PEDIATRICS Vol. 110 No. 4 October 2002, pp. 748-751
Ultrasonography Is Unnecessary in Evaluating Boys With a Nonpalpable Testis
Jack S. Elder, MD
From the Division of Pediatric Urology, Rainbow Babies and Children’s Hospital, Department of Urology, Case Western Reserve University School of Medicine, Cleveland, Ohio
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ABSTRACT
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Objective. An inguinal sonogram often is obtained in boys with a nonpalpable testis to "localize" the testis, ie, determine whether the testis is present. The results of ultrasonography in boys with a nonpalpable testis were analyzed.
Methods. The records of boys who were referred to a pediatric urology center with a diagnosis of nonpalpable testis and who had undergone inguinal sonography were reviewed. The results of sonography were compared with findings in the office as well as surgical findings.
Results. A total of 62 boys who were referred with a diagnosis of a nonpalpable testis and who had undergone a sonogram were reviewed. The sonogram was ordered by the primary care physician in 51 boys (82%) and by a general urologist in 11 cases (18%). The testis was identified by sonography in 12 (18%) of 66 cases, and all were localized to the inguinal canal. Physical examination by a pediatric urologist showed that 6 were in the scrotum and 6 were in the inguinal canal or perineum. Of the 54 testes that were not localized by the sonogram, 33 (61%) were palpable and 21 (39%) were nonpalpable. Of the truly nonpalpable testes, laparoscopy and abdominal/inguinal exploration identified the testis as abdominal in 10 cases and atrophic secondary to spermatic cord torsion in 11 cases.
Conclusion. Sonography is unnecessary in boys with a nonpalpable testis, because it rarely if ever localizes a true nonpalpable testis, and it does not alter the surgical approach in these patients.
Key Words: testis • undescended • ultrasonography • testis • nonpalpable • radiology
Abbreviations: CT, computerized tomography • MRI, magnetic resonance imaging
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INTRODUCTION
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Approximately 1% of boys have an undescended testis, 20% of which are nonpalpable.1 In boys with a nonpalpable testis, approximately 50% are abdominal, 45% are atrophic secondary to in utero spermatic cord torsion, and 5% are in the inguinal canal.2–4 Testes that are atrophic are known as vanishing testes and usually are in the scrotum; few are in the inguinal canal. An undescended testis has impaired spermatogenesis and is prone to malignant degeneration. The goal of management of a nonpalpable testis is to identify whether a viable testis is present and, if so, either perform an orchiopexy or, in selected cases, an orchiectomy. Often diagnostic laparoscopy is performed to assess whether the testis is intra-abdominal,2 although some prefer inguinal/abdominal exploration.5
Numerous radiologic studies have been used to try to "localize" the nonpalpable testis preoperatively, including retrograde venography, computerized tomography (CT), magnetic resonance imaging (MRI), and sonography.6–11 The concept of retrograde venography is that a viable testis will have a normal venous pattern, whereas an atrophic testis will have diminutive vessels. The test is invasive, requires anesthesia, and is not very accurate. CT and MRI are much more accurate in identifying a viable testis. However, both require either heavy sedation or general anesthesia in infants, and neither can show with 100% certainty that the testis is absent. Consequently, irrespective of the outcome of the CT or MRI, surgical exploration is necessary.
Abdominal and inguinal sonography for evaluation of a nonpalpable testis is appealing because it is noninvasive, it confers no radiation exposure, and it does not require sedation or general anesthesia. However, reports to date have not demonstrated significant efficacy in localizing the testis, because sonography rarely will identify a gonad if it is viable and intra-abdominal or if it is atrophic and in the scrotum or inguinal canal.9–11 Nevertheless, many primary care physicians obtain a sonogram before referring the child for surgical exploration. In addition, not infrequently, a testis that is not palpable by the referring physician can be palpated by a pediatric urologist. The goal of this study was to evaluate the results of sonography in a series of boys who were referred with a diagnosis of nonpalpable testis.
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METHODS
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The charts of boys who were referred to a pediatric urologist with the diagnosis of a nonpalpable testis and who had undergone an abdominal and inguinal sonogram performed with the purpose of localizing the nonpalpable testis were reviewed. The results of the sonogram, the physical examination in the office, and the findings at surgical exploration were recorded and analyzed. Boys who had prune belly syndrome or a chromosomal anomaly were excluded because nearly always they have bilateral abdominal testicles. In addition, boys who had had a previous inguinal surgical procedure such as a hernia repair or orchiopexy were excluded.
