File:Blob sign of ectopic pregnancy.svg

The otherwise healthy 31 year old woman had begun to feel symptoms of pregnancy, including breast tenderness. A urine pregnancy was positive. However, three months prior she had a Mirena intrauterine device inserted, which thus made the probability of an intrauterine pregnancy very unlikely.

The vaginal ultrasonography showed the image as displayed, including a spherical mass (or "blob") close to the right ovary. The intrauterine device was in optimal location within the uterine cavity. There was no trace of a gestational sac within the uterus. Serum hCG was 1254 IU/L, at which level any intrauterine pregnancy is usually seen with the ultrasonography device. A cross-section of the Mirena is shown within the uterine cavity, leaving an ultrasound shadow distally to it.

A diagnosis of ectopic pregnancy was made. Laparoscopy was performed, and showed a fallopian tube that was swollen and bluish as by circulatory obstruction. There was 40-50 milliliters of fluid within the rectouterine pouch and around the uterus. The affected tube was removed by salpingectomy.