You are in: eMedicine Specialties > Radiology > GENITOURINARY CryptorchidismArticle Last Updated: Apr 5, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: Vikram S Dogra, MD, Professor of Diagnostic Radiology, 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 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 Coauthor(s): Hamid Mojibian, MD, Radiology, Mercy Medical Center Editors: 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; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; Matthew D Rifkin, MD, Director, Department of Radiology, Good Samaritan Hospital; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; Eugene C Lin, MD, Consulting Staff, Department of Radiology, Virginia Mason Medical Center Author and Editor Disclosure Synonyms and related keywords: undescended testis, maldescended testis, atrophic testis, anorchia INTRODUCTIONSection 2 of 10
  BackgroundCryptorchidism 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 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. PathophysiologyA 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. FrequencyUnited StatesIncidence 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%. InternationalRefer to frequency in the US. Mortality/MorbidityThe 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.
RaceNo racial predilection is known. SexCryptorchidism is observed only in males. AgeCryptorchidism 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. AnatomyTesticular 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. Clinical DetailsPatients present with the condition or the parents bring the child with nonpalpable testis. 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 ExaminationUS is the first imaging modality performed on a cryptorchid testis for the following reasons:
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. Limitations of Techniques
DIFFERENTIALSSection 3 of 10
Other Problems to Be ConsideredTesticular 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) CT SCANSection 4 of 10
FindingsCryptorchid 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 ConfidenceCT 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/NegativesA lymph node can be differentiated readily by the presence of fatty hilum and its characteristic location. MRISection 5 of 10
FindingsPerform 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 (gadopentetate dimeglumine [Magnevist], gadobenate dimeglumine [MultiHance], gadodiamide [Omniscan], gadoversetamide [OptiMARK], gadoteridol [ProHance]) have recently been linked to the development of nephrogenic systemic fibrosis (NSF) or nephrogenic fibrosing dermopathy (NFD). For more information, see the eMedicine topic Nephrogenic Fibrosing Dermopathy. 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. As of late December 2006, the FDA had received reports of 90 such cases. Worldwide, over 200 cases have been reported, according to the FDA. 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 movingor straightening the arms, hands, legs, or feet; pain deep in the hip bones or ribs; and muscle weakness. For more information, see the FDA Public Health Advisory or Medscape. Degree of ConfidenceMRI detects the malignant degeneration in cryptorchid testis well. False Positives/NegativesOccasionally, bowel loops and lymph nodes can mimic the undescended testis. CT is much better at differentiating the undescended testis from the bowel loop. ULTRASOUNDSection 6 of 10
FindingsThe 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. Degree of ConfidenceUS is the modality of choice for imaging a cryptorchid testis for the following reasons:
False Positives/NegativesRarely, 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. ANGIOGRAPHYSection 7 of 10
FindingsTesticular venography has fallen out of favor because of the availability of noninvasive tests. The following findings are diagnostic:
Degree of ConfidenceAngiography 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. INTERVENTIONSection 8 of 10
No radiologic intervention exists. 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. MULTIMEDIASection 9 of 10
REFERENCESSection 10 of 10
Article Last Updated: Apr 5, 2007 | ||||||||||||
