Carcinoma-in-situ of the Testis Is Ultrasound of the Testes Useful as a Screening Method?

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1 R E V I E W A R T I C L E Carcinoma-in-situ of the Testis Is Ultrasound of the Testes Useful as a Screening Method? Suzan Lenz 1 *, Aleksander Giwercman 2 Testicular germ cell cancer is preceded by a pre-invasive stage called carcinoma-in-situ (CIS). The majority, if not all cases of CIS will progress into invasive cancer. Today, the only reliable way of diagnosing CIS is by performing open testicular biopsy. There is an ongoing search for non-invasive techniques for diagnosing early testicular neoplasia. The possibility of using ultrasound of the testis as a screening procedure has been investigated, and this review focuses on the available literature on the subject. It is clearly demonstrated that an abnormal echopattern seen by ultrasound of the testis is suspicious of CIS. The normal echopattern is slightly irregular. The abnormal patterns consist of either a very irregular echopattern or a pattern with bright echogenic points also named microlithiasis or microcalcifications. The abnormal pattern is found in only 2 5% of men from the general population. The risk of CIS with a normal echopattern, even in a high risk group, is estimated to be below 3%. The risk of CIS with the abnormal echopattern is 6 48% and relates to the degree of microlithiasis and the underlying disease. Our conclusion is that ultrasound is a valuable tool in the examination of men with an increased risk of testicular cancer to detect pre-malignant stages, but large follow-up studies of men from general population are needed in order to find out whether it can be recommended as a general screening method. KEY WORDS CIS, echopattern, microlithiasis, screening, testis, ultrasound J Med Ultrasound 2008;16(4): Introduction Testicular germ cell cancer (TGCC) is the most common malignancy in the year-old age group. Although the survival rates are excellent, disseminated TGCC can have a lethal outcome. Furthermore, the intensive treatment of metastasing cancer disease by chemotherapy is associated with a number of side effects. These problems can be avoided if the malignant disease is diagnosed at an early stage, ideally at the carcinoma-in-situ (CIS) stage. In searching for proper diagnostic methods for early detection of TGCC, ultrasound has is put forward as a possible option. This review aims to summarize the current clinical knowledge in relation to possibilities and limitations in use of Received: September 18, 2008 Accepted: September 30, Gynecologic Clinic, Hyldegaardsvej 4, 2920 Charlottenlund, Denmark and 2 Reproductive Medicine Centre, Lund University, Malmö University Hospital, Entrance 74, SE Malmö, Sweden. *Address correspondence to: Dr. Suzan Lenz, Gynecologic Clinic, Hyldegaardsvej 4, 2920 Charlottenlund, Denmark. suzanlenz@dadlnet.dk 256 J Med Ultrasound 2008 Vol 16 No 4 Elsevier & CTSUM. All rights reserved.

2 CIS Testis and Ultrasound ultrasonic examination as an instrument in diagnosing testicular malignancy at an early, pre-invasive stage. Prevalence of Testis Cancer and Geographical Distribution Although not being among the most prevalent malignancies TGCC is the most common cancer disease in males aged 20 to 40 years. The epidemiology of TGCC has some peculiarities which point to the impact of environmental and lifestyle related factors, but additionally is suggestive of genetics, in relation to the aetiology of this disease. During the past five to six decades a steady increase in the incidence of TGCC has been observed world-wide [1,2]. The oldest reliable register data origin from Denmark where a nationwide cancer register has been established since In this country the incidence of TGCC is now 4 5 times higher than it was in the 1940s. This increase is not due to improvement in the diagnostic procedures. Untreated TGCC is lethal and in this age group such an outcome will lead to an investigation of possible causes. Furthermore, the external position of the testis makes this organ easy to investigate and the risk of overlooking a tumor is negligible. Interestingly Denmark leads the world in the incidence of TGCC, for the past few years being accompanied by Norway [1]. In these countries the life time risk of TGCC is about 1%. The reason why this malignancy is much more common now than it was few decades ago is unknown. It has also not been explained why there is a huge discrepancy in the incidence of TGCC between populations which geographically, socially and genetically are very closely related. Thus the risk of TGCC is twice as high in Denmark as compared to Sweden and five