rora et al. CT and MRI of Seminal Vesicles Genitourinary Imaging Pictorial Essay Downloaded from www.ajronline.org by 37.44.195.159 on 12/16/17 from IP address 37.44.195.159. Copyright RRS. For personal use only; all rights reserved Sandeep S. rora 1 Richard S. reiman Emily M. Webb ntonio C. Westphalen enjamin M. Yeh Fergus V. Coakley rora SS, reiman RS, Webb EM, Westphalen C, Yeh M, Coakley FV Keywords: congenital anomalies, CT, genitourinary tract imaging, MRI, reproductive organ imaging, seminal vesicles, urinary tract DOI:10.2214/JR.06.1345 Received October 10, 2006; accepted after revision February 5, 2007. 1 ll authors: Department of Radiology, University of California, San Francisco, 505 Parnassus ve., Rm. M-372, ox 0628, San Francisco, C 94143-0628. ddress correspondence to F. V. Coakley (fergus.coakley@radiology.ucsf.edu). JR 2007; 189:130 135 0361 803X/07/1891 130 merican Roentgen Ray Society CT and MRI of Congenital nomalies of the Seminal Vesicles OJECTIVE. The purpose of this article is to provide a current review of the spectrum of CT and MRI findings seen in common congenital anomalies of the seminal vesicles. CONCLUSION. CT and MRI can both accurately show renal and seminal vesicle anomalies. Seminal vesicle anomalies often occur concurrently with renal and vasal defects. MRI is a better tool for accurately defining anatomic relationships when one is planning to excise a seminal vesicle cyst or if one is considering a difficult differential diagnosis. ongenital anomalies of the seminal C vesicles can be categorized into abnormalities of number (agenesis, fusion, duplication), maturation (hypoplastic), position (ectopia), and structure (diverticulum, cyst, communication with the ureter) [1]. In practice, agenesis and cystic anomalies are the most commonly encountered abnormalities. Upper urinary tract anomalies often coexist because of the close embryologic association of the male reproductive and urinary systems. lthough congenital anomalies of the seminal vesicles are rare, they are likely to be increasingly encountered because of the continued growth in the use of pelvic CT and MRI. The diagnosis of seminal vesicle anomalies is often delayed or missed as a result of both the rarity of these disorders and the wide spectrum of potentially confusing imaging findings they can produce. This article provides a current review of the spectrum of CT and MRI findings seen with common congenital anomalies of the seminal vesicles. genesis of the Seminal Vesicle Seminal vesicle agenesis does not occur as an isolated phenomenon (Fig. 1). It can be seen in two subsets of patients. In the first subset, an insult of unknown nature or genetic basis occurs to the mesonephric duct during embryogenesis. There is generally associated ipsilateral or bilateral agenesis or ectopia of the vas deferens [2 5]. If the insult occurs before 7 weeks of gestation (i.e., before ureteral budding), patients will have associated ipsilateral renal agenesis [2] (Fig. 1). In the second subset, bilateral or unilateral seminal vesicle agenesis is associated with corresponding agenesis of the vas deferens, the kidneys are normal, and there is an underlying mutation in the cystic fibrosis transmembrane conductance regulator gene CFTR. These patients are considered to have a primary genital form of cystic fibrosis [3, 6]. The agenesis is likely due to luminal blockade of the vas deferens and seminal vesicles by thick secretions; it probably occurs after 7 weeks of gestation. The major symptom associated with these conditions is infertility, although testicular spermatogenesis is intact. In a small fraction of patients, the ectopic vas deferens may insert into a müllerian duct remnant, which becomes dilated. Such cysts may cause symptoms such as hemospermia, epididymitis, perineal pain, and urinary tract infections. Congenital agenesis of the seminal vesicle is not surgically correctable and requires no treatment in the