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Low resistance Doppler waveforms with retained products of conception: potential for diagnostic confusion with gestational trophoblastic disease
EUROPEAN JOURNAL OF RADIOLOGY
ELSEVIER
European Journal of Radiology21 (1995) 109-1i !
Low resistance Doppler waveforms with retained products of conception: potential for diagnostic confusion with gestational trophoblastic disease M a r y T, K e o g a n * , B a r b a r a S. H e r t z b e r g , M a r k A. K l i e w e r Duke University Medical Center, Department of Radiology, Box 3808, Durham, N. C 27710, USA
Received29 August 1995;accepted 3 October 1995
Keywords: Ultrasound (US); Doppler studies; Ultrasound (US), uterus; Pregnancy, ultrasound studies
1. Introduction Doppler interrogation of masses in the gravid uterus has been recently promoted as a useful adjunct to gray scale ultrasound (US) imaging for the diagnosis of gestational trophoblastic disease. The impetus for these efforts derives partly from the unfortunate fact that potentially competing diagnoses - - such as incomplete abortion with degenerating retained products of conception or hydropic degeneration of the placenta - - may appear remarkably similar to gestational trophoblastic disease by gray scale ultrasound imaging alone [1,2]. While correlation of the gray scale ultrasound appearance with high levels of ~hCG raises the likelihood that ultrasound findings are due to gestational trophoblastic disease, a quantitative/3hCG level is not always available at the time of the sonographic interpretation, and occasionally low/3hCG levels are found in patients with persistent gestational trophoblastic neoplasia [2,3]. Recently, investigators have described a low impedance Doppler signal in cases of trophoblastic disease and have suggested that this Doppler signal is characteristic of trophoblastic disease [3,4]. We describe a case in which both gray scale and Doppler findings reproduced those previously described as representative of trophoblastic disease, but were eventually found to derive from degenerating retained products of conception without gestational trophoblastic disease. We conclude that even in the setting of a positive ~hCG and gray scale ultrasound findings typical of * Correspondingauthor, Tel.: +! 919 687830;Fax: +! 919 6847138.
gestational trophoblastic neoplasia, very low impedance Doppler signals are not specific for gestational trophoblastic disease. 2. Case report A 16-year old black female presented to the emergency room with vaginal bleeding and cramping lower abdominal pain. At presentation the patient was 9 weeks post-therapeutic abortion and had since engaged in unprotected intercourse. She had not yet had a normal menstrual cycle, and had no recollection of passing tissue vaginally. On physical examination, the size of the uterus was compatible with a 6-week pregnancy, the cervical ostium was closed, and there was no blood in the vaginal vault. The clinical impression at this time favored early intrauterine pregnancy, though retained products of conception from the recently terminated pregnancy was also considered. The patient was discharged from the emergency room with a scheduled return in 48 h. The patient presented a second time to the emergency room 2 days later complaining of increased pain and vaginal bleeding. A urine pregnancy test was positive but a quantitative ~hCG level was not available. Transabdominal and endovaginal ultrasound revealed an enlarged uterus containing an intrauterine mass with multiple cystic spaces which expanded the uterine cavity (Fig. 1). There was no evidence of an intrauterine pregnancy. Color Doppler imaging demonstrated abundant blood flow in the mass. Spectral Doppler tracings of this flow revealed a remarkably high diastolic component relative to systole, producing a calculated resistivity index
0720-048X/95/$09.50 © 1995ElsevierScienceIreland Ltd. All rights reserved SSDI 0720-1M8X(95)00709-Y
110
M.T. Keogan et al. / European Journal of Radiology 21 (1995) 109-111
Fig. I. Endovaginal coromd sonogram. Enlarged uterus containing a mass with cystic spaces (aITow).
value of 0.27 (Fig. 2). Both ovaries were sonographically normal and no adnexal masses were seen. The combination of the gray scale ultrasound and Doppler findings were considered characteristic of molar pregnancy. Pelvic examination 'under anesthesia revealed a "boggy" uterus 6 weeks in :size. Dilatation and curettage was performed and pathologic examination of the uterine contents revealed nec:rotic and degenerating chorionic villi and decidua. There was no evidence of trophoblastic proliferation. The final pathologic diagnosis was retained products of conception with hydropic degeneration of the placenta. Following this procedure, the BhCG level dropped from an initial level of 26-500 IU/I to 10.9 IU/L. The patient has remained well on followup at 16 weeks. 3. Discussion
The most characteristic B-mode sonographic appearance of a hydatidiform mole is a large echogenic
Fig. 2. Pulsed Doppler tracing of the uterine contents demonstrating relatively high diastolic flow.
