Atif Zeadna2 and Togas Tulandi1
McGill University Health Center, 687 Pine Ave West, H3A 1A1 Montreal, QC, Canada
Soroka University Medical Center, Beersheba, Israel
Togas Tulandi (Corresponding author)
Molar ectopic pregnancyMolar pregnancyEctopic pregnancy
A 33-year-old South Asian woman presented to the emergency department with left-sided low abdominal pain and a positive pregnancy test. Her last menstrual period was 6 weeks prior to this presentation. Past history revealed a right salpingectomy for tubal ectopic pregnancy a year before. Physical examination revealed a stable patient with mildly tender abdomen.
The serum human chorionic gonadotropin (hCG) level was 18,500 IU/L. Transvaginal ultrasound examination revealed absence of intrauterine pregnancy and a 2-cm adnexal mass in the left adnexa with hydropic changes similar to molar pregnancy.
Diagnosis and Assessment
Ectopic molar pregnancy is a rare entity and the majority of cases are located in the fallopian tube. It has been reported in the uterine cornua and in the ovaries as well . Heterotopic molar pregnancy can also occur. Histopathologically, it could be incomplete mole (35 %), hydropic degeneration of the villi (26 %), complete mole (19 %), or choriocarcinoma (13 %) [1–3].
The incidence of molar pregnancy in general varies according to the region. In the USA, Europe, and Australia, it is 0.57–1.1 per 1000 pregnancies but in Southeast Asia and Japan around 2 per 1000 pregnancies. Ectopic molar pregnancy is very rare with an estimated incidence of 0.00005 % in USA and 0.01 % in Southeast Asia. Invasive molar disease in the fallopian tube is very rare and there have been only four cases reported in the literature [1, 4–6].
Risk factors of molar pregnancy include previous molar pregnancy, Asian or Hispanic ethnicity, recurrent miscarriage, maternal age of less than 20 or more than 40 years, blood type A or AB, dietary deficits, NLRP7 gene mutations on chromosome 19q, or pregnancy after ovulation induction [1, 7–9].
The sign and symptoms of women with ectopic molar pregnancy are similar to those with tubal ectopic pregnancy. They include amenorrhea, abdominal pain, vaginal bleeding, empty uterus, abdominal mass, hyperemesis, elevated level of serum hCG, or tubal rupture .
Molar ectopic pregnancy can be diagnosed by pelvic ultrasound, Doppler studies, and elevated level of hCG . Magnetic resonance imaging (MRI) can be helpful for localization of the ectopic pregnancy. Yet, it is difficult to distinguish molar tubal pregnancy from the usual tubal ectopic pregnancy. The diagnosis is usually established at surgery and by histopathological examination.
Patients with ectopic molar pregnancy should be evaluated for anemia, hyperthyroidism, and toxemia. Physical examination and laboratory test for liver and renal function tests, complete blood count (CBC), and blood type should be done before treatment. Compared to the usual tubal pregnancy, tubal molar pregnancy has a higher tendency of rupture. Laparoscopic salpingectomy is needed. Most patients will achieve full remission quickly after surgical management without chemotherapy . The efficacy and safety of medical management ectopic molar pregnancy is unclear. More importantly, tissue pathology is needed to rule out the presence of malignancy (Fig. 19.1).
Massive peritubal hemorrhage and large elongated chorionic villi displaying hyperplastic trophoblast (a), and cysterns with trophoblastic proliferation (b). Stroma exhibits prominent karyorrhexis (c). Immunohistochemically, p57kip2 nuclear stain was not expressed in the cytotrophoblast and stromal cells, but was prominent in the extravillous (intermediate) trophoblasts (d). (Reprinted from International Journal of Surgical Pathology  with permission)
Due to the presence of ectopic pregnancy in the fallopian tube, the patient underwent laparoscopic salpingectomy. Histopathological examination revealed a molar tubal pregnancy. Chest X ray was reported to be normal. The serum hCG level a week after surgery was 5000 mIU/mL, and a week later was 2100 mIU/mL. The levels continued dropping and 4 weeks after surgery, it was undetectable.
· Ectopic molar pregnancy is rare.
· Invasive mole and choriocarcinoma are rare complications.
· Clinical diagnosis is difficult.
· Approach and follow-up with tertiary center is important since inadequate treatment of molar pregnancy can lead to choriocarcinoma.
· Surgical removal of the affected tube is mandatory.
· Histopathological examination is needed to rule out the presence of malignancy.
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