Diagnostic dilemmas of an eccentrically located gestation sac: role of 3D ultrasound


  • Selvaraj Ravi Lakshmy Department of Fetal Medicine, Shri Lakshmi Clinic and Scan Centre, Krishnagiri, Tamil Nadu, India
  • Thasleem Ziyaulla Department of Fetal Medicine, Shri Lakshmi Clinic and Scan Centre, Krishnagiri, Tamil Nadu, India
  • Shobana Umapathy Department of Fetal Medicine, Shri Lakshmi Clinic and Scan Centre, Krishnagiri, Tamil Nadu, India




Angular pregnancy, Cornual pregnancy, Interstitial pregnancy, 3D ultrasound


Background: Differential diagnosis of an eccentrically located sac includes interstitial pregnancy, true cornual pregnancy and angular pregnancy which may all look similar on 2D (two dimensional) ultrasound. Interstitial pregnancy is associated with a higher maternal mortality and needs to be differentiated from true cornual pregnancy and angular pregnancy. This paper is an illustration of the role of 3D (three dimensional) ultrasound in differential diagnosis and management of the three entities.

Methods: 2D and 3D ultrasound findings were analyzed in 10 cases of eccentrically located sac. The role of 3D ultrasound in differentiating the three entities had been evaluated.

Results: The presence of an eccentrically located gestation sac with incomplete or asymmetric myometrial tissue less than 5 mm in thickness on 2D and the coronal sections obtained from 3D scans were used for diagnosis of interstitial pregnancy in three cases. 2 cases of angular pregnancy were diagnosed based on the finding of sac located in one of the lateral angles of the uterus with broad based connection to the endometrium. 2 cases of cornual pregnancy one intrauterine in a bicornuate uterus and the other in a rudimentary horn has been described. One heterotopic pregnancy and two other cases where a cornual fibroid mimics interstitial pregnancy is also illustrated.

Conclusions: The role of 3D ultrasound in differentiating the three entities and the key findings in obtaining the precise diagnosis are emphasized. Routine usage of 3D ultrasound in all cases of eccentrically located gestational sac is recommended.


Ross R, Lindheim SR, Olive DL, Pritts EA. Cornual gestation: a systematic literature review and two case reports of a novel treatment regimen. J Min Inv Gynecol. 2006;13:74-8.

Tulandi T, Al-Jaroudi D. Interstitial pregnancy: results generated from the Society of Reproductive Surgeons registry. Obstet Gynecol. 2004;103:47-50.

Stovall TG, McCord ML. Early pregnancy loss and ectopic pregnancy. In: Berek JS, Adashi EY, Hillard PA, editors. Novak’s Gynecology. 12th ed. Baltimore: Williams and Wilkins; 1996:487-524.

Tulandi T, Saleh A. Surgical management of ectopic pregnancy. Clin Obstet Gynecol. 1999;42(1):31-8.

Faraj R, Steel M. Review Management of cornual (interstitial) pregnancy. TOG. 2007;9(4):249-55.

Patil M. Ectopic pregnancy after infertility treatment. J Hum Reprod Sci. 2012;5(2):154-65.

Nardo LG. The dilemma of recurrent ectopic pregnancy after tubal surgery and in-vitro fertilization. What to do? Reprod Biomed Online. 2005;10:300.

Tanaka Y, Mimura K, Kanagawa T, Kajimoto E, Takahashi K, Kakigano A, et al. Three-dimensional sonography in the differential diagnosis of interstitial, angular, and intrauterine pregnancies in a septate uterus. J Ultrasound Med. 2014;33:2031-5.

Tanaka Y, Mimura K, Kanagawa T. Interstitial pregnancy resulting in a viable infant coexistent with massive perivillous fibrin deposition: a case report and literature review. AJP Rep. 2014;4:29-32.

Kalidindi M, Shahid A, Odejinmi F. Expect the unexpected: The dilemmas in the diagnosis and management of interstitial ectopic pregnancy: case report and literature review. Gynecol Minimal Inv Ther. 2016;5(1):35-7.

