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Distribution of intraprostatic hyperechoic lesions in infertile men
DISTRIBUTION OF INTRAPROSTATIC HYPERECHOIC LESIONS IN INFERTILE MEN RAYMOND JONATHAN
E. POORE, M.D. F! JAROW, M.D.
From the Department of Urology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina
ABSTRACT-Objectives. To determine whether intraprostatic hyperechogenic lesions seen on transrectal ultrasonography are related to infertility. Methods. The transrectal ultrasonographic studies of 58 infertile men and 12 fertile controls who all had intraprostatic hyperechoic lesions were reviewed to determine the anatomic distribution of hyperechoic lesions within the prostate and their relationship to the ejaculatory ducts. Results. Hyperechoic lesions were located in the region of the verumontanum in 62% of the fertile control subjects and only 22% of infertile patients (P < 0.05). In contrast, hyperechoic lesions were present in the region of the ejaculatory ducts in 75% of the infertile men and only 39% of the fertile controls (P c 0.05). Conclusions. Hyperechogenic lesions located within the verumontanum appear to be a normal finding in fertile men, whereas lesions located in the region of the ejaculatory ducts are more likely to be associated with infertility.
Ejaculatory duct obstruction is a rare but correctable cause of male factor infertility Complete ejaculatory duct obstruction is suspected in azoospermic and severely oligospermic patients with low ejaculate volume and can be diagnosed by vasography.1-3 In contrast, establishing the diagnosis of unilateral or partial ejaculatory duct obstruction is much more difficult. Transrectal ultrasonography (TRUS) is currently the most popular noninvasive imaging modality of the prostate and seminal vesicles and is readily available to most urologists. TRUS findings associated with infertility include dilated seminal vesicles, intraprostatic cysts, and intraprostatic hyperechoic lesions.4-11 However, none of these findings is pathognomonic for partial ejaculatory duct obstruction. If lesions seen on TRUS are found explicitly or primarily in infertile men, then their presence is associated with infertility In a recent study comparing the TRUS findings of 30 fertile volunteers to 150 men attending an infertility clinic, we found a significantly higher prevalence of mullerian duct cysts within the prostates of the Submitted: September October 11, 1994
UROLOGY@
/MARCH
2, 1994, accepted (with
1995
I VOLUME
45,
NUMBER
3
revisions):
infertile men, suggesting that these lesions are associated with infertility. However, the prevalence of intraprostatic hyperechoic lesions was the same in both groups. l2 If hyperechoic lesions of the prostate are more commonly found in the region of the ejaculatory ducts, then their presence may reflect abnormal ejaculatory duct function. The purpose of this study was to characterize further intraprostatic hyperechoic lesions seen in fertile and infertile men by determining their anatomic distribution within the prostate. MATERIAL
AND METHODS
TRUS was performed on 150 consecutive men referred to our center for evaluation of male factor infertility and on 30 fertile male volunteers. Internal review board approval was obtained. The Hitachi EUB 450 ultrasound unit with a 6.5 MHz biplanar transducer was used for all studies. Patients were placed in the lateral decubitus position for ultrasound imaging. Images were obtained in both sagittal and transverse planes. Hyperechogenicity was defined as an echo pattern significantly brighter than the surrounding prostatic parenchyma and equivalent to that seen with a calculus. Intraprostatic hyperechoic lesions were
467
TABLE I.
Distribution of hyperechoic within prostate (%).
Transverse Fertile controls Infertile patients Sagittal Fertile controls Infertile patients
T, 62* 22
T2 16 16
s, 85 87
% 46 30
lesions T3 39’ 75
T4 7 3
*P <0.05.
