Ultrasonographic diagnosis and laparoscopic management of an interstitial ectopic pregnancy: A case report and literature review

Interstitial ectopic pregnancy is a rare yet potentially life‑threatening type of ectopic gestation, representing ~2‑4% of all ectopic pregnancies. As implantation occurs within the interstitial portion of the fallopian tube, the clinical presentation is often delayed, and the risk of a catastrophic hemorrhage is increased in the event that rupture occurs due to its intramural location. Early and accurate diagnosis with high‑resolution transvaginal ultrasonography (TVUS) is thus essential to improve outcomes and preserve fertility. The present case report describes the clinical course of a 35‑year‑old woman (gravida 2, para 1) who presented with prolonged vaginal bleeding and recent‑onset hypogastric pain. Serum β‑human chorionic gonadotropin (β‑hCG) levels plateaued just below 1,000 mIU/ml. TVUS revealed an empty uterine cavity, a thin endometrium and an eccentrically located, mixed‑echogenicity mass within the right uterine cornu, clearly separate from the endometrial cavity. Key sonographic findings included the interstitial line sign, marked asymmetric thinning of the myometrial mantle surrounding the gestational sac to <5 mm and the absence of an adjacent endometrium. Color Doppler imaging demonstrated mild peripheral vascularity. Emergency laparoscopy confirmed an unruptured interstitial pregnancy lateral to the right round ligament. A laparoscopic wedge resection of the interstitial segment was successfully performed, with local vasopressin administration to minimize intraoperative blood loss. The post‑operative course of the patient was uneventful, with a rapid decline in β‑hCG levels and no requirement for adjuvant methotrexate therapy. On the whole, the present case report underscores the critical role of high‑resolution TVUS in the early diagnosis of interstitial pregnancy, and highlights the safety and efficacy of minimally invasive laparoscopic excision in hemodynamically stable patients with unruptured interstitial gestations. Early recognition and individualized surgical management are essential for optimizing clinical outcomes and preserving fertility in this rare condition.