times higher than in Finland. Interestingly, despite these geographical differences, the rate of increase in the incidence has been similar in all Caucasians populations from which reliable data are available. These epidemiological features point to the impact of environmental and/or lifestyle related factors in the aetiology of TGCC [3] and it is now strongly believed that these factors are affecting the developing testis in early foetal life [4]. These assumptions are strengthened by finding that the risk of TGCC in the first generation of immigrants are close to that in the country of origin, whereas in the second generation, the risk of TGCC is at the level of the country where these subjects are living [5 7]. However, genetic factors also seem to play a role. The risk of TGCC is significantly lower in Afro- Americans as compared to Caucasians living in the USA. Furthermore, sons and brothers of TGCC patients have an increased risk of developing this malignancy [8]. Thus, the available epidemiological data point to the impact of genetic as well as environmental and/or lifestyle related factors in the aetiology of TGCC. Carcinoma-in-situ Testis In 1972 Skakkebæk reported on two cases of TGCC preceded by the presence of intra-tubular atypical testicular cells, which he called CIS cells [9]. These cells possessed many of the cytological characteristics of malignancy, including large and irregular nuclei, multiple mitoses and glycogen rich cytoplasm (Fig. 1). Their migration to the interstitial SC CIS Fig. 1. Carcinoma-in-situ (CIS) of the testis. Hematoxylin and eosin staining. Note the malignant characteristics of CIS cells large and irregular nucleus and abundant cytoplasm. Apart from the CIS cells, Sertoli cells (SC) are the only cell type present within the tubules. J Med Ultrasound 2008 Vol 16 No 4 257

3 S. Lenz, A. Giwercman testicular space and to rete testis represented histological evidence of their invasive potential [10]. It is now evident that both seminomatous and non-seminomatous germ cell cancers, except the spermatocytic seminoma, are preceded by the stage of CIS [11]. Although conclusive evidence has not yet been provided, it seems probable that most, if not all cases of CIS progress into the invasive stage of TGCC. Thus follow up cases of CIS found in infertile men and in the contralateral testis of patients with unilateral TGCC have shown that at least 70% of these men develop invasive cancer in 7 years [12]. In cases where multiple biopsies were performed over time, in untreated cases the disappearance of CIS has never been reported. The might indicate that all cases, CIS sooner or later develops into invasive cancers. Epidemiological data, morphological and molecular studies have pointed to early foetal life as the time that the CIS cells form [11,13]. These cells seem to be closely related to the foetal germ cells and following malignant transformation, remain dormant until the post-pubertal period when, whilst probably under the influence of sex steroids and/or gonadotropins, they start to proliferate and to differentiate into seminoma or non-seminoma [14]. Diagnosed at the stage of CIS, TGCC can easily be prevented. In unilateral cases, simple orchidectomy is curative. In bilateral cases, or if the CIS is found in the contralateral testis of a patients with unilateral TGCC, castration can be avoided by giving a localized fractionated irradiation of Gy to the CIS bearing gonad. This therapy can prevent the development of cancer in the testis in question [15]. The fact that TGCC is preceded by the CIS stage which has a foetal origin, and with a very high probability of developing into a cancer which can be prevented if the malignancy is diagnosed at the pre-invasive stage, makes CIS a very attractive target for early screening for testicular malignancy. Although the results of TGCC treatment are excellent, it should be kept in mind that a few cases of the disease affecting young males may have a lethal outcome. Furthermore, radiotherapy and chemotherapy, which can be avoided if the disease is diagnosed at CIS stage, may have serious long term effects including infertility and even an increase of metabolic syndrome or cardiovascular diseases [16]. Testicular Biopsy and Potential Markers for Diagnosing CIS The biological features of testicular CIS makes it an attractive target for early diagnosis and, thereby, prevention of TGCC. If the method for diagnosing CIS is highly sensitive, one single test performed in young adulthood should be enough to exclude the risk of developing testicular cancer [17]. However so far no large screening programmes for this condition have yet been established. The