FIGURE 1. Schematic representation view of the prostate on transrectal The prostate was arbitrarily divided I
I
~
\
\
of a transverse ultrasonography. into four zones.
tanum (zone Tl) compared with only 22% of the infertile patients (P = 0.014). Infertile patients had a significantly higher frequency of hyperechoic lesions located within the zone containing the ejaculatory ducts (zone T3) than fertile control men (P = 0.02). The relationship of these lesions to the ejaculatory ducts could not be further characterized because of the difficulty visualizing the ejaculatory ducts. All of the other zones on both transverse and sagittal imaging had a similar frequency distribution of hyperechoic lesions between the two groups (Table I).
:.>:.:.:.::.:.:.:.: ................................... ::i:~:i:i’:~i::.......:.....:::::: .... ....... ................ v. ..::::::::::. ... ..:.:.:i.>:.:.:.: ... ............ *.:.:.:.* ... ............................... ................................. I
nl
COMMENT
I FIGURE2. Schematic representation of a sagittal of the prostate on transrectal ultrasonography. prostate was arbitrarily divided into two zones.
view The
observed in 58 infertile men (39%) and 12 fertile control men (40%). The prostate was arbitrarily divided into four zones on transverse imaging and two zones on sagittal imaging (Figs. 1 and 2). The zones were created so as to divide the prostate into areas containing the ejaculatory ducts and areas distant to the ejaculatory ducts. The frequency distribution of hyperechoic lesions for each zone within the prostate was determined retrospectively for the control and infertile groups by reviewing their TRUS studies in a blinded fashion. Fisher’s exact test was used to compare the frequency distribution between the two groups. RESULTS The mean age of the 30 fertile controls (29.5 years) was significantly lower than the 150 patients (34.6 years) (P ~0.01). Hyperechoic lesions within the prostate were observed in 39% of infertile patients and 40% of fertile controls (P ~0.05). Sixty-two percent of controls demonstrated hyperechoic lesions within the verumon-
468
This study confirms previous reports documenting a relatively high prevalence of hyperechoic lesions within the prostates of young healthy men. In a study of 2000 men, Fornage13 found “calcifications” within the prostate glands of approximately 55% of men between the ages of 30 and 40 years. In a review of transrectal ultrasonography, Carter and associates4 state that the normal verumontanum is frequently echogenic, presumably due to a buildup of prostatic concretions. However, Littrup and associates8 found a much higher prevalence of intraprostatic hyperechoic lesions of 88% in 52 symptomatic men studied with TRUS, suggesting that these lesions are pathologic. Clearly, hyperechoic lesions can be a normal or incidental finding in some patients and potentially pathologic in others. Intraprostatic hyperechoic lesions may represent corpora amylacea11,13 or possible scarring of the prostate from prior infection or an inflammatory disorder.8J l In some instances these ultrasonographic lesions may be caused by actual calcification of the wall of the ejaculatory ducts14J5 or ejaculatory duct calculi. 8~1oThe exact pathogenesis of these hyperechoic lesions is unknown and they may represent a heterogeneous group with varying etiologies and differing effects on fertility. Theoretically, some or all of these intraprostatic lesions may produce obstruction of the ejaculatory
UROLOGY@ / MARCH 1995 I VOLUME45, NUMBER3
ducts. The ejaculatory ducts arise at the base of the prostate gland and are formed by the confluence of the seminal vesicles and ampulla of the vasa. The ducts then course medially and anteriorly through prostatic parenchyma to empty into the urethra on either side of the verumontanum. Therefore, it is possible that an intraprostatic lesion located along this course or a stone within the duct itself could cause obstruction of the ejaculatory duct. Traditionally, the diagnosis of ejaculatory duct obstruction is based on the evaluation of seminal parameters, including volume, count, and fructose and is ultimately confirmed by vasographyl In patients with