subgroup of unilateral seminal vesicle agenesis with a patent contralateral ductal system. In symptomatic patients, surgical options include vasoepididymostomy, transurethral resection of the ejaculatory duct, and microscopic epididymal, testicular, or vasal sperm aspiration [4]. Congenital Cystic nomalies of the Seminal Vesicle Congenital cysts of the seminal vesicle can be subcategorized as isolated cysts, cysts associated with upper urinary tract anomalies, and cysts associated with autosomal dominant polycystic kidney disease. Cysts of the seminal vesicle usually become apparent dur- 130 JR:189, July 2007
CT and MRI of Seminal Vesicles Downloaded from www.ajronline.org by 37.44.195.159 on 12/16/17 from IP address 37.44.195.159. Copyright RRS. For personal use only; all rights reserved ing the second to third decade of life, perhaps related to the onset of sexual activity at this age [7]. Cysts are mostly smaller than 5 cm in diameter and are often discovered incidentally, but they may present with a wide variety of symptoms such as hematuria, hemospermia, epididymitis, prostatitis, infertility, and urinary tract infections [7 10]. Giant cysts may present with bowel or bladder obstruction [8]. Symptomatic cysts can be excised. Sometimes elective excision is performed when cysts are detected prenatally or at an early age to prevent future complications. seminal vesicle cyst can be seen on CT as a well-defined retrovesicular mass of water or near-water attenuation that arises from the seminal vesicle cephalic to the prostate gland [11] (Fig. 2). Reported findings have been variable, ranging from a cystic pelvic mass with a thick irregular wall to apparent enlargement of the ipsilateral seminal vesicle [9]. On MRI, seminal vesicle cysts are of variable signal intensity on T1-weighted images, are generally of fluid signal intensity on T2- weighted images, and are nonenhancing after IV gadolinium administration (Figs. 2 2D). Increased T1-weighted intensity is thought to reflect hemorrhage or an increased concentration of proteinaceous fluid [11]. Cysts of the seminal vesicle are associated with ipsilateral renal agenesis or dysplasia in two thirds of patients, presumably reflecting maldevelopment of the distal mesonephric duct and faulty ureteral budding (leading to renal agenesis or dysplasia) and atresia of the ejaculatory duct (leading to obstruction and cystic dilatation of the seminal vesicle) [10, 11]. In a sonographic screening study of the kidneys in 280,000 children in Taipei, the frequency of presumed seminal vesicle cysts with ipsilateral renal agenesis or dysplasia was 0.0046% [12]. ilateral congenital cysts can be seen in patients with autosomal dominant polycystic kidney disease (Fig. 3). Cystic dilatation of the seminal vesicle may also occur along with ectopic ureteral insertion into the seminal vesicle, presumably due to ureteral budding occurring from the portion of the mesonephric duct destined to be the seminal vesicle [11] (Figs. 4 6). The ipsilateral kidney is frequently maldeveloped as well. oth CT and MRI can show the urinary tract anomalies well, but sometimes CT cannot show the opening of the ectopic ureter. MRI is better for showing the connection between the ectopic ureter and the seminal vesicles. Differential Diagnosis for Seminal Vesicle Cysts Congenital cysts and cystic dilatation of the seminal vesicles can be mimicked by several cysts and fluid-filled structures arising in neighboring organs. These include true cysts of the prostate gland, ejaculatory duct cysts, müllerian duct cysts, prostatic utricle cysts, hydronephrotic pelvic kidneys, bladder diverticula, and ureteroceles. It is important to be aware of and consider these differential diagnoses when assessing a possible seminal vesicle cyst. Differentiating features may include position (median, paramedian, or lateral), content, associations (renal agenesis or anomalies of the external genitalia), and imaging