform mole (PHM) and 3 cases of unclassified hydatidiform mole (UHM) were histologically diagnosed, according to pathological morphology combined with p57(KIP2) immunohistochemical staining. Compared with pathological diagnosis, the overall pre-evacuation ultrasound detection rate in the early hydatidiform mole was 53.5% (259/484), which was significantly better for complete (78.1%, 236/302) versus partial (11.7%, 21/179) hydatidiform moles (χ(2)=199.224, P<0.01). There was significantly weak negative correlation between the overall ultrasound detection rate and gestational age of hydatidiform mole (r=-0.211, P<0.01). The gestational age of early PHM was significantly longer than that of CHM (68.0 vs 58.5 days; Z=-8.048, P<0.01). Conclusions: The clinical presentations of early hydatidiform mole are not typical. Although ultrasound examination identifies only about half of hydatidiform moles, ultrasonography is still an important auxiliary examination method. Morphological examination combined with p57(K)IP2 immunohistochemical staining could effectively diagnose early hydatidiform mole, so as to reduce the missed diagnosis of hydatidiform mole.