either unilateral, partial, or a functional obstruction of the ejaculatory ducts the diagnosis is much more difficult.14J6 Findings on TRUS may suggest the diagnosis of obstruction but neither TRUS nor vasography has been documented to be able to be used reliably to diagnose the presence of partial obstruction. We had arbitrarily divided the prostate into zones anatomically adjacent to and far away from the course of the ejaculatory ducts. The similar prevalence of these hyperechoic lesions in the fertile and infertile populations observed in our previous study” suggested that, contrary to prevailing views, intraprostatic hyperechoic lesions do not play a significant role in infertility The current study demonstrates that the anatomic distribution of these lesions within the prostate is significantly different, suggesting that the location of these lesions is more important than their mere presence. Hyperechoic lesions are more commonly seen in the verumontanum in the fertile group and are more frequently located posterior to the urethra in the region of the ejaculatory ducts in the infertile group. We conclude that hyperechoic lesions located in the verumontanum are most likely an incidental finding and probably do not represent significant pathologic changes. Lesions located in the region of the ejaculatory ducts are more frequently observed in infertile men and, therefore, are more likely to be pathologic. However, there was significant overlap between the two groups and more than one third of the fertile control men had lesions located in the region of the ejaculatory ducts. Therefore, one should be careful to avoid overinterpreting the results of
U RO LOGY@ I MARCH 1995 I VOLUME 45, NUMBER 3
TRUS, and a patient’s management should not be based solely on this single diagnostic study. Jonathan P. Jarow, M.D. Department of Urology Bowman Gray School of Medicine Wake Forest University Medical Center Boulevard Winston-Salem, NC 27157-1094 REFERENCES 1. Pryor JP, and Hendry WF: Ejaculatory duct obstruction in subfertile males: analysis of 87 patients. Fertil Steril 56: 725-730, 1991. 2. Silber SJ: Ejaculatory duct obstruction. J Urol 124: 294-297, 1980. 3. Carson CC: Transrectal resection for ejaculatory duct stenosis and oligospermia. Fertil Steril 41: 482-484, 1984. 4. Carter SC, Shinohara K, and Lipshultz Ll: Transrectal ultrasonography in disorders of the seminal vesicles and ejaculatory ducts. Urol Clin North Am 16: 773-790, 1989. 5. Shabsigh R, Lerner S, Fishman IJ, and Kadman D: The role of transrectal ultrasonography in the diagnosis and management of prostatic and seminal vesicle cysts. J Urol 141: 1206-1209, 1989. 6. Patterson L, and Jarow JP: Transrectal ultrasonography in the evaluation of the infertile man: a report of 3 cases. J Urol 144: 1469-1471, 1990. 7. Takatera H, Sugao H, and Sakurai T: Ejaculatory duct cyst: the case for effective use of transrectal longitudinal ultrasonography. J Urol 137: 1241-1242, 1987. 8. Littrup PJ, Lee F, McLeary RD, Wu D, Lee A, and Kumasaka GH: Transrectal US of the seminal vesicles and ejaculatory ducts: clinical correlation. Radiology 168: 625-628, 1988. 9. Worischeck JH, and Parra RO: Transrectal ultrasound in the evaluation of men with low volume azoospermia. J Urol 149: 1341-1344, 1993. 10. Kuligowska E, Baker CE, and Oates RD: Male infertility: role of transrectal US in diagnosis and management. Radiology 185: 353-360, 1992. 11. Fisch H: Transurethral resection of the ejaculatory ducts, Olsson CA, (Ed), in: Current Surgical Techniques in Urology, Wilmington, Medical Publications, 1992, pp 2-6. 12. Jarow JP: Transrectal ultrasonography of infertile men. Fertil Steril 60: 1035-1039, 1993. 13. Fornage BD: Normal US anatomy of the prostate. Ultrasound Med Biol 12: 1011-1021, 1986. 14. Meacham RB, Hellerstein DK, and Lipshultz LI: Evaluation and treatment of ejaculatory duct obstruction in the infertile male. Fertil Steril 59: 393-397, 1993. 15. Honig SC: Use of ultrasonography in the evaluation of the infertile man. World J Urol 11: 102-110, 1993. 16. Hellerstein DK, Meacham RB, and Lipshultz LI: Transrectal ultrasound and partial ejaculatory duct obstruction in male infertility. Urology 39: 449-452, 1992.
