eMedicine Specialties > Radiology > Genitourinary

Cryptorchidism

Vikram S Dogra, MD, Professor of Diagnostic Radiology, Urology, and Biomedical Engineering, University of Rochester School of Medicine; Director, Division of Ultrasound, Associate Chair of Education and Research, Department of Imaging Sciences, University of Rochester Medical Center

Updated: Mar 2, 2010

Introduction

Background

Cryptorchidism is defined as failure of the testis to descend from its intra-abdominal location into the scrotum. The exact etiology of cryptorchidism is not known. In one third of patients, the condition is bilateral. Ultrasound (US), CT, MRI, arteriography, and laparoscopy are used for diagnosis.

Orchiopexy is the treatment of choice and usually is performed in patients aged 2-10 years. A cryptorchid testis, as shown in the image below, is 20-48 times more likely to undergo malignant degeneration than a normal testis. Orchiopexy does not alter the risk of malignant transformation. The incidence of malignant transformation also is increased in the unaffected testis. Consider hormone treatment with either human chorionic gonadotropin or gonadotropin-releasing hormone analogues for palpable high-scrotal position of the testis; however, efficacy is less than 20%. Surgical treatment is most effective and reliable.

Longitudinal sonogram of the right cryptorchid testis at the level of the inguinal canal. Intratesticular spectral Doppler waveform demonstrates normal low-resistance pattern of flow.

Pathophysiology

A normal testis develops in the celomic cavity and begins to descend into the scrotum at 36 weeks, guided by the contractile cordlike structure termed the gubernaculum testis. The distal bulbous portion of the gubernaculum testis is termed the pars infravaginalis gubernaculi. After complete descent into the scrotum, the gubernaculum testis atrophies; however, it persists if the descent is not complete.

Frequency

United States

Incidence in premature male infants is 9.2-30%. In full-term infants, the incidence is 3.3-5.8%, and in infants aged 1 year, it is 0.8%.

International

Refer to frequency in the US.

Mortality/Morbidity

The lifetime risk of death from testicular malignancy in men of any age with undescended testis is approximately 9.7 times the risk in men with normally descended testis.

• Infertility: This condition is observed in 40% of patients with unilateral and 70% of patients with bilateral cryptorchidism.
• Malignant degeneration: Testicular malignancies occur in 10% of men with cryptorchid testis. The incidence of malignant degeneration in an undescended testis is reportedly as high as 48 times greater than in a normal testis. Seminoma is the most commonly reported malignancy.
• Torsion: This rare condition, if present, usually is secondary to the presence of a mass.

Race

No racial predilection is known.

Sex

Cryptorchidism is observed only in males.

Age

Cryptorchidism usually presents at birth or by preadolescence; however, it can present at any age. Avoid intervention before age 1 year because of the possibility of spontaneous descent.

Anatomy

Testicular size depends on age and stage of sexual development. Before age 12 years, testicular volume is 1-2 mL. Mean testicular volume at age 16 years is 14 mL.

US is the most frequently used imaging study for the testicle. On US, prepubertal testes are of low-to-medium level echogenicity. A normal adult testis has medium level echoes and measures 5 X 3 X 2 cm. The tunica albuginea is the fibrous covering of the testicle. Septa extend from the tunica albuginea into the testicle, dividing the testes into lobules. The posterior surface of the tunica albuginea is reflected into the interior of the gland, forming the incomplete septum termed the mediastinum of the testis. Sonographically, this is seen as an echogenic band running across the testis.

Each lobule is composed of many seminiferous tubules that open via tubules (tubuli recti) into dilated spaces termed the rete testes within the mediastinum. These in turn communicate via efferent ductules in the epididymal head. The epididymis is composed of a head, body, and tail, the ducts of which continue as the vas deferens in the spermatic cord.

Presentation

Patients present with the condition or the parents bring the child with nonpalpable testis.^{[4,5 ]}

Physical examination reveals a nonpalpable testis in the scrotum. The most common location of the cryptorchid testis is in the inguinal canal (72%), followed by prescrotal (20%) and abdominal (8%) locations.

The primary treatment of cryptorchid testis is orchiopexy.

Preferred Examination

US is the first imaging modality performed on a cryptorchid testis for the following reasons:

• Of cryptorchid testes, 72% are in the inguinal canal; therefore, they are easily accessible to US examination.
• US is readily available.
• US is easy to schedule.

If US cannot identify the testis (US effectively detects cryptorchid testis below the level of the internal inguinal ring), MRI and CT are the subsequent modalities of choice. Both can detect an abdominal testis.

Laparoscopy is performed if MRI and CT cannot localize the testis.^{[6 ]}

Limitations of Techniques

• US cannot detect an intra-abdominal testis.
• CT uses radiation and does not have multiplanar capability.
• MRI has better soft-tissue contrast and multiplanar capability; however, when the testis is higher in the abdomen, the presence of bowel loops lowers the sensitivity for detecting the cryptorchid testis.
• Laparoscopy is invasive and expensive.

