Live ectopic pregnancy

Clinical History

Abdominal pain of 24 hours duration in a 35 year old woman.

Imaging Findings

A 35 year old woman presented with upper abdominal pain of 24 hours duration. There was no significant past medical history apart from oligomennorrhoea. Physical examination was unremarkable. She was referred for diagnostic abdominal ultrasound. Ultrasound revealed free fluid throughout the abdominal cavity. The upper abdominal organs were unremarkable. The uterus was empty but a cystic structure was noted in the left adnexa. Closer inspection revealed it to be a gestation sac containing an embryo with a detectable heartbeat. The presence of a gestation sac outside the uterus was proof of an ectopic pregnancy. The woman underwent immediate laparotomy and a left tubal ectopic with hemoperitoneum was confirmed.

Discussion

1.4% of pregnancies are ectopic. 95% of ectopic pregnancies occur in the fallopian tube but rarer sites include ovary, cervix and peritoneum. The risk of ectopic pregnancy is greater if there is an underlying fallopian tubal abnormality, a history of prior tubal surgery or of pelvic inflammatory disease, or if an intrauterine contraceptive device is in situ. Women being treated for infertility are at particular risk. The typical clinical presentation is with vaginal bleeding and pain in the first trimester of pregnancy. The role of ultrasound in this clinical setting is to determine if an intrauterine pregnancy is present. The presence of an intrauterine pregnancy virtually excludes the diagnosis of ectopic pregnancy. Only rarely ( 1 in 7000) does an intrauterine pregnancy and an ectopic pregnancy co-exist. Examination should include transvaginal as well as transabdominal ultrasound. Correlation with serum beta-hcg levels is essential. If the beta-hcg level is greater than 1800 mIU/ml (second international standard) it should always be possible to identify an intrauterine gestational sac using transabdominal ultrasound. Using transvaginal ultrasound, an intrauterine sac should be visible at beta-hcg levels of greater than 1000 mIU/ml. The visualisation of a live embryo in the adnexa is specific evidence of an ectopic, as in this case. This finding is visualised in 17-28% of ectopics, if transvaginal ultrasound is used . More commonly, signs are non-specific. Free pelvic fluid, especialy if echogenic, suggests a haemoperitoneum in this setting. The presence of a complex adnexal mass is not specific for ectopic, since endometriomas, haemorrhagic corpus luteum cysts and pelvic abscesses can have similar appearances. However, in the presence of a positive B-hcg and the absence of an intrauterine sac an ectopic pregnancy should be strongly suspected. An ectopic ‘tubal ring’ is described in 49% of ectopics and in 68% of unruptured ones. The tubal ring consists of concentric trophoblastic tissue surrounding the chorionic sac of the ectopic pregnancy. This tubal ring may be distinguished from a corpus luteum cyst by the fact that the corpus luteum cyst is located eccentrically within a rim of ovarian tissue. Doppler assessment reveals a markedly vascular ‘ring of fire’ appearance surrounding the gestation sac. This appearance is due to high velocity, low resistance, trophoblastic flow and is reported to be present in 5% of ectopic pregnancies. 2-3% of tubal ectopics occur in the interstitial portion of the fallopian tube, in the cornua of the uterus. Cornual ectopics tend to present later and are associated with more severe haemorrhage.

Differential Diagnosis List

Final Diagnosis

Live ectopic pregnancy

URL:	https://eurorad.org/case/770
DOI:	10.1594/EURORAD/CASE.770
ISSN:	1563-4086