characteristics. Examples are shown in Figures 7 10. Conclusion CT and MRI can both accurately show renal and seminal vesicle anomalies. Seminal vesicle anomalies often occur concurrently with defects of the kidney and vas deferens. MRI is a better tool for accurately defining anatomic relationships when one is planning to excise a seminal vesicle cyst or if one is considering a difficult differential diagnosis because of its multiplanar imaging capability, superior soft-tissue contrast, and lack of ionizing radiation. MRI may also help depict the opening of the associated ectopic ureter. Seminal vesicle agenesis is always associated with anomalies of the vas deferens. Ectopia of vas deferens can be confirmed only by invasive vasography [4]. Diagnostic imaging is usually not necessary for determining the absence of a vas deferens because a clinician can make the diagnosis by palpation, although absence can be confirmed by thinslice CT or MRI. References 1. Nino-Murcia M, Friedland GW, devries P. Congenital anomalies of the male genitalia. In: Pollack HM, McClennan L, eds. Clinical urology, vol. 1, 2nd ed. Philadelphia, P: Saunders, 2002:868 891 2. Sandlow JI, Williams RD. Surgery of the seminal vesicles. In: Campbell s urology, vol. 4, 8th ed. Philadelphia, P: Saunders, 2002:3869 3885 3. McCallum TJ, Milunsky JM, Munarriz R, Carson R, Sadeghi-Nejad H, Oates RD. Unilateral renal agenesis associated with congenital bilateral absence of the vas deferens: phenotypic findings and genetic considerations. Hum Reprod 2001; 16:282 288 4. Wu HF, Qiao D, Qian LX, et al. Congenital agenesis of seminal vesicle. sian J ndrol 2005; 7:449 452 5. Gibbons MD, Cromie WJ, Duckett JW Jr. Ectopic vas deferens. J Urol 1978; 120:597 604 6. Dohle GR, Veeze HJ, Overbeek SE, et al. The complex relationships between cystic fibrosis and congenital bilateral absence of the vas deferens: clinical, electrophysiological and genetic data. Hum Reprod 1999; 14:371 374 7. Rappe JM, Meuleman EJH, Debruyne FMJ. Seminal vesicle cyst with ipsilateral renal agenesis. Urol Int 1993; 50:54 56 8. Heaney J, Pfister RC, Meares EM Jr. Giant cyst of the seminal vesicle with renal agenesis. JR 1987; 149:139 140 9. Kenney PJ, Leeson MD. Congenital anomalies of the seminal vesicles: spectrum of computed tomographic findings. Radiology 1983; 149:247 251 10. eeby DI. Seminal vesicle cyst associated with ipsilateral renal agenesis: case report and review of literature. J Urol 1974; 112:120 122 11. Livingston L, Larsen CR. Seminal vesicle cyst with ipsilateral renal agenesis. JR 2000; 175:177 180 12. Sheih C-P, Hung C-S, Wei C-F, Lin C-Y. Cystic dilatations within the pelvis in patients with ipsilateral renal agenesis or dysplasia. J Urol 1990; 144:324 327 JR:189, July 2007 131
rora et al. Downloaded from www.ajronline.org by 37.44.195.159 on 12/16/17 from IP address 37.44.195.159. Copyright RRS. For personal use only; all rights reserved C D Fig. 1 32-year-old man with symptoms of appendicitis., xial contrast-enhanced CT scan through pelvis shows absence of left seminal vesicle as incidental finding. Normal right seminal vesicle (arrow) is visible., Coronal reformation shows associated ipsilateral agenesis of left kidney. Normal right kidney is visible. gain note absence of left seminal vesicle, but normal right seminal vesicle (arrow) is seen. Fig. 2 31-year-old man with hematuria., xial unenhanced CT scan shows large seminal vesicle cyst (arrow) to be well-defined lowattenuation mass posterior to bladder and arising from seminal vesicle., xial T1-weighted MR image with fat saturation shows left seminal vesicle cyst (arrow) of high T1 signal intensity, presumably due to proteinaceous or hemorrhagic content. C, xial T2-weighted MR image shows cyst (arrow) has signal intensity near that of fluid. D, xial T1-weighted MR image after IV gadolinium administration shows that cyst (arrow) does not enhance. 132 JR:189, July 2007