469
E. POORE, M.D. F! JAROW, M.D.
From the Department of Urology, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, North Carolina
ABSTRACT-Objectives. To determine whether intraprostatic hyperechogenic lesions seen on transrectal ultrasonography are related to infertility. Methods. The transrectal ultrasonographic studies of 58 infertile men and 12 fertile controls who all had intraprostatic hyperechoic lesions were reviewed to determine the anatomic distribution of hyperechoic lesions within the prostate and their relationship to the ejaculatory ducts. Results. Hyperechoic lesions were located in the region of the verumontanum in 62% of the fertile control subjects and only 22% of infertile patients (P < 0.05). In contrast, hyperechoic lesions were present in the region of the ejaculatory ducts in 75% of the infertile men and only 39% of the fertile controls (P c 0.05). Conclusions. Hyperechogenic lesions located within the verumontanum appear to be a normal finding in fertile men, whereas lesions located in the region of the ejaculatory ducts are more likely to be associated with infertility.
Ejaculatory duct obstruction is a rare but correctable cause of male factor infertility Complete ejaculatory duct obstruction is suspected in azoospermic and severely oligospermic patients with low ejaculate volume and can be diagnosed by vasography.1-3 In contrast, establishing the diagnosis of unilateral or partial ejaculatory duct obstruction is much more difficult. Transrectal ultrasonography (TRUS) is currently the most popular noninvasive imaging modality of the prostate and seminal vesicles and is readily available to most urologists. TRUS findings associated with infertility include dilated seminal vesicles, intraprostatic cysts, and intraprostatic hyperechoic lesions.4-11 However, none of these findings is pathognomonic for partial ejaculatory duct obstruction. If lesions seen on TRUS are found explicitly or primarily in infertile men, then their presence is associated with infertility In a recent study comparing the TRUS findings of 30 fertile volunteers to 150 men attending an infertility clinic, we found a significantly higher prevalence of mullerian duct cysts within the prostates of the Submitted: September October 11, 1994
UROLOGY@
/MARCH
2, 1994, accepted (with
1995
I VOLUME
45,
NUMBER
3
revisions):
infertile men, suggesting that these lesions are associated with infertility. However, the prevalence of intraprostatic hyperechoic lesions was the same in both groups. l2 If hyperechoic lesions of the prostate are more commonly found in the region of the ejaculatory ducts, then their presence may reflect abnormal ejaculatory duct function. The purpose of this study was to characterize further intraprostatic hyperechoic lesions seen in fertile and infertile men by determining their anatomic distribution within the prostate. MATERIAL
AND METHODS
TRUS was performed on 150 consecutive men referred to our center for evaluation of male factor infertility and on 30 fertile male volunteers. Internal review board approval was obtained. The Hitachi EUB 450 ultrasound unit with a 6.5 MHz biplanar transducer was used for all studies. Patients were placed in the lateral decubitus position for ultrasound imaging. Images were obtained in both sagittal and transverse planes. Hyperechogenicity was defined as an echo pattern significantly brighter than the surrounding prostatic parenchyma and equivalent to that seen with a calculus. Intraprostatic hyperechoic lesions were
467
TABLE I.
Distribution of hyperechoic within prostate (%).
Transverse Fertile controls Infertile patients Sagittal Fertile controls Infertile patients
T, 62* 22
T2 16 16
s, 85 87
% 46 30
lesions T3 39’ 75
T4 7 3
*P <0.05.
FIGURE 1. Schematic representation view of the prostate on transrectal The prostate was arbitrarily divided I
I
~
\
\
of a transverse ultrasonography. into four zones.
tanum (zone Tl) compared with only 22% of the infertile patients (P = 0.014). Infertile patients had a significantly higher frequency of hyperechoic lesions located within the zone containing the ejaculatory ducts (zone T3) than fertile control men (P = 0.02). The relationship of these lesions to the ejaculatory ducts could not be further characterized because of the difficulty visualizing the ejaculatory ducts. All of the other zones on both transverse and sagittal imaging had a similar frequency distribution of hyperechoic lesions between the two groups (Table I).