Timor-Tritsch IE, Monteagudo A, Matera C, Veit CR. Sonographic evolution of cornual pregnancies treated without surgery. Obstet Gynecol. 1992;79:1044-9.

Ackerman TE, Levi CS, Dashefsky SM, Holt SC, Lindsay DJ. Interstitial line: sonographic finding in interstitial (corneal ectopic pregnancy. Radiol. 1993;189:83-7.

Hafner T, Aslam N, Ross JA, Zosmer N, Jurkovic D. The effectiveness of non-surgical management of early interstitial pregnancy: a report of ten cases and review of the literature. Ultrasound Obstet Gynecol. 1999;13:131-6.

Jurkovic D, Mavrelos D. Catch me if you scan: ultrasound diagnosis of ectopic pregnancy. Ultrasound Obstet Gynecol. 2007;30(1):1-7.

Hamouda ESM, Littooij AS, Thia EW, Ong CL. Ruptured interstitial ectopic pregnancy at 18 weeks gestation diagnosed by MRI: a case report. JRCR. 2013;7(10):34-42.

Kun WM, Tung WK. On the look out for a rarity–interstitial/cornual pregnancy. Eur J Emerg Med. 2001;8:147-50.

DeWitt C, Abbott J. Interstitial pregnancy: a potential for Misdiagnosis of ectopic pregnancy with emergency department ultrasonography. Ann Emerg Med. 2002;40:106-9.

Petersen KR, Larsen GK, Nørring K, Jensen FR. Misdiagnosis of interstitial pregnancy followed by uterine cornual rupture during induced midtrimester abortion. Acta Obstet Gynaecol Scand. 1992;71:316e318.

Chan LYS, Fok WY, Yuen PM. Pitfalls in diagnosis of interstitial pregnancy. Acta Obstet Gynaecol Scand. 2003;82:867e870.

MacRae R, Olowu O, Rizzuto MI, Odejinmi F. Diagnosis and laparoscopic management of 11 consecutive cases of cornual ectopic pregnancy. Arch Gynaecol Obstet. 2009;280:59e64.

Moawad NS, Mahajan ST, Moniz MH, Taylor SE, Hurd WW. Currentdiagnosis and treatment of interstitial pregnancy. Am J Obstet Gynecol. 2010;202:15-29.

Sharma N, Upasana R. An ectopic pregnancy in the tubalinterstitium: Beware! J Clin Diagn Res. 2013;7:160-2.

Cucinella G, Calagna G, Rotolo S, Granese R, Saitta S. A interstitial pregnancy: a ‘road map’ of surgical treatment basedon a systematic review of the literature. Gynecol Obstet Invest. 2014;78:141-9.

Practice Committee of American Society for Reproductive Medicine. Medical treatment of ectopic pregnancy: a committee opinion. Fertil Steril. 2013;100:638-44.

Jermy K, Thomas J, Doo A, Bourne T. The conservative management of interstitial pregnancy. BJOG. 2004;111:1283-8.

Lau S, Tulandi T. Conservative medical and surgical management of interstitial ectopic pregnancy. Fertil Steril. 1999;72:207-15.

Soriano D, Vicus D, Mashiach R, Schiff E, Seidman D, Goldenberg M. Laparoscopic treatment of cornual pregnancy: a series of 20 consecutive cases. Fertil Steril. 2008;90:839-43.

Singh N, Tripathi R, Mala YM, Batra A. Diagnostic dilemma incornual pregnancy-3D ultrasonography may Aid!! J Clin Diagn Res. 2015;9:12-3.

Wang J, Huang D, Lin X, Saravelos SH, Chen J. Incidence of interstitial pregnancy after in vitro fertilization/embryo transfer and the outcome of a consecutive series of 38 cases managed by laparoscopic cornuostomy or cornual repair. J Minim Invasive Gynecol. 2016;9:134-5.

Siow A, Ng S. Laparoscopic management of 4 cases of recurrent cornual ectopic pregnancy and review of literature. J Minim Invasive Gynecol. 2011;18:296-302.

Surbone A, Cottier O, Vial Y, Francini K, Hohlfeld P. Interstitial pregnancies' diagnosis and management: an eleven cases series. Swiss Med Wkly. 2013;143:13736.