Boys were examined in the supine position with their shoes and pants removed. When the testis could not be palpated, often liquid soap was applied to the inguinal canal and abdomen to reduce friction. In boys diagnosed with a retractile testis in the office, patients did not undergo a surgical procedure. In boys whose palpable undescended testis was diagnosed in the pediatric urology office, inguinal exploration and orchiopexy were performed. In boys with a nonpalpable testis, diagnostic laparoscopy was performed, followed by abdominal orchiopexy (mobilization of the abdominal testis and fixation in the scrotum) when the testis was found to be intra-abdominal or just beyond the internal inguinal ring.2 When the vas and vessels were noted to enter the internal inguinal ring and there was no patent processus vaginalis, inguinal or scrotal exploration was performed and usually the testis was found to be in the scrotum secondary to perinatal spermatic cord torsion.
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RESULTS
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Evaluation by Referring Physician
A total of 62 boys who had a diagnosis of a nonpalpable testis by the referring physician and had undergone a sonogram before referral were reviewed. Of the patients, 58 (92%) had a unilateral nonpalpable testis and 4 (8%) were thought to have bilateral nonpalpable testes. Patient age at the time of ultrasound was 4 months to 14 years (mean: 4.5 years). The sonogram was ordered by the primary care physician in 51 boys (82%) and by a general urologist in 11 cases (18%). The sonogram was performed at an outside institution in 52 (93%) of 56 cases. The findings at sonography are shown in Table 1. The sonogram identified the testis in 12 (18%) of 66 cases, and all were identified as being in the inguinal canal.
Evaluation in Pediatric Urology Center
The results of the physical examination are shown in Table 2. Of the testes, 45 (68%) of 66 were palpable, and most were in the inguinal canal. Of the testes, 12 (18%) were in the scrotum and were diagnosed as retractile. There were no false-positive pediatric urological examinations, ie, cases in which a testis was deemed palpable but was found to be absent on surgical exploration.
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TABLE 2. 66 Nonpalpable Testes (by Referring Physician): Findings on Physical Examination and/or Surgical Exploration
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Of the 12 testes identified by ultrasonography, physical examination showed that 6 were in the scrotum and 6 were in the inguinal canal or perineum. Of the 54 testes that were not identified by the sonogram, 33 (61%) were palpable and 21 (39%) were nonpalpable. Laparoscopy and abdominal/inguinal exploration identified the testis as abdominal in 10 cases and atrophic secondary to spermatic cord torsion in 11 cases.
Of the boys with a unilateral nonpalpable testis at referral, 9 had had a previous physical examination by the primary care physician indicating that the testis was present. Physical examination identified the testis in the inguinal canal or scrotum in all 9 boys. In these boys, the sonogram showed that the testis was inguinal in 6 cases and was not identified in 3.
Whether sonography altered the pediatric urologic management was analyzed. In the 12 cases in which sonography identified an inguinal testis, all were palpable in the office, and approximately half were scrotal and retractile. In these boys, the sonogram did not alter management. In the 54 cases in which the sonogram failed to localize the testis, the testis was palpable in the office in 61%, and the sonogram could be considered a false negative in these patients. In the 21 cases in which the testis was not identified by sonogram and was nonpalpable in the office, abdominal/inguinal exploration was necessary to ascertain whether the testis was present. The only clinical situation in which sonography would alter management is if the ultrasound demonstrated a testis, whereas the physical examination disclosed a nonpalpable testis. This situation did not occur in this series. Consequently, this review did not identify any case in which sonography altered pediatric urologic management.
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DISCUSSION
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In this analysis, ultrasonography obtained by the referring physician has been demonstrated to lack benefit in most boys with a nonpalpable testis because 1) in most cases the testis could not be identified on sonography and 2) when it was localized, it was palpable in the pediatric urology office.