:.>:.:.:.::.:.:.:.: ................................... ::i:~:i:i’:~i::.......:.....:::::: .... ....... ................ v. ..::::::::::. ... ..:.:.:i.>:.:.:.: ... ............ *.:.:.:.* ... ............................... ................................. I
nl
COMMENT
I FIGURE2. Schematic representation of a sagittal of the prostate on transrectal ultrasonography. prostate was arbitrarily divided into two zones.
view The
observed in 58 infertile men (39%) and 12 fertile control men (40%). The prostate was arbitrarily divided into four zones on transverse imaging and two zones on sagittal imaging (Figs. 1 and 2). The zones were created so as to divide the prostate into areas containing the ejaculatory ducts and areas distant to the ejaculatory ducts. The frequency distribution of hyperechoic lesions for each zone within the prostate was determined retrospectively for the control and infertile groups by reviewing their TRUS studies in a blinded fashion. Fisher’s exact test was used to compare the frequency distribution between the two groups. RESULTS The mean age of the 30 fertile controls (29.5 years) was significantly lower than the 150 patients (34.6 years) (P ~0.01). Hyperechoic lesions within the prostate were observed in 39% of infertile patients and 40% of fertile controls (P ~0.05). Sixty-two percent of controls demonstrated hyperechoic lesions within the verumon-
468
This study confirms previous reports documenting a relatively high prevalence of hyperechoic lesions within the prostates of young healthy men. In a study of 2000 men, Fornage13 found “calcifications” within the prostate glands of approximately 55% of men between the ages of 30 and 40 years. In a review of transrectal ultrasonography, Carter and associates4 state that the normal verumontanum is frequently echogenic, presumably due to a buildup of prostatic concretions. However, Littrup and associates8 found a much higher prevalence of intraprostatic hyperechoic lesions of 88% in 52 symptomatic men studied with TRUS, suggesting that these lesions are pathologic. Clearly, hyperechoic lesions can be a normal or incidental finding in some patients and potentially pathologic in others. Intraprostatic hyperechoic lesions may represent corpora amylacea11,13 or possible scarring of the prostate from prior infection or an inflammatory disorder.8J l In some instances these ultrasonographic lesions may be caused by actual calcification of the wall of the ejaculatory ducts14J5 or ejaculatory duct calculi. 8~1oThe exact pathogenesis of these hyperechoic lesions is unknown and they may represent a heterogeneous group with varying etiologies and differing effects on fertility. Theoretically, some or all of these intraprostatic lesions may produce obstruction of the ejaculatory
UROLOGY@ / MARCH 1995 I VOLUME45, NUMBER3
ducts. The ejaculatory ducts arise at the base of the prostate gland and are formed by the confluence of the seminal vesicles and ampulla of the vasa. The ducts then course medially and anteriorly through prostatic parenchyma to empty into the urethra on either side of the verumontanum. Therefore, it is possible that an intraprostatic lesion located along this course or a stone within the duct itself could cause obstruction of the ejaculatory duct. Traditionally, the diagnosis of ejaculatory duct obstruction is based on the evaluation of seminal parameters, including volume, count, and fructose and is ultimately confirmed by vasographyl In patients with either unilateral, partial, or a functional obstruction of the ejaculatory ducts the diagnosis is much more difficult.14J6 Findings on TRUS may suggest the diagnosis of obstruction but neither TRUS nor vasography has been documented to be able to be used reliably to diagnose the presence of partial obstruction. We had arbitrarily divided the prostate into zones anatomically