CT and MRI of Seminal Vesicles Downloaded from www.ajronline.org by 37.44.195.159 on 12/16/17 from IP address 37.44.195.159. Copyright RRS. For personal use only; all rights reserved Fig. 3 34-year-old man with known autosomal dominant polycystic kidney disease, infertility, and recurrent epididymitis., In axial unenhanced CT scan, bilateral seminal vesicle cysts (arrows) are visible as multilobular, wellcircumscribed, low-attenuation structures., Coronal reformatted image shows typical appearance of autosomal dominant polycystic kidney disease involving both kidneys (arrows). Fig. 4 Male fetus at 30 weeks of gestation. MRI was performed for further evaluation of abnormal prenatal sonography., Sagittal T2-weighted single-shot fast spin-echo MR image (TR/TE, infinite/96) shows two cystic, fluid-filled masses in fetal pelvis. t postnatal surgery, anterior mass (white arrow) was found to be bladder, and posterior mass (black arrow) was dilated distal ureter inserting into dilated seminal vesicle., Coronal T2-weighted MR image shows ipsilateral multicystic dysplastic kidney (arrow) adjacent to dilated ureter and seminal vesicle (asterisk). Fig. 5 22-year-old man with chronic pelvic pain., xial T2-weighted MR image shows dilatation of right seminal vesicle (arrow). Fluid level is also present, presumably reflecting proteinaceous content or prior hemorrhage., Coronal T2-weighted MRI image shows that cystic dilatation is due to communication with markedly atrophic and hydronephrotic pelvic right kidney (arrow). JR:189, July 2007 133
rora et al. Downloaded from www.ajronline.org by 37.44.195.159 on 12/16/17 from IP address 37.44.195.159. Copyright RRS. For personal use only; all rights reserved Fig. 6 34-year-old man with tongue cancer., Coronal reformatted contrast-enhanced CT image shows incidental left renal agenesis and dilated left ureter (arrow) draining into cystic ipsilateral seminal vesicle (asterisk)., xial T2-weighted MR image shows connection between ureter and seminal vesicle (arrow). C Fig. 7 68-year-old man with hematuria and bladder cancer., xial delayed contrast-enhanced CT scan shows fluid-filled structure (arrow) in right hemipelvis could be mistaken for seminal vesicle cyst., Maximum-intensity-projection T2-weighted MR urographic image shows that fluid-filled structure in right pelvis is dilated ureter (arrow). C, xial delayed contrast-enhanced CT section at higher level than shows horseshoe kidney with markedly dysplastic right-sided moiety (arrow). Surgery confirmed that fluid-filled structure in right hemipelvis seen in was a dilated ureter arising from a dysplastic right-sided moiety of a horseshoe kidney, and also showed right ureter draining into prostate, with bilateral absence of seminal vesicles. 134 JR:189, July 2007
CT and MRI of Seminal Vesicles Downloaded from www.ajronline.org by 37.44.195.159 on 12/16/17 from IP address 37.44.195.159. Copyright RRS. For personal use only; all rights reserved Fig. 8 Contrast-enhanced axial CT scan in 84-yearold man with history of prior nephrectomy for renal cell carcinoma. Large fluid-filled bladder diverticulum (asterisk) arising off bladder posteriorly could be mistaken for seminal vesicle cyst. Fig. 9 xial T2-weighted MR image in 72-year-old man with prostate cancer. Large midline müllerian duct cyst (arrow) is seen posterior to prostate. Midline location is typical of such cyst and is a useful feature for differentiating from seminal vesicle cyst. Fig. 10 Endorectal seminal vasography (or vesiculography) in 42-year-old man with infertility. This study is helpful in confirming that periprostatic structure is due to dilated ejaculatory duct (arrow) upstream from obstruction of entrance of ejaculatory duct into prostatic urethra. Injection of contrast material under endorectal sonographic guidance both opacifies dilated obstructed duct and confirms that it is obstructed, because contrast material does not pass into prostatic urethra. JR:189, July 2007 135