Atypical presentation of a large interstitial pregnancy.

We report the case of a 20-year-old female who presented to the ER with a 1-week history of worsening abdominal pain and intermittent vaginal bleeding for the previous 5 days. Physical exam was notable for bilateral adnexal tenderness and a closed cervix without motion tenderness or discharge. Laboratory data demonstrated a beta HCG level of 7,787 IU/L, and pelvic ultrasound with transvaginal imaging was subsequently performed. Neither an adnexal mass nor a normal intrauterine pregnancy was demonstrable; however, a focal right fundal 7-cm area of heterogeneous echogenicity was observed. Initial findings were felt indeterminate with considerations including potential degenerating leiomyoma coexistent with a nonvisualized intrauterine pregnancy, ectopic pregnancy, or recent spontaneous abortion versus atypical interstitial ectopic pregnancy. The patient, initially declining further clinical intervention, returned within 24 h with continued pain. A repeat ultrasound demonstrated a relatively static and unchanged appearance with only a minimal concurrent interval increase in beta HCG levels. MRI was performed for further elucidation and demonstrated a heterogeneously hypervascular right fundal interstitial 6-cm mass, which, in the clinical context, was most suspicious for an ectopic pregnancy. Confirmatory laparoscopic cornual wedge resection and salpingectomy was subsequently performed.