CHRONIC ECTOPIC PREGNANCE ULTRASONIC DIAGNOSIS by William F. Rogers, MD; Michael Shaub, MD and Robert Wilson, MD
ABSTRACT The classical ultrasonic description of a chronic ectopic pregnancy is a slightly enlarged uterus with uniform internal echoes and no evidence of an intrauterine pregnancy, combined with an extrauterine semicystic mass, gestational sac, or fetal structures. It is our experience that the ultrasonographer more commonly finds a midline pelvic mass containing irregular echo patterns and cystic areas. The mass may also be associated with abdominal or pelvic fluid and obliteration of normal anatomical structures. We wish to emphasize these variations from the classical description with illustrations that demonstrate the differences in the ultrasonic presentation of chronic ectopic pregnancy.
Indexing Words Chronic Ectopic Pregnancy Diagnostic Ultrasound Obstetrical and Gynecological Studies
A brief explanation of pathological changes with ectopic pregnancy is important in understanding the ultrasonic presentations. Ectopic pregnancy is similar to a normal pregnancy, with hormonal stimulation causing uterine hypertrophy and the development of the decidua. The endometrial changes appear almost identical to a normal intrauterine pregnancy except for the absence of chorionic villi. The conditions for trophoblastic growth in the wall of the tube are different in comparison to growth in a normal intrauterine pregnancy. The paucity of decidual development augments vascular penetration and invasion of the muscularis. Hematomas often result after rupture into adjacent structures. This leads to early separation and death of the embryo with subsequent degeneration of the trophoblast, and absorption, abortion, or passage of fetal parts. In a chronic ectopic pregnancy the process persists and becomes walled off with organization. Chronic ectopic pregnancies more often have irregular recurrent vaginal bleeding, fever, and palpable adnexal masses. An “acute” ectopic pregnancy usually From the Department of Radiology of the LAC-USC Medical Center, Section of Diagnostic Ultrasound, Los Angeles, Califm-
nia. For reprints contact: Robert Wilson. M.D., Department of Radiology of the LAC-USC Medical Center, Section of Diagnostic Ultrasound, 1200 North State Street. Los Angeles. California 80033. VOLUME 5. NUMBER 4
Pelvic Masses
denotes a combination of abrupt pain, syncope, or shock from massive hemorrhage. Kobayashi describes uterine and extrauterine findings in the classical ultrasonic presentation of ectopic pregnancy. Associated with the uterine findings are a) ,diffuse homogeneous uterine echoes, b) uterine enlargement, c) absence of an intrauterine pregnancy. Extrauterine findings are directed toward demonstration of a) an ectopic gestational sac or fetal parts, b) a cystic appearing irregular mass containing internal echoes, and c) a hernoperitoneum evidenced by a cystic mass in the cul de sac with or without an echo pattern similar to ascites. Understandably, visualization of an extrauterine fetal head is diagnostic but rarely occurs. Figure 1A shows the classical ultrasonic picture of an ectopic pregnancy with a slightly enlarged uterus with diffuse internal echoes, but without evidence of an intrauterine pregnancy. To the right of the midline (1B) a semicystic adnexal mass is evident. At surgery, an ectopic pregnancy with numerous adhesions was discovered in the right fallopian tube. There was no evidence of rupture. Culdocentesis before surgery had been negative. This patient demonstrates many of the classical ultrasonic findings of chronic ectopic pregnancy. Combining these findings with the clinical impressions and the 2 87
FIGURE 1A. Longitudinal section 2 cm to the left of midline. The uterus is slightly enlarged with diffuse homogeneous internal echoes. No fetal or gestational structures are identified within the uterus. The vertical linear shadow in the central portion of the picture i s an artifact. U = uterus, 6 = bladder, S = symphysis pubis.
FIGURE 18. Longitudinal section 4 cm to the right of midline. A 6 cm semicystic adnexal mass is identified posterior and slightly superior to the bladder. The vertical linear shadow in the central portion of the picture is an artifact. B = bladder, M =semicystic, S = symphysis pubis.
FIGURE 2A. Midline longitudinal section demonstrating a large pelvic mass with irregular, nonuniform echoes. The normal pelvic structures are obscured by the extensive necrosis and inflammatory reaction. B = bladder, S = symphysis pubis, U = umbilicus.
FIGURE 28. Transverse section through the semicystic mass.
The range markers to the right of the picture indicate 1 cm intervals. left side.