The goal of management in a boy with an undescended testis is to place the testis in the scrotum to maximize its potential for spermatogenesis, to allow screening for malignant degeneration in adolescence and adulthood, and to close the patent processus vaginalis, which usually is present in these boys.2 Most undescended testes are palpable in the inguinal canal, the superficial inguinal pouch, or the perineum, or they are gliding, ie, the testis glides back and forth between the external inguinal ring and upper scrotum. An orchiopexy in these boys is generally done through a small inguinal incision.
The nonpalpable testis presents a special diagnostic and therapeutic challenge, because approximately half are abdominal and viable, half are atrophic secondary to spermatic cord torsion in utero (also termed "vanishing testis"), and a small percentage are viable in the inguinal canal. It is critical to identify whether a viable testis is present and, if so, either perform an orchiopexy or an orchiectomy, because leaving a testis in an undescended position risks occult malignant degeneration in the future.
A variety of surgical approaches are used to assess the status of the nonpalpable testis. Many surgeons perform diagnostic laparoscopy under anesthesia to determine whether the testis is abdominal or has descended into the inguinal canal through the internal inguinal ring, and then proceed with orchiopexy when a viable testis is found.2 Another common approach is to perform a primary inguinal exploration and if the testis is not identified in either the inguinal canal or scrotum, then the exploratory procedure is extended into the peritoneal cavity.5
If an imaging study that would reliably demonstrate the status of the nonpalpable testis could be performed, then it is possible that the surgical procedure could be modified or even avoided, if the testis were proved to be absent. Sonography is the least invasive form of imaging. When it is used to assess whether a nonpalpable testis is present, the inguinal canal and lower abdomen are imaged. Unfortunately, nonpalpable testes usually are not inguinal. Furthermore, if the testis is abdominal, then sonography will fail to identify the gonad. If the testis is atrophic secondary to perinatal spermatic cord torsion, then a viable testis will not be identified. Consequently, it seems logical that sonography would not be useful in "localizing" a nonpalpable testis. Nevertheless, in our center, many boys who were seen with a nonpalpable testis have undergone a sonogram ordered by the referring physician. The purpose of this study was to assess whether the ultrasound was beneficial in these patients.
In this series of patients, it was found that in approximately 60% of boys who were referred with a diagnosis of a nonpalpable testis and had undergone sonography, the testis was palpable (Table 1). In most cases, the testis was in the inguinal canal, although in some cases it was scrotal but retractile. In these boys with a palpable testis, the sonogram was unnecessary. In the boys with a true nonpalpable testis, sonography failed to demonstrate a testis in any patient. When sonography demonstrated a testis to be present, physical examination always disclosed a viable testis (Table 2). Furthermore, in the 54 cases in which the testis was palpable in the pediatric urology office, sonography failed to demonstrate the testis in 33 (61%). Our results are similar to those reported by another pediatric urology center, which found that 57% of boys with a referral diagnosis of a nonpalpable testis had a palpable testis and found poor correlation between a variety of imaging studies and findings at exploration.12 It seems clear that sonography is unreliable and unnecessary in the evaluation of boys with a nonpalpable testis.
It was surprising that a significant number of boys who had undergone sonography were found to have a palpable testis. When examining a boy with a suspected undescended testis, it is helpful to have the child remove his shoes, pants, and underwear and to encourage him to relax by taking deep breaths during the examination. Placing soap on the abdomen and inguinal canal reduces friction and may increase the sensitivity of the examiner’s hand. It also should be recognized that the cryptorchid testis typically is not tightly anchored in 1 position. Rather, undescended testes typically have a long mesentery. At times, some inguinal testes slide back into the abdominal cavity, making them temporarily nonpalpable. In addition, some descended testes are retractile; during examination, the cremaster muscle contracts, causing the testis to migrate temporarily back into the inguinal canal. Consequently, in a boy with a suspected undescended testis, the technique of physical examination is important in determining whether a testis is undescended and, if so, whether it is palpable.
Are imaging studies ever beneficial in boys with a nonpalpable testis? CT and MRI are more reliable than sonography in localizing the nonpalpable testis.7,8,13,14 However, even if the study localizes the testis, an orchiopexy is necessary. If the study fails to demonstrate a viable testis, surgical exploration is still necessary, because neither CT nor MRI has been shown to be reliable in diagnosing a vanishing testis. Consequently, routine preoperative imaging seems unnecessary. One exception may be obese boys, in whom physical examination for an undescended testis can be difficult. De Filippo et al15 proposed using MRI in such patients, and in this circumstance the imaging seems reasonable, because laparoscopy is more difficult and has a higher complication rate in obese patients. The other situation in which we have found sonography to be helpful is in the newborn with genital ambiguity, in which pelvic ultrasound, adrenal ultrasound, and inguinal ultrasound are performed to look for a uterus, enlarged adrenals, and inguinal testes, respectively.