Differential Diagnoses

Other Problems to Be Considered

Testicular ectopia (normal descent but abnormal location, such as perineum, femoral, suprapubic regions; in nonpalpable testis in the scrotum search these areas to exclude ectopia, which is rare in the contralateral hemiscrotum)

Retractile testis (often bilateral, normal condition; commonly seen in prepubertal boys; absent in adults)

Congenital absence (anorchia; rare, 4% of patients who clinically have an undescended testis actually have unilateral absence)

Atrophic testis (usually secondary to torsion; no color flow Doppler or contrast enhancement seen)

Lymph node (fatty hilum, characteristic location adjacent to vessels helps identification)

Pars infravaginalis gubernaculi (occasionally mistaken for testis)

Hypospadias and inguinal hernia (associated conditions)

Computed Tomography

Findings

Cryptorchid testis is seen as an oval soft-tissue mass along the expected course of testicular descent. Uniform enhancement is seen with intravenous (IV) radiographic contrast.

Degree of Confidence

CT is almost as accurate as US in detecting an undescended testis in the inguinal region. CT and MRI are much better than US in detecting an undescended testis that is located abdominally. In 1 study evaluating undescended testis, CT and US accuracy were 96% and 91%, respectively.

False Positives/Negatives

A lymph node can be differentiated readily by the presence of fatty hilum and its characteristic location.

Magnetic Resonance Imaging

Findings

Perform MRI from the level of the kidneys to the level of the pelvic outlet. The pulse sequences used are T1, T2, and postgadolinium T1-weighted images in the axial and coronal planes. An oval mass that appears as low signal on T1-weighted images and high signal on T2-weighted images is characteristic of an undescended testis. Identification of the mediastinum testis is helpful.

Gadolinium-based contrast agents have been linked to the development of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). The disease has occurred in patients with moderate to end-stage renal disease after being given a gadolinium-based contrast agent to enhance MRI or MRA scans. NSF/NFD is a debilitating and sometimes fatal disease. Characteristics include red or dark patches on the skin; burning, itching, swelling, hardening, and tightening of the skin; yellow spots on the whites of the eyes; joint stiffness with trouble moving or straightening the arms, hands, legs, or feet; pain deep in the hip bones or ribs; and muscle weakness.

Degree of Confidence

MRI detects the malignant degeneration in cryptorchid testis well.

False Positives/Negatives

Occasionally, bowel loops and lymph nodes can mimic the undescended testis. CT is much better at differentiating the undescended testis from the bowel loop.

Ultrasonography

Findings

The most common location of cryptorchid testis is the inguinal canal (72%), followed by prescrotal (20%) and abdominal (8%) locations. The presence of an oval mass in the inguinal canal (relatively hypoechoic in echo texture with echogenic mediastinum) is diagnostic.^{[7 ]}

Degree of Confidence

US is the modality of choice for imaging a cryptorchid testis for the following reasons:

• Of cryptorchid testes, 72% are in the inguinal canal; therefore, they are easily accessible.
• US is readily available.
• US is easy to schedule.

False Positives/Negatives

Rarely, an undescended testis can be confused with inguinal hernia; real time peristalsis confirms the presence of bowel.

Persistence of pars infravaginalis gubernaculi has been mistaken for the testis. The presence of an echogenic band (mediastinum testis) identifies the maldescended testis.

Angiography

Findings

Testicular venography has fallen out of favor because of the availability of noninvasive tests. The following findings are diagnostic:

• Demonstrated presence of the pampiniform plexus
• Visualization of testicular parenchyma
• A blind-ending testicular vein (usually indicates absent testis)

Degree of Confidence

Angiography is accurate but invasive; thus, it is not preferred. Gadolinium infusion MR venography is an alternative noninvasive method of evaluating the undescended testis, especially the vanishing testis. It is superior to MR imaging alone.

Intervention

No radiologic intervention exists.^{[8,9 ]}

Patient Education: For excellent patient education resources, visit eMedicine's Men's Health Center. Also, see eMedicine's patient education article Understanding the Male Anatomy.

Multimedia

Media file 1: Longitudinal sonogram of the right cryptorchid testis at the level of the inguinal canal. Intratesticular spectral Doppler waveform demonstrates normal low-resistance pattern of flow.

References

1. Gordon M, Cervellione RM, Morabito A, Bianchi A. 20 years of transcrotal orchidopexy for undescended testis: Results and outcomes. J Pediatr Urol. Nov 26 2009;[Medline].

2. Akre O, Pettersson A, Richiardi L. Risk of contralateral testicular cancer among men with unilaterally undescended testis: a meta analysis. Int J Cancer. Feb 1 2009;124(3):687-9. [Medline].

3. Canavese F, Mussa A, Manenti M, Cortese MG, Ferrero L, Tuli G, et al. Sperm count of young men surgically treated for cryptorchidism in the first and second year of life: fertility is better in children treated at a younger age. Eur J Pediatr Surg. Dec 2009;19(6):388-91. [Medline].

4. Wood HM, Elder JS. Cryptorchidism and testicular cancer: separating fact from fiction. J Urol. Feb 2009;181(2):452-61. [Medline].

5. Main KM, Skakkebaek NE, Toppari J. Cryptorchidism as part of the testicular dysgenesis syndrome: the environmental connection. Endocr Dev. 2009;14:167-73. [Medline].

