the prevalence of ectopic pregnancy is high in societies in which women delay childbearing , with increased use of assisted reproductive technology ( art ) and with increased incidence of pelvic inflammatory disease caused by chlamydia and gonococcal bacteria . the risk of rupture of the uterus tends to increase beyond 12 weeks of amenorrhea , and the rupture of the ectopic part occurs in 20% of ectopic pregnancies beyond 12 weeks of gestational age . developing better methods for earlier diagnosis would decrease morbidity and increase the chance of successful laparoscopic surgery . in this paper , we present the case of a patient with tubal stump pregnancy . the patient was a 26-year - old japanese woman , gravida 4 , parity 1 , who had a medical history of laparoscopic surgery for right tubal pregnancy two years ago , and no remarkable family history . no gestational sac was detected in the uterus by transvaginal sonography , even at 6 weeks 0 days gestational age . however , the level of human chorionic gonadotropin ( hcg ) in the patient s blood was elevated to 8,900 miu / ml , and a gestational sac - like mass was found outside of the uterus by echography ( fig . 1 ) . based on these test results , ectopic pregnancy was strongly suspected , and the patient was suggested to undergo laparoscopic surgery . 2 ) , and we diagnosed it as tubal stump pregnancy . before resection of the ectopic part , we injected vasopressin surrounding the ectopic lesion to decrease blood flow . the ectopic part was removed with an advanced bipolar sealing device , ligasure ( covidien , manhattan ) , and the operative wound was sutured with absorbable vicryl ( ethicon , new jersey ) for uterine wall repair ( fig . 4 ) , but pathological findings revealed chorionic villi around the removed tubal stump , confirming the diagnosis of tubal stump pregnancy ( fig . after the surgery , the level of hcg in the blood decreased and the patient recovered uneventfully . recently , the frequency of ectopic pregnancy has tended to increase because of delayed childbearing , the increased use of art , and an increase in sexually transmitted diseases.1 it is reported that the incidence of ectopic pregnancy is approximately 1.3%2% of all pregnancies.2 more than 90% of ectopic pregnancies are detected in the tubal ampulla , and approximately 2.5% of cases occur in the interstitial position.3 ko et al reported that tubal stump pregnancy after tubectomy is extremely rare , with a prevalence of about 0.4%.1 there are two hypotheses for the pathogenesis of tubal stump pregnancy . one is the external chemotactic theory , which postulates that a foramen is formed at the tubal stump and a fertilized ovum coming from the intra - abdomen implants into the tubal stump portion.1,4 the other theory is that an embryo coming from the normal contralateral fallopian tube implants in the tubal stump.5,6 in this case , we could not see any foramen on the tubal stump , and hence the latter theory is applicable . however , in some cases , the diagnosis of tubal stump pregnancy is difficult because the tubal stump portion is near the ovary , and hence , the ovarian follicle is mistaken for a tubal stump pregnancy . moreover , it is thought that many doctors pay less attention to the tube in which patients have already undergone tubectomy because of ectopic pregnancy . lau and tulandi proposed three sonographic criteria for interstitial and tubal stump pregnancies : ( 1 ) an empty uterine cavity , ( 2 ) a chorionic sac seen separately and > 1 cm from the most lateral edge of the uterine cavity , and ( 3 ) a thin myometrial layer surrounding the chorionic sac.7 using these parameters , they found that the diagnosis was relatively specific ( 88%93% ) , but on the other hand , the sensitivity was only 40% for the diagnosis of interstitial and tubal stump pregnancies . timor - tritsch et al advocate an  interstitial line sign  for the diagnosis of interstitial and tubal stump pregnancies.8 this sign represents the visualization of an echogenic line extending into the abutting interstitial ectopic mass of the tubal mid - portion . in small - sized interstitial pregnancies , the line may represent the interstitial lesion of the tube . in large - sized interstitial pregnancies the diagnosis of interstitial pregnancy is 80% sensitive and 98% specific with the  interstitial line sign  technique . lau and tulandi reported that the overall success rates in surgical treatment reached 100% and that of methotrexate management was 83%.7 the operation method for tubal stump pregnancy is almost the same as that of interstitial pregnancy . the difficulty level of laparoscopic operation for interstitial and tubal stump pregnancy is higher than that of common laparoscopic tubectomy , and hence , the selection of operative method depends on the surgeon s preference and expertise . there are several reports of successful laparoscopic operation for interstitial and tubal stump pregnancy using an advanced bipolar device and injecting diluted vasopressin into the uterus.911 sherer et al recommend clamping the adjacent uterine wall to the interstitial pregnancy with long - jaw forceps before incising the cornua.12 on the other hand , there are reports of using hysteroscopic surgery for interstitial and tubal stump ectopic pregnancy.13 however , the efficiency and long - term prognosis for selecting hysteroscopic surgery are unknown . in this case , we injected vasopressin into the uterus surrounding the ectopic part and removed the ectopic lesion from the tubal stump using an advanced bipolar sealing device , ligasure . we successfully performed the operation for this patient with tubal stump pregnancy . any subsequent pregnancy after operation for tubal stump pregnancy should be followed up carefully and cesarean delivery at term may be safer and help decrease the risks of uterine rupture during labor . in summary laparoscopic surgery might be the first - line treatment for a hemodynamically stable patient with interstitial pregnancy of a small size . sometimes , the accurate diagnosis for this type of ectopic pregnancy is difficult ; therefore , we have to pay much attention to the possibility of tubal stump pregnancy when we diagnose the ectopic pregnancy .