soft tissue mass filling the uterine cavity and containing small cystic spaces [2]. In the first trimester, the hydropic vesicles may be too small to be resolved and the sonographic appearance can be variable and nonspecific [I]. As a result, first trimester molar pregnancies are sometimes misdiagnosed as missed abortion or hydropic degeneration of the placenta [3]. Hydropic degeneration of the placenta is not part of the spectrum of trophoblastic disease, and is characterized pathologically by a variable degree of vesicular change, hemorrhage, necrosis, and breakdown of the products of conception. Although the quantitative level of serum BhCG is frequently crucial in distinguishing between gestational trophoblastic neoplasia and hydropic degeneration of the placenta, a quantitative level may not be available at the time the sonograms are interpreted, and occasionally this level will be relatively low in patients with persistent gestational trophoblastic neoplasia [3]. The Doppler signal from trophoblastic tissue has been recently characterized as having high systolic and diastolic frequencies. Moreover, investigators have claimed that this signal can distinguish between gestational trophobiastic disease and other sources of positive/~hCG such as incomplete abortion [3,4]. The low impedance, high flow state seen with gestational trophoblastic neoplasia is thought to result from enlarged spiral arteries feeding vesicular spaces and from prominent arteriovenous shunting [5]. In addition to distinguishing between degenerating retained products of conception and gestational trophoblastic disease, color and spectral Doppler features of trophoblastic tissue have been applied to the evaluation of persistent trophoblastic neoplasia [7,8], the assessment of gestational trophoblastic tumors before cytotoxic therapy [9], and the monitoring of response to chemotherapy [10]. Considering the potential confusion between the gray scale ultrasound appearance of gestational trophoblastic neoplasia and retained products of conception with hydropic degeneration of the placenta, it could be valuable and decisive if the identification of different blood flow states with the Doppler technique could distinguish among those disorders. Our case of degenerating retained products of conception, however, had both gray scale and Doppler findings that suggested the presence of a molar pregnancy. The abundant color signal and the low impedance pulsed Doppler waveforms obtained from the uterine contents simulated the Doppler features of trophoblastic tissue that have been previously reported [3,4]. This case illustrates that even in the patient with a heterogeneous intrauterine mass suggesting gestational trophoblastic disease by gray scale ultrasound, these Doppler features are not unique to trophoblastic neoplasia but can also be seen with degenerating retained products of conception.
M. T. Keogan et al. /European 3ournal of Radiology 21 (1995) 109-111
References [1] Woodward RM, Filly RA, Callen PW. First trimester molar pregnancy: non-specific uitrasonographic appearance. Obstet Gynecol 1980; 55: 33l-3S. [2] Cailen PW. Ultrasound evaluation of gestational trophoblastic neoplasia. In: Callen PW, ed. Ultrasonography in Obstetrics and Gynecology. Philadelphia: W.B. Saunders Co., 1994; 615-24. [3] Taylor KJW, Schwartz PE, Kohorn El. C-estational trophoblastic neoplasia: diagnosis with Doppler US. Radiology 1987; 165: 445-8.
[4] Desai RK, Desberg AL. Diagnosis of gestational trophoblastic disease: value of endovaginal color flow Doppler sonography. AJR 1991; 157: 787-8. [5} Fine C, Bundy AL, Berkowitz RS, Boswell SB, Berezin AF, Doubilet PM. Sonographic diagnosis of partial hydatidiform mole. Obstet Gynecol 1989; 73: 414-8.
ill
[6] Shimamoto KS, Sakuma S, Ishigaki T, Makino N. lntratumoral flood flow: evaluation with color Doppler echography. Radiology 1987; 165: 683-5. [7] Aoki S, Hata T, Hata K et al. Doppler color flow mapping of an invasive mole. Gynecol Obstet Invest 1989; 27: 52-4. [8] Dobkin GR, Berkowitz RS, Goldstein DP, Bernstein MR, Doubilet PM. Duplex ultrasonography for persistent gestational trophoblastic tumor. J Reprod Med 1991; 36: 14-6. [9] Long MG, Boultbee JE, Begent RHJ, Bagshawe KD. Preliminary Doppler studies on the uterine artery and myometrium in trophoblastic tumors requiring chemotherapy. Br J Obstet Gynecol 1990; 97: 686-9. [10] Long MG, Boultbee JE, Newlands ES, Begent RHJ~ Bagshawe KD. Doppler assessment of the uterine circulation and the clinical behaviour of gestational trophoblastic tumors requiring chemotherapy. Br J Cancer 1992; 66: 883-7.
