Invasive Hydatidiform Mole Mimicking Ectopic Pregnancy: A Case Report and Literature Analysis

Abstract

BACKGROUND Gestational trophoblastic diseases (GTDs) are a group of benign and malignant tumors that arise from placental tissue. Ectopic pregnancies most commonly occur within the fallopian tubes. The estimated incidence of ectopic gestational trophoblastic diseases (GTDs) is approximated at 1.5 per 1 000 000 pregnancies, which makes it a very rare condition. The diagnosis is challenging since the clinical presentation often mimics conventional ectopic pregnancy, but management approaches are significantly different. CASE REPORT A 41-year-old woman (G7 T4 P0 A2 L4) presented to the Emergency Department with a period of amenorrhea followed by vaginal bleeding and abdominal pain. Right-side abdominal tenderness was noted upon physical examination. Laboratory investigations showed elevated serum ß-hCG level. Ultrasound examination showed a normal-size uterus. No intrauterine gestational sac was identified. An echogenic mass with central lucency was noted in the right adnexa, measuring 2.1×1.8 cm, with minimal free fluid present in the pouch of Douglas. The findings were suggestive of a ruptured right-side ectopic pregnancy. The patient underwent laparoscopic salpingectomy. Histopathological examination of the specimen revealed a complete hydatidiform mole with vascular invasion. The patient was treated conservatively and was followed up by a serial ß-hCG level until she achieved 3 consecutive negative ß-hCG titers. CONCLUSIONS Invasive moles located in the fallopian tube are very rare in the literature, and further research is needed to ascertain the proper management of such cases. Histopathological examination of the salpingectomy specimen has an essential role in confirming the diagnosis of ectopic GTDs and guiding the management.

Figure 1.

A photomicrograph showing an abnormal avascular chorionic villous with diffuse cytotrophoblastic and syncytiotrophoblastic proliferation. Part of the fallopian tube is shown in the right lower corner (star) (hematoxylin and eosin, ×100 magnification).

Figure 2.

A photomicrograph depicting vascular invasion by sheets of proliferating cytotrophoblasts and syncytiotrophoblasts (hematoxylin and eosin, ×100 magnification).

Figure 3.

CD31 immunohistochemical stain highlighting the endothelial cells in an invaded blood vessel (CD31 immunohistochemical stain, ×100 magnification).

Figure 4.

A timeline showing the clinical presentation from the time of presentation until the last follow-up.