Abortive Tubal Stump Pregnancy: Two Case Reports with Diagnostic Challenges and High Risk of Persistent Ectopic Pregnancy

Background: Tubal stump pregnancy(TSP) is a rare ectopic pregnancy that occurs in patients after salpingectomy. We report two cases of a distinct clinical subtype characterized by spontaneous detachment of gestational tissue from the tubal stump, which we describe as “abortive TSP”. Cases: Two patients with a history of salpingectomy presented with abdominal pain and positive β-hCG. Case 1 was conceived naturally, with a history of amenorrhea for 34 days. Case 2 was a pregnancy achieved by in vitro fertilization and embryo transfer (IVF-ET), with two fresh embryos transferred 21 days prior to admission. Preoperative ultrasound showed no intrauterine pregnancy, no obvious mass at the uterine cornua or adnexa, but revealed hemoperitoneum. Intervention: Both patients underwent emergency laparoscopy. Active bleeding from the tubal stump was identified, with no distinct mass visible. Case 1 received evacuation of pelvic hematocele, suture of the tubal stump and uterine cornua. Typical chorionic villi were identified in the pelvic hematocele. Case 2 underwent removal of one intact chorionic villus from the tubal stump surface, evacuation of pelvic hematocele with identification of a second chorionic villus, suture of the tubal stump and uterine cornua. Outcomes: Histopathological examination confirmed chorionic villi in the evacuated pelvic tissue. Primary implantation within the tubal stump wall could not be histologically confirmed. In Case 1, serial β-hCG levels declined steadily to within the normal range during follow-up. In Case 2, β-hCG increased during follow-up, consistent with persistent ectopic pregnancy(PEP), and the condition resolved after treatment with methotrexate (MTX). Conclusion: Abortive TSP is a rare and easily misdiagnosed condition. In post-salpingectomy patients with positive β-hCG and hemoperitoneum, consider TSP and/or abortive TSP; inspect the stump carefully and ensure structured postoperative β-hCG surveillance to detect persistent trophoblastic tissue.