adjacent to and far away from the course of the ejaculatory ducts. The similar prevalence of these hyperechoic lesions in the fertile and infertile populations observed in our previous study” suggested that, contrary to prevailing views, intraprostatic hyperechoic lesions do not play a significant role in infertility The current study demonstrates that the anatomic distribution of these lesions within the prostate is significantly different, suggesting that the location of these lesions is more important than their mere presence. Hyperechoic lesions are more commonly seen in the verumontanum in the fertile group and are more frequently located posterior to the urethra in the region of the ejaculatory ducts in the infertile group. We conclude that hyperechoic lesions located in the verumontanum are most likely an incidental finding and probably do not represent significant pathologic changes. Lesions located in the region of the ejaculatory ducts are more frequently observed in infertile men and, therefore, are more likely to be pathologic. However, there was significant overlap between the two groups and more than one third of the fertile control men had lesions located in the region of the ejaculatory ducts. Therefore, one should be careful to avoid overinterpreting the results of
U RO LOGY@ I MARCH 1995 I VOLUME 45, NUMBER 3
TRUS, and a patient’s management should not be based solely on this single diagnostic study. Jonathan P. Jarow, M.D. Department of Urology Bowman Gray School of Medicine Wake Forest University Medical Center Boulevard Winston-Salem, NC 27157-1094 REFERENCES 1. Pryor JP, and Hendry WF: Ejaculatory duct obstruction in subfertile males: analysis of 87 patients. Fertil Steril 56: 725-730, 1991. 2. Silber SJ: Ejaculatory duct obstruction. J Urol 124: 294-297, 1980. 3. Carson CC: Transrectal resection for ejaculatory duct stenosis and oligospermia. Fertil Steril 41: 482-484, 1984. 4. Carter SC, Shinohara K, and Lipshultz Ll: Transrectal ultrasonography in disorders of the seminal vesicles and ejaculatory ducts. Urol Clin North Am 16: 773-790, 1989. 5. Shabsigh R, Lerner S, Fishman IJ, and Kadman D: The role of transrectal ultrasonography in the diagnosis and management of prostatic and seminal vesicle cysts. J Urol 141: 1206-1209, 1989. 6. Patterson L, and Jarow JP: Transrectal ultrasonography in the evaluation of the infertile man: a report of 3 cases. J Urol 144: 1469-1471, 1990. 7. Takatera H, Sugao H, and Sakurai T: Ejaculatory duct cyst: the case for effective use of transrectal longitudinal ultrasonography. J Urol 137: 1241-1242, 1987. 8. Littrup PJ, Lee F, McLeary RD, Wu D, Lee A, and Kumasaka GH: Transrectal US of the seminal vesicles and ejaculatory ducts: clinical correlation. Radiology 168: 625-628, 1988. 9. Worischeck JH, and Parra RO: Transrectal ultrasound in the evaluation of men with low volume azoospermia. J Urol 149: 1341-1344, 1993. 10. Kuligowska E, Baker CE, and Oates RD: Male infertility: role of transrectal US in diagnosis and management. Radiology 185: 353-360, 1992. 11. Fisch H: Transurethral resection of the ejaculatory ducts, Olsson CA, (Ed), in: Current Surgical Techniques in Urology, Wilmington, Medical Publications, 1992, pp 2-6. 12. Jarow JP: Transrectal ultrasonography of infertile men. Fertil Steril 60: 1035-1039, 1993. 13. Fornage BD: Normal US anatomy of the prostate. Ultrasound Med Biol 12: 1011-1021, 1986. 14. Meacham RB, Hellerstein DK, and Lipshultz LI: Evaluation and treatment of ejaculatory duct obstruction in the infertile male. Fertil Steril 59: 393-397, 1993. 15. Honig SC: Use of ultrasonography in the evaluation of the infertile man. World J Urol 11: 102-110, 1993. 16. Hellerstein DK, Meacham RB, and Lipshultz LI: Transrectal ultrasound and partial ejaculatory duct obstruction in male infertility. Urology 39: 449-452, 1992.
469