Sills ES, Perloe M, Kaplan CR, Sweitzer CL, Morton PC, Tucker MJ. Uncomplicated pregnancy and normal singleton delivery after surgical excision of heterotopic (cornual) pregnancy following in vitro fertilization/embryo transfer. Arch Gynecol Obstet. 2002;266:181-4.

Ben-Ami I, Panski M, Ushakov F, Vaknin Z, Herman A, Raziel A. Recurrent heterotopic pregnancy after bilateral salpingectomy in an IVF patient: case report. J Assist Reprod Genet. 2006;23:333-5.

Auamkul S. Rupture of gravid uterus after cornual resection. A case report. J Reprod Med. 1970;5(5):218-20.

Tulandi T, Vilos G, Gomel V. Laparoscopic treatment of interstitial pregnancy. Obstet Gynecol. 1995;85(3):465-7.

Su CF, Tsai HJ, Chen GD, Shih YT, Lee MS. Uterine rupture at scar of prior laparoscopic cornuostomy after vaginal delivery of a full-term healthy infant. J Obstet Gynaecol Res. 2008;34(4 Pt 2):688-91.

Jansen RP, Elliott PM. Angular intrauterine pregnancy. Obstet Gynecol. 1981;58:167-75.

Alves JA, Alves NG, AlencarJúnior CA, Feitosa FE, da Silva Costa F. Term angular pregnancy: successful expectant management. J Obstet Gynaecol Res. 2011;37:641-4.

Chang FW, Yu MH, Chen WH. An angular pregnancy of a bicornuate uterus. Int J Gynaecol Obstet. 2003;81:219-20.

Grant A, Murji A, Atri M, Epid D. Can the presence of a surrounding endometrium differentiate eccentrically located intrauterine pregnancy from interstitial ectopic pregnancy? J Obstet Gynaecol Can. 2017;39(8):627-34.

Parker RA, Yano M, Tai AW, Friedman M, Narra VR, Menias CO, et al. MR imaging findings of ectopic pregnancy: a pictorial review. Radiograph. 2012;32(5):1445-60.

Jayasinghe Y, Rane A, Stalewski H, Grover S. The presentation and early diagnosis of the rudimentary uterine horn. Obstet Gynecol. 2005;105:1456-67.

Mavrelos D, Sawyer E, Helmy S, Holland T, Ben-Nagi J, Jurkovic D. Ultrasound diagnosis of ectopic pregnancy in thenon-communicating horn of a unicornuate uterus (cornual pregnancy). Ultrasound Obstet Gynecol. 2007.

DeNicola RR, Peterson MR. Pregnancy in rudimentary horn of uterus. Am J Surg. 1947;73:382-6.

Nahum GG. Rudimentary uterine horn pregnancy. The 20th century worldwide experience of 588 cases. J Reprod Med. 2002;47:151-63.

Martin JN, McCaulJFt. Emergent management of abdominal pregnancy. Clin Obstet Gynecol. 1990;33:438-47.

Cunningham FG, Leveno KJ, Bloom SL, Hauth JC, Rouse DJ, Spong CY. Reproductive tract abnormalities. In: Cunningham FG, Leveno KJ, Bloom SL, Hauth JC, Rouse DJ, Spong CY (eds.) Williams Obstetrics. 23rd ed. New York, NY: McGraw-Hill; 2010:890-911.

Saravelos SH, Cocksedge KA, Li TC. Prevalence and diagnosis of congenital uterine anomalies in women with reproductive failure: a critical appraisal. Hum Reprod Update. 2008;14:415-29.

Bermejo C, Martínez Ten P, Cantarero R. Three-dimensional ultrasoundin the diagnosis of müllerian duct anomalies and concordance withmagnetic resonance imaging. Ultrasound Obstet Gynecol. 2010;35:593-601.

Ogu RN, Enyindah C, Orazulike N, Okpani AO. Submucous uterine fibroid mimicking ruptured ectopic gestation: a case report. J Clin Diagn Res. 2014;8(7):OD08-9.






Original Research Articles