The Journal of Emergency Medicine, Vol. 46, No. 5, pp. 685–686, 2014 Copyright Ó 2014 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$ - see front matter
http://dx.doi.org/10.1016/j.jemermed.2013.11.089
Visual Diagnosis in Emergency Medicine
CESAREAN SECTION SCAR ECTOPIC PREGNANCY Meaghan Marie Mackesy, MD, Jeffrey Forris Beecham Chick, MD, MPH, Nikunj Rashmikant Chauhan, MD, Jacob C. Mandell, MD, and Bharti Khurana, MD Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts Reprint Address: Jeffrey Forris Beecham Chick, MD, MPH, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115
INTRODUCTION Uterine scar ectopic pregnancy occurs when the conceptus implants in the myometrium at the site of a cesarean section scar. Misdiagnosis of this rare form of ectopic pregnancy can result in significant patient morbidity and mortality. CASE REPORT A 29-year-old G8P2 female presented to the Emergency Department with vaginal bleeding for 3 days. Physical examination was notable for a healed, low transverse cesarean section scar. Vital signs were within normal limits. A serum quantitative human chorionic gonadotropin was 9710 mlU/mL. Transabdominal and pelvic ultrasounds demonstrated a cystic structure with surrounding decidual reaction within the anterior myometrium at the site of cesarean section scar (Figure 1). Magnetic resonance imaging of the pelvis demonstrated decidual reaction extending into the scar, confirming a cesarean section scar ectopic pregnancy (Figure 2). The patient subsequently underwent successful dilation and evacuation. DISCUSSION
Figure 1. Transabdominal ultrasound images demonstrating a 1.6 0.9 0.8 cm cystic structure with surrounding decidual reaction and few internal echoes within the lower uterine segment (solid white arrows) at the site of cesarean section scar (dashed white arrow).
Complications of cesarean sections include future uterine rupture, placental abnormalities, and ectopic pregnancies
RECEIVED: 3 April 2013; FINAL SUBMISSION RECEIVED: 11 October 2013; ACCEPTED: 17 November 2013 685
686
M. M. Mackesy et al.
Figure 3. Schematic diagram of a cesarean section scar ectopic pregnancy demonstrating migration of the conceptus (solid red circle) into the myometrium through a small dehiscence in the cesarean scar (brown zigzag line). Figure 2. Axial T1-weighted magnetic resonance image of the pelvis with intravenous gadolinium and fat suppression demonstrating a 2.4 2.1 cm structure with a thickened enhancing wall (solid white arrows) representing decidual reaction extending posteriorly to the linear hypointense cesarean section scar (dashed white arrow), consistent with a cesarean section scar ectopic pregnancy.
(1,2). An ectopic pregnancy occurring within the scar from a previous cesarean section is considered to be the most rare form of ectopic pregnancy, with potentially catastrophic complications, including uterine rupture, disseminated intravascular coagulation, and death (1). Although uncommon, the incidence of cesarean section scar ectopic pregnancies is rising, thought to be due to the increased prevalence of cesarean sections (3). In addition, recent case series estimated the incidence of cesarean section scar ectopic pregnancies to be 1:2226 of all pregnancies, with a rate of 0.15% in women with a previous caesarean section, and a rate of 6.1% of all ectopic pregnancies in women who had at least one prior caesarean delivery (4). Such pregnancies are theorized to occur due to migration of the conceptus into the myometrium through a small dehiscence in the cesarean scar (Figure 3) (5). Pelvic ultrasound is the imaging modality of choice, with a sensitivity of 84.6% (6). Key findings include an embedded mass adjacent to an enlarged scar and thinning
of the myometrium (3,7). In cases of diagnostic uncertainty, magnetic resonance imaging can also be utilized (3). Therapeutic management is based on severity of symptoms and surgical experience. Options include expectant management, medical management with methotrexate, laparoscopy with wedge excision, and dilation and curettage. REFERENCES 1. Chazotte C, Cohen WR. Catastrophic complications of previous cesarean section. Am J Obstet Gynecol 1990;163:738–42. 2. Hemminki E, Merilainen J. Long-term effects of cesarean sections: ectopic pregnancies and placental problems. Am J Obstet Gynecol 1996;174:1569–74. 3. Osborn DA, Williams TR, Craig BM. Cesarean scar pregnancy sonographic and magnetic resonance imaging findings, complications, and treatment. J Ultrasound Med 2012;31(9):1449–56. 4. Seow KM, Huang LW, Lin YH, Lin MY, Tsai YL, Hwang JL. Cesarean scar pregnancy: issues in management. Ultrasound Obstet Gynecol 2004;23:247–53. 5. Jurkovic D, Hillaby K, Woelfer B, Lawrence A, Salim R, Elson CJ. First trimester diagnosis and management of pregnancies implanted into the lower uterine segment cesarean section scar. Ultrasound Obstet Gynecol 2003;21:220–7. 6. Rotas MA, Haberman S, Levgur M. Cesarean scar ectopic pregnancies. Obstet and Gynecol 2006;107(6):1373–81. 7. Weimin W, Wenqing L. Effect of early pregnancy on a previous lower segment cesarean section scar. Int J Gynaecol Obstet 2002; 77:201–7.