reason is a lack of proper screening methods. Due to the relatively low incidence of TGCC, even in high risk populations such as Denmark and Norway, the method of diagnosing CIS needs not only to be highly sensitive but also very specific. Furthermore, the method should preferably be non-invasive and relatively cheap, if not to be applied only to high risk groups. Despite the fact that several CIS tissue markers have been reported [13,17], screening for CIS by performing blood tests has not proven successful. Another option is to look for CIS cells in the ejaculate, since they, like normal germ cells, are supposed to be released from the lumen of the seminiferous tubules into the semen [17 19]. During the past more than 20 years, attempts have been made to develop a reliable method for detection of CIS germ cells in semen, by use of flow cytometry [20], in situ hybridization [21] and cytochemistry [18,19]. The last technique seems to be the most successful, but although some progress in the development of an assay for diagnosing CIS by semen analysis has been made, this method is not ready for clinical application [13]. The standard method for reliable detection of CIS is open testicular biopsy, followed by examination of a hematoxylin-eosin (Fig. 1) and/or immunohistochemically stained tissue sample (Fig. 2) [22]. 258 J Med Ultrasound 2008 Vol 16 No 4

4 CIS Testis and Ultrasound Fig. 2. CIS immunohistochemically stained with the monoclonal antibody M2A. Tubules with CIS cells are diffusely spread all over the testis. When examined by a trained pathologist, the specificity of diagnosing CIS by histological examination of testicular tissue is 100%. Even the sensitivity of detecting CIS seems to be rather high. Thus, it was shown that a single biopsy will detect CIS in approximately 91% of cases when CIS is present in the testis [23]. It has, additionally, been suggested that the number of false negative results may be reduced by performing two-site biopsy and/or the use of specific immunohistochemical markers [23,24]. These favorable figures apply for an open surgical biopsy. CIS cells have been found in a needle and fine needle biopsy, but the diagnostic accuracy of these tests has not yet been investigated [25]. Although testicular biopsy appears to be a reliable tool in diagnosing CIS, the invasive nature of this technique makes it improper for large scale screening. Additionally the use of biopsy is today limited to high risk patients, such as those having unilateral TGCC, or selected groups of men with a history of cryptorchidism and/or infertility problems. Ultrasound as a Potential Screening Method for CIS Ultrasound was brought into focus due to its non-invasiveness and the relatively accessibility of the necessary equipment. Furthermore, ultrasound Fig. 3. Microlithiasis of the testis visualized by ultrasound. The testis is the round structure filling the upper half of the picture. The testes contains innumerable bright (white) echogenic points. The delineation of the testis is not sharp. This correlates with a soft testis, which is a sign of low sperm quality. scanning is painless and safe. As case studies highlighted echogenic differences in some patients with early malignancies, ultrasound scanning came into focus in the early eighties as a possible tool in diagnosing CIS [26]. It was especially clear that some testes showed bright echogenic points on ultrasound, and this phenomenon was later named microcalcifications or microlithiais (Fig. 3). The presence of microcalcifications has been partly confirmed by mammographic technique [27]. Microlithiasis can to some extent be correlated to calcified bodies in the tubules histologically [28,29] (Fig. 4). Microlithiasis is part of the abnormal echopattern dealt with in this review. The Echopattern in Non Selected Men The echopattern in non selected men has been assessed in prospective studies. We studied 287 men appearing for the medical board prior to medical service and 157 men employed in an industrial company [30]. The dominant echopattern was regular or slightly irregular as seen in 68% of the testes (Fig. 5). A moderately irregular pattern was seen in 28% (Fig. 6), and only 4% of the testes showed a very irregular pattern (Fig. 7) or a pattern with bright echogenic points (Fig. 8). In our studies a testis with microlithiasis was registered as very J Med Ultrasound 2008 Vol 16 No 4 259