M
= midline,
R = materal right side, L = maternal
positive pregnancy test should lead to the diag- phasize the differences in ultrasonic presentanosis. One must be critical in evaluating a posi- tions. Often a pelvic mass is demonstrated that tive pregnancy test. Reportedly, pregnancy tests cannot be precisely defined but which usually are positive in approximately one-half of the incorporates the uterus. Figure 2A demonstrates patients with chronic ectopic pregnancy (3). the midline longitudinal section and a transverse Arkin (5) observed false-positive results with the section (2B)through an infected chronic ectopic latex-particle agglutination-inhibition test in pat- pregnancy. In comparison with Figure 1, the echoes within the pelvic mass are irregularly ients with tubo-ovarian acscess. Frequently, chronic ectopic pregnancies will distributed, nonuniform, and of distinctly not present in the previously described classi- different quality than the uterine echoes visuacal description. The following examples em- lized in Figure l. The extensive necrosis and 258
JOURNAL OF CLINICAL ULTRASOUND
FIGURE 3. Midline longitudinal section showing an irregular semicystic pelvic mass associted with free fluid within the cul de sac and anterior peritoneal cavity. B = bladder, U = umbilicus, S = symphysis pubis, F = free fluid.
inflammatory reaction obscure the normal anatomical structures and render their boundaries difficult to ascertain. The echo pattern from this mass is distinctly different from a hydatiform mole and should not be confused with that diagnosis. Other ultrasonic findings might be useful in aiding one to diagnose a chronic ectopic pregnancy. As previously discussed, the tendency to rupture and hemorrhage often produces irregular collections of fluid within the pelvis or abdomen. The longitudinal section in Figure 3 demonstrates an irregular mixed or semicystic pelvis mass with associated free fluid within the cul de sac and anterior peritoneal cavity. This free fluid ultimately proved to be blood associated with clots within these areas. The lack of definition of normal uterine and adnexal structures is again evident. The echo pattern within the semicystic mass posterior to the bladder is a result of extensive necrosis, hemorrhage, and inflammatory reaction. In Figure 4, three views of an ultrasound examination demonstrate how the chronicity, excessive inflammatory reaction, and tendency to rupture with hemorrhage can result in confusing images because of obliteration of normal anatomical structures. The examples illustrate the extensive involvement of pelvic structures and complexity of ultrasonic findings associated with chronic ectopic pregnancy. At surgery a normal-sized uterus was found which had massive adhesions to the anterior peritoneum, posterior bladder, large and small bowel, and both adnexal areas. There was a large volume of VOLUME 6. NUMBER 4
FIGURE 4A. A midline longitudinal sectim illustrating what appear to be an enlarged uterus with irregular internal echoes. Note the illdefined margins of the mass. No definite gestational or fetal structures are identified. B = bladder, M = mass, S = symphysis pubis, U = umbilicus.
FIGURE 46. Longitudinal section 4 cm to the right of midline demonstrating portions of the mass having solid and cystic areas within it. B = bladder, M = mass, S = symphysis pubis, U = umbilicus.
blood in the pelvis, with organized clots and fibrin involving a left adnexal mass, the uterus, and the right ovary. Upon removal and sectioning of the left adnexal mass, a gestational sac was located within, but neither ovarian nor fallopian tissue could be identified. The clinician often encounters difficulty in differentiating among various types of pelvic masses. The ultrasonic examination is useful in demonstrating the disease entity. Firgure 5 demonstrates a pelvic mass with ill-defined borders. This patient had a gestational age of 289
FIGURE 4C. Another portion of the mass is demonstrated in this section taken 3 cm to the left of midline. The lack of normal pelvic structures is evident. Again identified are the irregular echoes and cystic areas. B = bladder, M = mass, S = symphysis pubis.
FIGURE 5. This longitudinal section is 3 cm to the right of midline. The ill-defined pelvic mass has irregular echoes and might easily be confused with uterine leiomyomata. B = bladder, M = mass, S = symphysis pubis.