ELSEVIER
European Journal of Radiology21 (1995) 109-1i !
Low resistance Doppler waveforms with retained products of conception: potential for diagnostic confusion with gestational trophoblastic disease M a r y T, K e o g a n * , B a r b a r a S. H e r t z b e r g , M a r k A. K l i e w e r Duke University Medical Center, Department of Radiology, Box 3808, Durham, N. C 27710, USA
Received29 August 1995;accepted 3 October 1995
Keywords: Ultrasound (US); Doppler studies; Ultrasound (US), uterus; Pregnancy, ultrasound studies
1. Introduction Doppler interrogation of masses in the gravid uterus has been recently promoted as a useful adjunct to gray scale ultrasound (US) imaging for the diagnosis of gestational trophoblastic disease. The impetus for these efforts derives partly from the unfortunate fact that potentially competing diagnoses - - such as incomplete abortion with degenerating retained products of conception or hydropic degeneration of the placenta - - may appear remarkably similar to gestational trophoblastic disease by gray scale ultrasound imaging alone [1,2]. While correlation of the gray scale ultrasound appearance with high levels of ~hCG raises the likelihood that ultrasound findings are due to gestational trophoblastic disease, a quantitative/3hCG level is not always available at the time of the sonographic interpretation, and occasionally low/3hCG levels are found in patients with persistent gestational trophoblastic neoplasia [2,3]. Recently, investigators have described a low impedance Doppler signal in cases of trophoblastic disease and have suggested that this Doppler signal is characteristic of trophoblastic disease [3,4]. We describe a case in which both gray scale and Doppler findings reproduced those previously described as representative of trophoblastic disease, but were eventually found to derive from degenerating retained products of conception without gestational trophoblastic disease. We conclude that even in the setting of a positive ~hCG and gray scale ultrasound findings typical of * Correspondingauthor, Tel.: +! 919 687830;Fax: +! 919 6847138.
gestational trophoblastic neoplasia, very low impedance Doppler signals are not specific for gestational trophoblastic disease. 2. Case report A 16-year old black female presented to the emergency room with vaginal bleeding and cramping lower abdominal pain. At presentation the patient was 9 weeks post-therapeutic abortion and had since engaged in unprotected intercourse. She had not yet had a normal menstrual cycle, and had no recollection of passing tissue vaginally. On physical examination, the size of the uterus was compatible with a 6-week pregnancy, the cervical ostium was closed, and there was no blood in the vaginal vault. The clinical impression at this time favored early intrauterine pregnancy, though retained products of conception from the recently terminated pregnancy was also considered. The patient was discharged from the emergency room with a scheduled return in 48 h. The patient presented a second time to the emergency room 2 days later complaining of increased pain and vaginal bleeding. A urine pregnancy test was positive but a quantitative ~hCG level was not available. Transabdominal and endovaginal ultrasound revealed an enlarged uterus containing an intrauterine mass with multiple cystic spaces which expanded the uterine cavity (Fig. 1). There was no evidence of an intrauterine pregnancy. Color Doppler imaging demonstrated abundant blood flow in the mass. Spectral Doppler tracings of this flow revealed a remarkably high diastolic component relative to systole, producing a calculated resistivity index
0720-048X/95/$09.50 © 1995ElsevierScienceIreland Ltd. All rights reserved SSDI 0720-1M8X(95)00709-Y
110
M.T. Keogan et al. / European Journal of Radiology 21 (1995) 109-111
Fig. I. Endovaginal coromd sonogram. Enlarged uterus containing a mass with cystic spaces (aITow).
value of 0.27 (Fig. 2). Both ovaries were sonographically normal and no adnexal masses were seen. The combination of the gray scale ultrasound and Doppler findings were considered characteristic of molar pregnancy. Pelvic examination 'under anesthesia revealed a "boggy" uterus 6 weeks in :size. Dilatation and curettage was performed and pathologic examination of the uterine contents revealed nec:rotic and degenerating chorionic villi and decidua. There was no evidence of trophoblastic proliferation. The final pathologic diagnosis was retained products of conception with hydropic degeneration of the placenta. Following this procedure, the BhCG level dropped from an initial level of 26-500 IU/I to 10.9 IU/L. The patient has remained well on followup at 16 weeks. 3. Discussion
The most characteristic B-mode sonographic appearance of a hydatidiform mole is a large echogenic
Fig. 2. Pulsed Doppler tracing of the uterine contents demonstrating relatively high diastolic flow.