5 S. Lenz, A. Giwercman Fig. 4. Testicular tissue with intratubular calicifications (arrows). The calcium bodies are seen inside tubules with normal spermatogenic tissue in this case. This type of microcalcification is more frequently found in testes with carcinoma-in-situ but even in maldescended gonads and those from infertile men. The association between testicular microlithiasis is possible but not well established. Fig. 6. Ultrasound print of longitudinal scan of a testis with a moderately irregular echopattern. This echopattern correlates with reduced sperm quality. The number 3 indicates a score of 3 in the scale of 1 to 4 in irregularity. The bright irregular linings below the testis represents hair and air over the skin of the thigh. Fig. 5. Ultrasound print of a transverse scan of normal testis with a slightly irregular echopattern. The testis is measured between calipers and the rete testis marked by a blue arrow. This is a normal finding by ultrasound. Fig. 7. Ultrasound print of the testis from a patient with previous parotitis which has destroyed the germinative epithelium. The echopattern is very irregular. The inserted Doppler square shows low perfusion and there is no suspicion of cancer. irregular if more than two echogenic points were seen per testis. Peterson et al [31] has also studied men from a military training group. The scanned 1,504 men and found a prevalence of 5% for microlithiasis. Microlithiasis was defined as the presence of more than five high intensive signals per testis. The pattern was nominated scant when 5 25 signals were seen in the testis, moderate when more than 25 were seen, and too numerous to count. von Eckardstein et al [32] studied 198 healthy men with normal sperm count. The authors discerned between less than five echogenic foci per picture, and more than five foci per picture. Three men had a low degree and three had a higher degree. A total of six men had microlithiasis corresponding to a prevalence of 3%. The presence of microlithiasis in an asymptomatic group of men has been studied by Serter et al [33] in a prospective study of 2,179 army trainees. 260 J Med Ultrasound 2008 Vol 16 No 4

6 CIS Testis and Ultrasound Fig. 8. Ultrasound print of a longitudinal scan of a testis with numerous bright echogenic points. The pattern of microlithiasis is not as uniformly distributed as in Fig. 3. The pattern is most intense in the upper and in the lower pole of the testis. The prevalence of microlithiasis in one or both testes was 2.4%. Microlithiasis is thus a rare finding in non selected men. The prevalence is between 2.4% and 5%, depending on the definition. Microlithiasis is furthermore more prevalent than testicular malignancy even in countries like Denmark and Norway where men have a high lifetime risk of TGCC. The inclusion of a very irregular echopattern [30] does not seem to increase the prevalence. The Echopattern in Infertile Men An overview of studies in infertile men is given in Table 1. We studied 95 infertile men by ultrasound and bilateral open biopsies. They were selected if their sperm count < 20 million/ml and if they fulfilled at least one of following criteria; history of maldescensus or orchidometer volume less than 15 ml; or if their sperm count < 10 million/ml [34]. The median echopattern was significantly more irregular than in the non selected group. The very irregular pattern group in our studies included microlithiasis with more than two echogenic foci per testis, but also otherwise severe irregularity of the echopattern. A very irregular echopattern was found in 29% of the testes. None of the biopsies showed CIS. The degree of irregularity was negatively Table 1. Microlithiasis and CIS in infertile men Definition CIS in non Author Publication No. of men Microlithiasis CIS in microlithiasis microlithiasis microlithiasis Lenz et al [34] %* > 2 per testis 0 0 Gouveia-Brazao et al [35] % > 5 per scanning field 20% by bilateral microlithiasis 0.5% 0% by unilateral microlithiasis 1 in 210 Aizenstein et al [36] % > 5 per scanning field No biopsies No biopsies Thomas et al [37] % > 5 per scanning field No biopsies No biopsies von Eckardstein et al [32] ,399 3% Presence in all 16% No biopsies *Including a very irregular pattern; follow up including development of testicular germ cell cancer. J Med Ultrasound 2008 Vol 16 No 4 261