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CONCLUSION
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We have found that sonography is unnecessary in boys with a nonpalpable testis, because it rarely, if ever, localizes a true nonpalpable testis, and it does not alter the surgical approach in these patients. The use of this form of preoperative imaging is discouraged.
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FOOTNOTES
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Received for publication Oct 22, 2001; Accepted Mar 25, 2002.
Address correspondence to Jack S. Elder, MD, Division of Pediatric Urology, Rainbow Babies and Children’s Hospital, 11100 Euclid Ave, Cleveland, OH 44106. E-mail: jse{at}po.cwru.edu
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REFERENCES
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- Elder JS. The undescended testis: hormonal and surgical management.
Surg Clin North Am.1988; 68
:983
–1006[ISI][Medline]
- Elder JS. Laparoscopy for the impalpable testis: significance of the patent processus vaginalis.
J Urol.1994; 152
:776
–778[ISI][Medline]
- Diamond DA, Caldamone AA. The value of laparoscopy for 106 impalpable testes relative to clinical presentation.
J Urol.1992; 148
:632
–634[ISI][Medline]
- Moore RG, Peters CA, Bauer SB, Mandell J, Retik AB. Laparoscopic evaluation of the nonpalpable testis: a prospective assessment of accuracy.
J Urol.1994; 151
:728
–731[ISI][Medline]
- Kirsch AJ, Escala J, Duckett JW, et al. Surgical management of the nonpalpable testis: the Children’s Hospital of Philadelphia experience.
J Urol.1998; 159
:1340
–1343[CrossRef][ISI][Medline]
- Weiss RM, Glickman MG, Lytton B. Clinical implications of gonadal venography in the management of the non-palpable undescended testis.
J Urol.1979; 121
:745
–749[ISI][Medline]
- Wolverson MK, Jagannadharao B, Sundaram M, Riaz MA, Nalesnik WJ, Houttuin E. CT in localization of impalpable testes.
AJR Am J Roentgenol.1980; 134
:725
–729[Abstract]
- Fritzsche PJ, Hricak H, Kogan BA, Winkloer ML, Tanagho EA. Undescended testis: value of MR imaging.
Radiology.1987; 164
:169
–173[Abstract/Free Full Text]
- Weiss RM, Carter AR, Rosenfield AT. High resolution real-time ultrasonography in the localization of the undescended testis.
J Urol.1986; 135
:936
–938[ISI][Medline]
- Kullendorff CM, Hederstrom E, Forsberg L. Preoperative ultrasonography of the undescended testis.
Scand J Urol Nephrol.1985; 19
:13
–15[ISI][Medline]
- Malone PS, Guiney EJ. A comparison between ultrasonography and laparoscopy in localizing the impalpable undescended testis.
Br J Urol.1985; 57
:185
–186[ISI][Medline]
- Hrebinko RL, Bellinger MF. The limited role of imaging techniques in managing children with undescended testes.
J Urol.1993; 150
:458
–460[ISI][Medline]
- Rajfer J, Tauber A, Zinner N, Naftulin E, Worthen N. The use of computerized tomography scanning to localize the impalpable testis.
J Urol.1983; 129
:972
–974[ISI][Medline]
- Maughnie M, Vanzulli A, Paesano P, et al. The accuracy of magnetic resonance imaging and ultrasonography compared with surgical findings in the localization of the undescended testis.
Arch Pediatr Adolesc Med.1994; 148
:699
–703[Abstract]
- De Filippo RE, Barthold JS, Gonzalez R. The application of magnetic resonance imaging for the preoperative localization of nonpalpable testis in obese children: an alternative to laparoscopy.
J Urol.2000; 164
:154
–155[CrossRef][ISI][Medline]
PEDIATRICS (ISSN 1098-4275). ©2002 by the American Academy of Pediatrics
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ABSTRACT
INTRODUCTION
