An unexpected invasive hydatidiform mole in a rudimentary uterine horn: A case report

Rudimentary horns of the uterus develop as a result of a partial non-development of one Müllerian duct, a type of congenital uterine anomaly. Pregnancy in a rudimentary horn is uncommon and the outcome tends to be poor, with the majority of cases resulting in rupture between 10 and 15 gestational weeks, with significant risk of morbidity and mortality. Regardless of the availability of imagiological procedures and the advances being made in this field, the diagnosis of this type of ectopic pregnancy often only occurs during laparotomy or laparoscopy subsequent to abdominal pain and collapse. The present study describes a rare case of a uterine rudimentary horn pregnancy. The case was diagnosed by the high serum β-HCG level, imageological results and dissection of the final pathological specimen, by combined hysteroscopy and laparoscopy. An ultrasound illustrated a suspicious gestational trophoblastic disease in the rudimentary uterine horn, with a rich blood flow signal at the right side of the uterus. A pelvic magnetic resonance image indicated that there was endometrial thickening and gestational trophoblastic disease in the rudimentary uterine horn. The patient was treated with surgery, including rudimentary horn dissection and diagnostic curettage; the ipsilateral adnexa was conserved as it appeared to be normal. Due to the apparent decline of the serum β-HCG level and the reluctance for chemotherapy, the patient chose to undergo no further treatment and closed follow-up. At the time of writing, the patient is in a good condition. Only a small number of reports of a horn pregnancy with invasive hydatidiform mole are described by other studies, thereby increasing the clinical significance of this case.