soft tissue mass filling the uterine cavity and containing small cystic spaces [2]. In the first trimester, the hydropic vesicles may be too small to be resolved and the sonographic appearance can be variable and nonspecific [I]. As a result, first trimester molar pregnancies are sometimes misdiagnosed as missed abortion or hydropic degeneration of the placenta [3]. Hydropic degeneration of the placenta is not part of the spectrum of trophoblastic disease, and is characterized pathologically by a variable degree of vesicular change, hemorrhage, necrosis, and breakdown of the products of conception. Although the quantitative level of serum BhCG is frequently crucial in distinguishing between gestational trophoblastic neoplasia and hydropic degeneration of the placenta, a quantitative level may not be available at the time the sonograms are interpreted, and occasionally this level will be relatively low in patients with persistent gestational trophoblastic neoplasia [3]. The Doppler signal from trophoblastic tissue has been recently characterized as having high systolic and diastolic frequencies. Moreover, investigators have claimed that this signal can distinguish between gestational trophobiastic disease and other sources of positive/~hCG such as incomplete abortion [3,4]. The low impedance, high flow state seen with gestational trophoblastic neoplasia is thought to result from enlarged spiral arteries feeding vesicular spaces and from prominent arteriovenous shunting [5]. In addition to distinguishing between degenerating retained products of conception and gestational trophoblastic disease, color and spectral Doppler features of trophoblastic tissue have been applied to the evaluation of persistent trophoblastic neoplasia [7,8], the assessment of gestational trophoblastic tumors before cytotoxic therapy [9], and the monitoring of response to chemotherapy [10]. Considering the potential confusion between the gray scale ultrasound appearance of gestational trophoblastic neoplasia and retained products of conception with hydropic degeneration of the placenta, it could be valuable and decisive if the identification of different blood flow states with the Doppler technique could distinguish among those disorders. Our case of degenerating retained products of conception, however, had both gray scale and Doppler findings that suggested the presence of a molar pregnancy. The abundant color signal and the low impedance pulsed Doppler waveforms obtained from the uterine contents simulated the Doppler features of trophoblastic tissue that have been previously reported [3,4]. This case illustrates that even in the patient with a heterogeneous intrauterine mass suggesting gestational trophoblastic disease by gray scale ultrasound, these Doppler features are not unique to trophoblastic neoplasia but can also be seen with degenerating retained products of conception.
M. T. Keogan et al. /European 3ournal of Radiology 21 (1995) 109-111
References [1] Woodward RM, Filly RA, Callen PW. First trimester molar pregnancy: non-specific uitrasonographic appearance. Obstet Gynecol 1980; 55: 33l-3S. [2] Cailen PW. Ultrasound evaluation of gestational trophoblastic neoplasia. In: Callen PW, ed. Ultrasonography in Obstetrics and Gynecology. Philadelphia: W.B. Saunders Co., 1994; 615-24. [3] Taylor KJW, Schwartz PE, Kohorn El. C-estational trophoblastic neoplasia: diagnosis with Doppler US. Radiology 1987; 165: 445-8.
[4] Desai RK, Desberg AL. Diagnosis of gestational trophoblastic disease: value of endovaginal color flow Doppler sonography. AJR 1991; 157: 787-8. [5} Fine C, Bundy AL, Berkowitz RS, Boswell SB, Berezin AF, Doubilet PM. Sonographic diagnosis of partial hydatidiform mole. Obstet Gynecol 1989; 73: 414-8.
ill
[6] Shimamoto KS, Sakuma S, Ishigaki T, Makino N. lntratumoral flood flow: evaluation with color Doppler echography. Radiology 1987; 165: 683-5. [7] Aoki S, Hata T, Hata K et al. Doppler color flow mapping of an invasive mole. Gynecol Obstet Invest 1989; 27: 52-4. [8] Dobkin GR, Berkowitz RS, Goldstein DP, Bernstein MR, Doubilet PM. Duplex ultrasonography for persistent gestational trophoblastic tumor. J Reprod Med 1991; 36: 14-6. [9] Long MG, Boultbee JE, Begent RHJ, Bagshawe KD. Preliminary Doppler studies on the uterine artery and myometrium in trophoblastic tumors requiring chemotherapy. Br J Obstet Gynecol 1990; 97: 686-9. [10] Long MG, Boultbee JE, Newlands ES, Begent RHJ~ Bagshawe KD. Doppler assessment of the uterine circulation and the clinical behaviour of gestational trophoblastic tumors requiring chemotherapy. Br J Cancer 1992; 66: 883-7.