http://dx.doi.org/10.1016/j.jemermed.2013.11.089
Visual Diagnosis in Emergency Medicine
CESAREAN SECTION SCAR ECTOPIC PREGNANCY Meaghan Marie Mackesy, MD, Jeffrey Forris Beecham Chick, MD, MPH, Nikunj Rashmikant Chauhan, MD, Jacob C. Mandell, MD, and Bharti Khurana, MD Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts Reprint Address: Jeffrey Forris Beecham Chick, MD, MPH, Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115
INTRODUCTION Uterine scar ectopic pregnancy occurs when the conceptus implants in the myometrium at the site of a cesarean section scar. Misdiagnosis of this rare form of ectopic pregnancy can result in significant patient morbidity and mortality. CASE REPORT A 29-year-old G8P2 female presented to the Emergency Department with vaginal bleeding for 3 days. Physical examination was notable for a healed, low transverse cesarean section scar. Vital signs were within normal limits. A serum quantitative human chorionic gonadotropin was 9710 mlU/mL. Transabdominal and pelvic ultrasounds demonstrated a cystic structure with surrounding decidual reaction within the anterior myometrium at the site of cesarean section scar (Figure 1). Magnetic resonance imaging of the pelvis demonstrated decidual reaction extending into the scar, confirming a cesarean section scar ectopic pregnancy (Figure 2). The patient subsequently underwent successful dilation and evacuation. DISCUSSION
Figure 1. Transabdominal ultrasound images demonstrating a 1.6 0.9 0.8 cm cystic structure with surrounding decidual reaction and few internal echoes within the lower uterine segment (solid white arrows) at the site of cesarean section scar (dashed white arrow).
Complications of cesarean sections include future uterine rupture, placental abnormalities, and ectopic pregnancies
RECEIVED: 3 April 2013; FINAL SUBMISSION RECEIVED: 11 October 2013; ACCEPTED: 17 November 2013 685
686
M. M. Mackesy et al.
Figure 3. Schematic diagram of a cesarean section scar ectopic pregnancy demonstrating migration of the conceptus (solid red circle) into the myometrium through a small dehiscence in the cesarean scar (brown zigzag line). Figure 2. Axial T1-weighted magnetic resonance image of the pelvis with intravenous gadolinium and fat suppression demonstrating a 2.4 2.1 cm structure with a thickened enhancing wall (solid white arrows) representing decidual reaction extending posteriorly to the linear hypointense cesarean section scar (dashed white arrow), consistent with a cesarean section scar ectopic pregnancy.
(1,2). An ectopic pregnancy occurring within the scar from a previous cesarean section is considered to be the most rare form of ectopic pregnancy, with potentially catastrophic complications, including uterine rupture, disseminated intravascular coagulation, and death (1). Although uncommon, the incidence of cesarean section scar ectopic pregnancies is rising, thought to be due to the increased prevalence of cesarean sections (3). In addition, recent case series estimated the incidence of cesarean section scar ectopic pregnancies to be 1:2226 of all pregnancies, with a rate of 0.15% in women with a previous caesarean section, and a rate of 6.1% of all ectopic pregnancies in women who had at least one prior caesarean delivery (4). Such pregnancies are theorized to occur due to migration of the conceptus into the myometrium through a small dehiscence in the cesarean scar (Figure 3) (5). Pelvic ultrasound is the imaging modality of choice, with a sensitivity of 84.6% (6). Key findings include an embedded mass adjacent to an enlarged scar and thinning
of the myometrium (3,7). In cases of diagnostic uncertainty, magnetic resonance imaging can also be utilized (3). Therapeutic management is based on severity of symptoms and surgical experience. Options include expectant management, medical management with methotrexate, laparoscopy with wedge excision, and dilation and curettage. REFERENCES 1. Chazotte C, Cohen WR. Catastrophic complications of previous cesarean section. Am J Obstet Gynecol 1990;163:738–42. 2. Hemminki E, Merilainen J. Long-term effects of cesarean sections: ectopic pregnancies and placental problems. Am J Obstet Gynecol 1996;174:1569–74. 3. Osborn DA, Williams TR, Craig BM. Cesarean scar pregnancy sonographic and magnetic resonance imaging findings, complications, and treatment. J Ultrasound Med 2012;31(9):1449–56. 4. Seow KM, Huang LW, Lin YH, Lin MY, Tsai YL, Hwang JL. Cesarean scar pregnancy: issues in management. Ultrasound Obstet Gynecol 2004;23:247–53. 5. Jurkovic D, Hillaby K, Woelfer B, Lawrence A, Salim R, Elson CJ. First trimester diagnosis and management of pregnancies implanted into the lower uterine segment cesarean section scar. Ultrasound Obstet Gynecol 2003;21:220–7. 6. Rotas MA, Haberman S, Levgur M. Cesarean scar ectopic pregnancies. Obstet and Gynecol 2006;107(6):1373–81. 7. Weimin W, Wenqing L. Effect of early pregnancy on a previous lower segment cesarean section scar. Int J Gynaecol Obstet 2002; 77:201–7.