7 S. Lenz, A. Giwercman correlated to spermatogenesis and positively correlated to the number of obliterated tubules. Gouveia-Brazao et al [35] retrospectively studied the association between microlithiasis and CIS in 263 subfertile men. Sperm count was not given in the article. All men were examined by ultrasound and bilateral biopsies. Microlithiasis was defined as five or more hyperechoic foci per transducer field. Fifty three men (20%) had testicular microlithiasis. Twenty three men displayed the pattern in one testis and 30 in both. None of the patients with unilateral microlithiasis had CIS in their biopsies; in contrast, 20% with bilateral microlithiasis were diagnosed with CIS. There was one case diagnosed with CIS among 210 men without microlithiasis (0.5%). Aizenstein et al [36] studied consecutive infertile patients and found a prevalence of microlithiasis of 2.8% when defining microlithiasis by more than five echogenic foci per transducer field in either testis. No testicular biopsies were done. Thomas et al [37] studied 159 consecutive infertile men and found a prevalence for microlithiasis of 6.2%. Microlithiasis was noted if more than five hyperechogenic foci were seen per transducer field. Five had the echopattern in a minimal degree and five in a marked degree. von Eckardstein et al [32] also studied infertile men by ultrasound. They found the same prevalence of microlithiasis as in their group of normal men, namely 3%. Testicular biopsy was performed in 76 out of 1,399 infertile men, and CIS was detected in two, both being atrophic testes with microlithiasis. In one of these patients biopsy had been performed 5 years earlier without revealing CIS. The prevalence of microlithiasis in infertile men is between 2.8% and 29%, probably depending on the definition of infertility and of co-existing diagnoses, and also depending on the definition concerning the degrees of microlithiasis (Table 1). When biopsies were taken, CIS was diagnosed in groups with microlithiasis but very rarely in groups without microlithiasis (0.5%) [35]. The highest prevalence of microlithiasis in infertile men was found by Lenz et al [34] but the authors included testes with a very irregular pattern in the group with microlithiasis. The Echopattern in Cryptorchid Men There is a correlation between microlithiasis and a history of cryptorchidism [35]. We have performed a prospective study of men with a history of cryptorchidism [26]. These men were contacted years after being admitted for cryptorchidism and offered ultrasound of the testes and biopsy of the previously registered maldescended testes. A total of 192 men agreed to have ultrasound and biopsy. Ultrasound was performed of previously non-descended testes. A very irregular pattern or a pattern with microlithiasis was seen in 12 testes (3.2%) of which two testes had descended normally. These two testes were also biopsied. CIS was diagnosed in two testes, both being from the group with a very irregular echopattern. One case of CIS was in one of the normally descended testes which was selected for biopsy due to the ultrasonic pattern. CIS was thus diagnosed in 17% of testes with a very irregular echopattern. The low rate of irregularity in this early study might be explained by the use of a 3.5 MHz probe with near-field focus. The resolution was, thus, not optimal, only higher degrees of irregularity being disclosed. It was the first, prospective study on echopatterns of the testes and CIS, and the results looked promising leading to more prospective studies on the testicular echopattern. The risk of CIS in this study of cryptorchid men was 17% for the group with a very irregular ultrasonic pattern. The Echopattern in the Contralateral Testis in Men with Testicular Cancer The prevalence of CIS in the contralateral testes in men with unilateral testicular cancer seems to be 5% 8% [38 40]. We performed a prospective study of the contralateral testis in men with unilateral testicular cancer [41]. Seventy-eight men had testicular biopsy and ultrasound scanning of the contralateral testis. A very irregular pattern was seen in 50% of the testes. Eight of these were diagnosed with CIS (21%) and a total of nine testes were 262 J Med Ultrasound 2008 Vol 16 No 4

8 CIS Testis and Ultrasound diagnosed with CIS (12%). The last case of CIS was in a testis with a less irregular pattern, and in this testis CIS was only seen in < 10% of the tubules in the biopsy. von Eckardstein et al [32] studied 83 men with unilateral testicular cancer using ultrasound of the contralateral testis. Twenty two (27%) had microcalcifications. Most (14) had more than five per scanning field and the remaining eight had less than five microcalcifications per scanning field. Biopsy data were not given in the article. Holm et al [39] scanned the contralateral testis in 64 men with unilateral testicular cancer and found microcalcifications in nine testes, seven of which harboured CIS, one with early invasive cancer. Six testes with CIS were registered as showing a more regular echopattern. The 78% prevalence of CIS in testes with microcalcifications in this study seems very high. The prevalence of CIS in testes with a normal echopatterns in this study might indicate that the criteria for classifying