6. Stothers L, Shadgan B, Macnab A. Urological applications of near infrared spectroscopy. Can J Urol. Dec 2008;15(6):4399-409. [Medline].

7. Dogra VS, Bhatt S, Rubens DJ. Sonographic evaluation of testicular torsion. Ultrasound Clin. 2006;1:55-66.

8. Martin JM, Gorayski P, Zwahlen D, Fay M, Keller J, Millar J. Is Radiotherapy A Good Adjuvant Strategy for Men with A History of Cryptorchism and Stage I Seminoma?. Int J Radiat Oncol Biol Phys. Apr 11 2009;[Medline].

9. Trsinar B, Muravec UR. Fertility potential after unilateral and bilateral orchidopexy for cryptorchidism. World J Urol. Apr 8 2009;[Medline].

10. Bree RL, Hoang DT. Scrotal ultrasound. Radiol Clin North Am. Nov 1996;34(6):1183-205. [Medline].

11. Dogra VS, Gottlieb RH, Oka M. Sonography of the scrotum. Radiology. Apr 2003;227(1):18-36.

12. Fritzsche PJ, Hricak H, Kogan BA. Undescended testis: value of MR imaging. Radiology. Jul 1987;164(1):169-73. [Medline].

13. Gill B, Kogan S. Cryptorchidism. Current concepts. Pediatr Clin North Am. Oct 1997;44(5):1211-27. [Medline].

14. Husmann DA, Levy JB. Current concepts in the pathophysiology of testicular undescent. Urology. Aug 1995;46(2):267-76. [Medline].

15. Khatwa UA, Menon PS. Management of undescended testis. Indian J Pediatr. Jun 2000;67(6):449-54. [Medline].

16. Kiely EA. Scientific basis of testicular descent and management implications for cryptorchidism. Br J Clin Pract. Jan-Feb 1994;48(1):37-41. [Medline].

17. Koo HP, Bloom DA. Laparoscopy for the nonpalpable testis. Semin Laparosc Surg. Mar 1998;5(1):40-6. [Medline].

18. Krone KD, Carroll BA. Scrotal ultrasound. Radiol Clin North Am. Mar 1985;23(1):121-39. [Medline].

19. Nguyen HT, Coakley F, Hricak H. Cryptorchidism: strategies in detection. Eur Radiol. 1999;9(2):336-43. [Medline].

20. Wolverson MK, Houttuin E, Heiberg E. Comparison of computed tomography with high-resolution real-time ultrasound in the localization of the impalpable undescended testis. Radiology. Jan 1983;146(1):133-6. [Medline].

Keywords

cryptorchidism, undescended testis, maldescended testis, atrophic testis, anorchia

Contributor Information and Disclosures

Author

Vikram S Dogra, MD, Professor of Diagnostic Radiology, Urology, and Biomedical Engineering, University of Rochester School of Medicine; Director, Division of Ultrasound, Associate Chair of Education and Research, Department of Imaging Sciences, University of Rochester Medical Center
Vikram S Dogra, MD is a member of the following medical societies: American College of Radiology, American Institute of Ultrasound in Medicine, American Roentgen Ray Society, Association of Program Directors in Radiology, Radiological Society of North America, Society of Radiologists in Ultrasound, and Society of Uroradiology
Disclosure: Nothing to disclose.

Medical Editor

John L Haddad, MD, Clinical Associate Professor, Department of Radiology, Weill Medical College of Cornell University; Director of Body MRI, Department of Radiology, Methodist Hospital in Houston
John L Haddad, MD is a member of the following medical societies: American College of Radiology, American Medical Association, and Radiological Society of North America
Disclosure: Nothing to disclose.

Pharmacy Editor

Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand
Disclosure: Nothing to disclose.

Managing Editor

Matthew D Rifkin, MD, Director, Department of Radiology, Good Samaritan Hospital
Disclosure: Nothing to disclose.

CME Editor

Robert M Krasny, MD, Resolution Imaging Medical Corporation
Robert M Krasny, MD is a member of the following medical societies: American Roentgen Ray Society and Radiological Society of North America
Disclosure: Nothing to disclose.

Chief Editor

Eugene C Lin, MD, Consulting Radiologist, Virginia Mason Medical Center; Clinical Assistant Professor of Radiology, University of Washington School of Medicine
Eugene C Lin, MD is a member of the following medical societies: American College of Nuclear Medicine, American College of Radiology, Radiological Society of North America, and Society of Nuclear Medicine
Disclosure: Nothing to disclose.

Hamid Mojibian, MD, is gratefully acknowledged for contributions made to this topic.

Related eMedicine topics

Cryptorchidism (from Urology)

Cryptorchidism (from Pediatrics: Surgery)

Bedside Ultrasonography, Testicular Evaluation

Testicular Torsion

Prepubertal Testicular and Paratesticular Tumors

Clinical guidelines

Cryptorchidism. In: Guidelines on Paediatric Urology

Laparoscopy for Non-palpable Testicle. In: Diagnostic Laparoscopy Guidelines

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