Rectal ectopic pregnancy diagnosed through laparoscopy and pathological analysis: An extremely rare case report

Abstract

Rationale: Rectal ectopic pregnancy (EP) is an extremely rare subtype of abdominal pregnancy, posing significant diagnostic challenges due to its infrequent occurrence, atypical clinical manifestations, and imaging findings that mimic other medical conditions. Delayed diagnosis may lead to life-threatening complications such as intra-abdominal hemorrhage. This case highlights the importance of comprehensive laparoscopic exploration and pathological confirmation in identifying rare ectopic implantation sites.

Patient concerns: A 40-year-old female presented with a 1-day history of abdominal pain, 8-day vaginal spotting, and 39-day amenorrhea. Gynecological ultrasound revealed a mixed echogenic area posterior to the uterus, endometrial hyperechoic area, and bilateral fallopian tube thickening, with serum beta-human chorionic gonadotropin levels at 969.19 IU/L.

Diagnoses: Preoperative suspicion of EP was confirmed intraoperatively via laparoscopic exploration, which revealed a 0.5 cm rectal wall defect in the rectovaginal pouch with blood clots. Pathological analysis of pelvic clots identified chorionic villi, confirming rectal EP.

Interventions: Laparoscopic management included clot evacuation, electrocoagulation of the rectal defect, suture hemostasis, and postoperative oral mifepristone (50 mg bid) to prevent residual trophoblastic tissue.

Outcomes: Serum beta-human chorionic gonadotropin levels declined to negative within 3 weeks postoperatively, with no evidence of complications during follow-up.

Lessons: This case emphasizes the necessity of thorough laparoscopic examination of the pelvic and abdominal cavities in suspected EP to avoid missed diagnoses in concealed implantation sites, such as the rectal wall.

Keywords: case report; laparoscopic; pathological diagnosis; rectal ectopic pregnancy.

Figure 1.

Preoperative transvaginal ultrasound findings. (A) Sagittal view showing a mixed echogenic mass (arrowheads) posterior to the uterine body, composed of heterogeneous solid and cystic components. (B) Transverse view demonstrating an anechoic fluid collection (arrowheads) surrounding the uterus, indicative of intraperitoneal bleeding.

Figure 2.

Intraoperatively laparoscopic examination (A) indicates an accumulation of blood in the rectouterine trap, with bilateral tubes intact without rupture orifices, (B) removal of blood clots did not reveal any obvious lesions, (C) careful exploration reveals a rupture in the rectal surface.

Figure 3.

Pathological examination of pelvic blood clots (H&E staining) revealed chorionic villi tissues. H&E = hematoxylin-eosin staining.