the ultrasound pattern might differ from those applied by other researchers. Evaluation of echopatterns vary between studies and the prevalence of an irregular pattern or a pattern with microcalcificatios differs accordingly. The risk of CIS in the contralateral testis seems to be 21% 27% for an abnormal echopattern if the study by Holm et al is excluded. The Echopattern Adjacent to a Testicular Cancer As CIS is the precursor of germ cell tumors CIS must be present close to a tumor. It is therefore of interest to look at the echopattern in testes where a testes residue is present. In a prospective study 56 patients were scanned the evening before surgery due to a suspicion of testicular tumors [43]. The ultrasound examination showed tumor or tumor suspicion in 35 cases, and surgery confirmed the diagnosis in 31 cases. The result of ultrasound was not disclosed to the surgeon. There was no cancer in the group where ultrasound did not indicate presence of a tumor. In 24 testis cancer cases the tumor was so small that the echopattern of the testis residue of the affected testis could be evaluated. In all cases a very irregular pattern was seen. Risk of Testis Cancer in Non-selected Patients with Microlithiasis An overview of publications correlating the risk of malignancy in non-selected patients with microlithiasis is given in Table 2. Backus et al [43] retrospectively analyzed 42 consecutive patients with microlithiasis. These patients were admitted for a variable number of scrotal diseases. The number of echogenic foci varied from five to 60 per ultrasound image. Thirteen patients displayed an area of hypoechogenecity and a tumor was confirmed in 11 cases (26%). Skyrme et al [44] retrospectively analyzed 2,215 scrotal scannings on various indications. There were 34 cases with microlithiasis (1.4%), and five had testicular tumors (15%). Derogee et al [45] in a similar study analyzed 1,535 scrotal ultrasound examinations and found that 63 had microcalcifications (4%). In 29 patients a concomitant tumor field was seen (46%), and one patient developed a testicular tumor during follow-up giving a total rate of 48%. Middleton et al [46] performed a prospective study in non-selected patients. Ultrasound was performed in 1,079 men and microcalcifications were noted in 195 (18%). A coexisting tumor was seen in 12 patients (6%). Pourbagher et al [47] studied ultrasound examination for scrotal pathology in 5,263 patients and found microlithiasis in 40 (0.8%). Four patients had a concomitant tumor (10%). Lam et al [48] have retrospectively studied 3,254 sonographic examinations and identified 137 (4%) patients with microlithiasis. Eight (6%) had testicular cancer. Ultrasound of the testes is performed on various indications and microcalcifications will be noted in 1% 18%. This wide span in the prevalence J Med Ultrasound 2008 Vol 16 No 4 263

9 S. Lenz, A. Giwercman Table 2. Microlithiasis and testis cancer prevalence or development Author Year of publication No. of men with microlithiasis No. of men with tumor at examination or later Backus et al [43] (26%) Skyrme et al [44] (15%) Derogee et al [45] (48%) Middleton et al [46] (6%) Pourbagher et al [47] (10%) Lam et al [48] (6%) A B Fig. 9. Original scanning prints from the study of men from the general population (Lenz et al 1993) [30]. These 2 men later developed testicular cancer. (A) A very irregular pattern on a longitudinal scan. (B) Microlithiasis in the lower half of a transverse scan. probably reflects the underlying indication for scanning. When microcalcifications are noted, cancer will be present or else develop in 6% 48%, again probably reflecting the underlying diseases (Table 2). Follow Up of Studies of Non-selected Men with Suspicious Echopattern The 84 men with microlithiasis from the study by Peterson et al [31] entered a follow-up study performed by DeCastro et al [49]. Sixty-three could be contacted after 5 years and one had developed testicular cancer (1.6%). We also performed a follow-up study 5 years after having previously scanned a group of 444 non-selected men. All were cross-tabulated with the Danish Cancer Registry. Testicular cancer was registered in two, one in the group of very the irregular echopatterns and one in the group assigned a lower degree of irregularity. The original images from the latter case were re-evaluated, and it was seen that the echopattern was very irregular and clearly misinterpreted at the time of scanning (Fig. 9A). The 39 men with a very irregular echopattern were contacted and asked to participate in further work-up. Twenty-one agreed to have a biopsy performed and one showed early microinvasion. At least three of the 39 (8%) with very irregular echopatterns later developed testicular malignancy (Lenz, not previously published). Eckardstein et al [32] performed follow-up of their group of healthy 198 volunteers 3 to 5 years after ultrasound evaluation. One case of testis cancer was registered and it was in the group of six men with microlithiasis (17%). 264 J Med Ultrasound 2008 Vol 16 No 4