nine weeks but the pelvic mass was approximately that of a 16 week-sized uterus. Culdocentesis was negative, but the pregnancy test was positive. The patient was subsequently diagnosed as having a chronic ectopic pregnancy. The important differentiating points are the echo pattern which is not characteristic of a volar pregnancy but which might easily be confused with uterine leiomyomata, the lack of definition of normal uterine and pelvic structures with repeated ultrasonic scans, the positive pregnancy test, and lack of intrauterine gestational or fetal structures. Several descriptions of the classical ultrasonic presentation of chronic ectopic pregnancies have been reported by various authors ( 1 , 6-8). The ultrasonographer will frequently encounter variations of the classical presentation and will very rarely be able to identify fetal structures outside of the uterus. The ultrasonic images are a result of a combination of events and structures. The events would include ectopic implantation of the fertilized ovum, erosion, rupture with hemorrhage, inflammatory reaction, organization, and formation of adhesions. The structures would include any or all of the pelvic anatomy, hematomas, and inflammatory mass. Obliteration of normal pelvic structures, cystic areas with or without free abdominal or pelvic fluid, and an ill-defined pelvic mass with irregular echo patterns should alert theultrasonographer to consider chronic ectopic pregnancy.
Correlation with the laboratory and clinical data should assist in the correct diagnosis.
260
ACKNOWLEDGMENT
The authors sincerely appreciate the assistance of Eileen de la Vega and Marie Andrianos in producing this manuscript and the technical assistance of Marcia Fodran, Sally Smith, and Elvira Vinson. REFERENCES 1. Kobayashi M. Hellman LM, Cromb E, and Chesley LC: Ectopic Pregnancy. In Atlas of Ultrasonography in Obstetrics and Gynecology. New York, Meredith Corporation, 1972, p. 137. 2. Jarcho J: Ectopic pregnancy: With special reference to abdominal pregnancy. Am J Surg 77:273,1945. 3. Case Records of the Massachusettes General Hospital (Case 11-1976). N Engl J Med 294:600,1976. 4. Hoerner MT: Bilateral simultaneous tuba1 pregnancy: Review of literature and report of case. Am J Surg 91:358,1956. 5. Arkin C, Noto TA: A False positive immunologic pregnancy test with tubo-ovarian acscess. Am J Clin Path 58:314,1972. 6. Cochrane WJ: Ultrasound in gynecology. Radio1 Clin North Am 13:463,1975. 7. Goldberg BB, Kotler MN, Ziskin MC, and Waxham RD: Ectopic Pregnancy. In Diagnostic Uses of Ultrasound. New York, Grune and Stratton, 1975, p. 384. 8. Brown RE: Ultrasonography: Basic Principles and Clinical Applications. St. Louis, Warren H. Green, Inc., 1975.
JOURNAL O F CLINICAL ULTRASOUND
ABSTRACT The classical ultrasonic description of a chronic ectopic pregnancy is a slightly enlarged uterus with uniform internal echoes and no evidence of an intrauterine pregnancy, combined with an extrauterine semicystic mass, gestational sac, or fetal structures. It is our experience that the ultrasonographer more commonly finds a midline pelvic mass containing irregular echo patterns and cystic areas. The mass may also be associated with abdominal or pelvic fluid and obliteration of normal anatomical structures. We wish to emphasize these variations from the classical description with illustrations that demonstrate the differences in the ultrasonic presentation of chronic ectopic pregnancy.
Indexing Words Chronic Ectopic Pregnancy Diagnostic Ultrasound Obstetrical and Gynecological Studies
A brief explanation of pathological changes with ectopic pregnancy is important in understanding the ultrasonic presentations. Ectopic pregnancy is similar to a normal pregnancy, with hormonal stimulation causing uterine hypertrophy and the development of the decidua. The endometrial changes appear almost identical to a normal intrauterine pregnancy except for the absence of chorionic villi. The conditions for trophoblastic growth in the wall of the tube are different in comparison to growth in a normal intrauterine pregnancy. The paucity of decidual development augments vascular penetration and invasion of the muscularis. Hematomas often result after rupture into adjacent structures. This leads to early separation and death of the embryo with subsequent degeneration of the trophoblast, and absorption, abortion, or passage of fetal parts. In a chronic ectopic pregnancy the process persists and becomes walled off with organization. Chronic ectopic pregnancies more often have irregular recurrent vaginal bleeding, fever, and palpable adnexal masses. An “acute” ectopic pregnancy usually From the Department of Radiology of the LAC-USC Medical Center, Section of Diagnostic Ultrasound, Los Angeles, Califm-
nia. For reprints contact: Robert Wilson. M.D., Department of Radiology of the LAC-USC Medical Center, Section of Diagnostic Ultrasound, 1200 North State Street. Los Angeles. California 80033. VOLUME 5. NUMBER 4
Pelvic Masses
denotes a combination of abrupt pain, syncope, or shock from massive hemorrhage. Kobayashi describes uterine and extrauterine findings in the classical ultrasonic presentation of ectopic pregnancy. Associated with the uterine findings are a) ,diffuse homogeneous uterine echoes, b) uterine enlargement, c) absence of an intrauterine pregnancy. Extrauterine findings are directed toward demonstration of a) an ectopic gestational sac or fetal parts, b) a cystic appearing irregular mass containing internal echoes, and c) a hernoperitoneum evidenced by a cystic mass in the cul de sac with or without an echo pattern similar to ascites. Understandably, visualization of an extrauterine fetal head is diagnostic but rarely occurs. Figure 1A shows the classical ultrasonic picture of an ectopic pregnancy with a slightly enlarged uterus with diffuse internal echoes, but without evidence of an intrauterine pregnancy. To the right of the midline (1B) a semicystic adnexal mass is evident. At surgery, an ectopic pregnancy with numerous adhesions was discovered in the right fallopian tube. There was no evidence of rupture. Culdocentesis before surgery had been negative. This patient demonstrates many of the classical ultrasonic findings of chronic ectopic pregnancy. Combining these findings with the clinical impressions and the 2 87
FIGURE 1A. Longitudinal section 2 cm to the left of midline. The uterus is slightly enlarged with diffuse homogeneous internal echoes. No fetal or gestational structures are identified within the uterus. The vertical linear shadow in the central portion of the picture i s an artifact. U = uterus, 6 = bladder, S = symphysis pubis.
FIGURE 18. Longitudinal section 4 cm to the right of midline. A 6 cm semicystic adnexal mass is identified posterior and slightly superior to the bladder. The vertical linear shadow in the central portion of the picture is an artifact. B = bladder, M =semicystic, S = symphysis pubis.
FIGURE 2A. Midline longitudinal section demonstrating a large pelvic mass with irregular, nonuniform echoes. The normal pelvic structures are obscured by the extensive necrosis and inflammatory reaction. B = bladder, S = symphysis pubis, U = umbilicus.
FIGURE 28. Transverse section through the semicystic mass.
The range markers to the right of the picture indicate 1 cm intervals. left side.
M
= midline,
R = materal right side, L = maternal
positive pregnancy test should lead to the diag- phasize the differences in ultrasonic presentanosis. One must be critical in evaluating a posi- tions. Often a pelvic mass is demonstrated that tive pregnancy test. Reportedly, pregnancy tests cannot be precisely defined but which usually are positive in approximately one-half of the incorporates the uterus. Figure 2A demonstrates patients with chronic ectopic pregnancy (3). the midline longitudinal section and a transverse Arkin (5) observed false-positive results with the section (2B)through an infected chronic ectopic latex-particle agglutination-inhibition test in pat- pregnancy. In comparison with Figure 1, the echoes within the pelvic mass are irregularly ients with tubo-ovarian acscess. Frequently, chronic ectopic pregnancies will distributed, nonuniform, and of distinctly not present in the previously described classi- different quality than the uterine echoes visuacal description. The following examples em- lized in Figure l. The extensive necrosis and 258
JOURNAL OF CLINICAL ULTRASOUND
FIGURE 3. Midline longitudinal section showing an irregular semicystic pelvic mass associted with free fluid within the cul de sac and anterior peritoneal cavity. B = bladder, U = umbilicus, S = symphysis pubis, F = free fluid.
inflammatory reaction obscure the normal anatomical structures and render their boundaries difficult to ascertain. The echo pattern from this mass is distinctly different from a hydatiform mole and should not be confused with that diagnosis. Other ultrasonic findings might be useful in aiding one to diagnose a chronic ectopic pregnancy. As previously discussed, the tendency to rupture and hemorrhage often produces irregular collections of fluid within the pelvis or abdomen. The longitudinal section in Figure 3 demonstrates an irregular mixed or semicystic pelvis mass with associated free fluid within the cul de sac and anterior peritoneal cavity. This free fluid ultimately proved to be blood associated with clots within these areas. The lack of definition of normal uterine and adnexal structures is again evident. The echo pattern within the semicystic mass posterior to the bladder is a result of extensive necrosis, hemorrhage, and inflammatory reaction. In Figure 4, three views of an ultrasound examination demonstrate how the chronicity, excessive inflammatory reaction, and tendency to rupture with hemorrhage can result in confusing images because of obliteration of normal anatomical structures. The examples illustrate the extensive involvement of pelvic structures and complexity of ultrasonic findings associated with chronic ectopic pregnancy. At surgery a normal-sized uterus was found which had massive adhesions to the anterior peritoneum, posterior bladder, large and small bowel, and both adnexal areas. There was a large volume of VOLUME 6. NUMBER 4
FIGURE 4A. A midline longitudinal sectim illustrating what appear to be an enlarged uterus with irregular internal echoes. Note the illdefined margins of the mass. No definite gestational or fetal structures are identified. B = bladder, M = mass, S = symphysis pubis, U = umbilicus.
FIGURE 46. Longitudinal section 4 cm to the right of midline demonstrating portions of the mass having solid and cystic areas within it. B = bladder, M = mass, S = symphysis pubis, U = umbilicus.
blood in the pelvis, with organized clots and fibrin involving a left adnexal mass, the uterus, and the right ovary. Upon removal and sectioning of the left adnexal mass, a gestational sac was located within, but neither ovarian nor fallopian tissue could be identified. The clinician often encounters difficulty in differentiating among various types of pelvic masses. The ultrasonic examination is useful in demonstrating the disease entity. Firgure 5 demonstrates a pelvic mass with ill-defined borders. This patient had a gestational age of 289
FIGURE 4C. Another portion of the mass is demonstrated in this section taken 3 cm to the left of midline. The lack of normal pelvic structures is evident. Again identified are the irregular echoes and cystic areas. B = bladder, M = mass, S = symphysis pubis.
FIGURE 5. This longitudinal section is 3 cm to the right of midline. The ill-defined pelvic mass has irregular echoes and might easily be confused with uterine leiomyomata. B = bladder, M = mass, S = symphysis pubis.
nine weeks but the pelvic mass was approximately that of a 16 week-sized uterus. Culdocentesis was negative, but the pregnancy test was positive. The patient was subsequently diagnosed as having a chronic ectopic pregnancy. The important differentiating points are the echo pattern which is not characteristic of a volar pregnancy but which might easily be confused with uterine leiomyomata, the lack of definition of normal uterine and pelvic structures with repeated ultrasonic scans, the positive pregnancy test, and lack of intrauterine gestational or fetal structures. Several descriptions of the classical ultrasonic presentation of chronic ectopic pregnancies have been reported by various authors ( 1 , 6-8). The ultrasonographer will frequently encounter variations of the classical presentation and will very rarely be able to identify fetal structures outside of the uterus. The ultrasonic images are a result of a combination of events and structures. The events would include ectopic implantation of the fertilized ovum, erosion, rupture with hemorrhage, inflammatory reaction, organization, and formation of adhesions. The structures would include any or all of the pelvic anatomy, hematomas, and inflammatory mass. Obliteration of normal pelvic structures, cystic areas with or without free abdominal or pelvic fluid, and an ill-defined pelvic mass with irregular echo patterns should alert theultrasonographer to consider chronic ectopic pregnancy.
Correlation with the laboratory and clinical data should assist in the correct diagnosis.
260
ACKNOWLEDGMENT
The authors sincerely appreciate the assistance of Eileen de la Vega and Marie Andrianos in producing this manuscript and the technical assistance of Marcia Fodran, Sally Smith, and Elvira Vinson. REFERENCES 1. Kobayashi M. Hellman LM, Cromb E, and Chesley LC: Ectopic Pregnancy. In Atlas of Ultrasonography in Obstetrics and Gynecology. New York, Meredith Corporation, 1972, p. 137. 2. Jarcho J: Ectopic pregnancy: With special reference to abdominal pregnancy. Am J Surg 77:273,1945. 3. Case Records of the Massachusettes General Hospital (Case 11-1976). N Engl J Med 294:600,1976. 4. Hoerner MT: Bilateral simultaneous tuba1 pregnancy: Review of literature and report of case. Am J Surg 91:358,1956. 5. Arkin C, Noto TA: A False positive immunologic pregnancy test with tubo-ovarian acscess. Am J Clin Path 58:314,1972. 6. Cochrane WJ: Ultrasound in gynecology. Radio1 Clin North Am 13:463,1975. 7. Goldberg BB, Kotler MN, Ziskin MC, and Waxham RD: Ectopic Pregnancy. In Diagnostic Uses of Ultrasound. New York, Grune and Stratton, 1975, p. 384. 8. Brown RE: Ultrasonography: Basic Principles and Clinical Applications. St. Louis, Warren H. Green, Inc., 1975.
JOURNAL O F CLINICAL ULTRASOUND