10 CIS Testis and Ultrasound The Diagnostic Value of Ultrasound Screening and Additional Recommendations In our opinion, there is now a lot of evidence indicating that ultrasound scanning is a valuable diagnostic tool in the detection of CIS of the testis. So far, there seems to be not enough evidence to define those only with bilateral microlithiasis as being at high risk, as proposed by Gouveia-Brazao et al [35]. The sensitivity of detecting CIS is high (estimated > 80%), although the exact magnitude is difficult to calculate due to the scarcity of data on follow-up of testicular biopsies and the heterogeneity of groups being investigated (infertile men, men with history of cryptorchidism, men with unilateral testicular cancer, and non-selected patients). On the other hand, the specificity of finding testicular microlithiasis or a very irregular pattern in relation to the risk of malignancy is rather low since only one in five having suspicious echo patterns will develop cancer. The degree of microlithiasis correlates with a risk of CIS, and should therefore be described together with this evaluation to assist clinical decision making. We propose that all men coming for andrological examination due to infertility problems, cryptorchidism, and scrotal problems should undergone testicular ultrasound and the identification of microlithiasis or a very irregular pattern should lead to referral for testicular biopsy in order to search for CIS. Nevertheless, large follow-up studies of men from the general population are needed in order to find out whether this can be recommended as a general screening method. How to Perform a Scanning of the Testes Ultrasound scanning of the testes is an easy and rapid procedure which can be a part of a routine andrological examination or used as a screening procedure to detect focal tumors in a patient with an increased risk of CIS. Fig. 10. Color Doppler shows the vessels inside the testis radiating from the rete testis. The rete testis is marked by a blue arrow. A bigger artery is seen outside the testis in the epididymis (red). Fig. 11. Cancer lesion noticed as a 6 mm hypoechogenic structure inside the testis (green arrow). The testis residue displays a moderate degree of microlithiasis (blue arrows). The man is placed in the supine position. The penis is held upward and covered by a towel. With the legs placed close together the scrotum is presented in a firm position for scanning. Use a nearfield probe with a frequency of MHz, covered by a thin plastic bag, and place it directly at the scrotum. Ultrasound gel should be applied inside and outside the bag. Each side is scanned separately. The testis is measured in three dimensions and the scanner s volume calculator is used to calculate the volume. The normal volume for the right testis is 14 ml, and for the left testis 13 ml. Lower volumes always indicate impaired testicular function. The echopattern of the testes should be evaluated, J Med Ultrasound 2008 Vol 16 No 4 265

11 S. Lenz, A. Giwercman the normal pattern being slightly irregular. A very irregular pattern or the presence of bright echogenic points should be registered as an abnormal finding. Perform a grading of these microcalcifications when seen. The rete testis is seen laterally as an echogenic lining along the testis (Fig. 5). Vessels are seen radiating from it and into the testicular tissue separating the lobuli (Fig. 10). Tumors appear hypoechogenic (Fig. 11). They can be detected from a size of 4 mm in diameter and will be malignant in 95% of cases [50]. Acknowledgments We would like to thank Ms. Nishtman Dizeyi for help with preparing the histological images. References 1. Richiardi L, Bellocco R, Adami HO, et al. Testicular cancer incidence in eight northern European countries: secular and recent trends. Cancer Epidemiol Biomarkers Prev 2004;13: Shah MN, Devesa SS, Zhu K, et al. Trends in testicular germ cell tumours by ethnic group in the United States. Int J Androl 2007;30: Giwercman A, Rylander L, Hagmar L, et al. Ethnic differences in occurrence of TDS genetics and/or environment? Int J Androl 2006;29: Skakkebæk NE, Rajpert-De Meyts E, Main KM. Testicular dysgenesis syndrome: an increasingly common developmental disorder with environmental aspects. Hum Reprod 2001;16: Hemminki K, Li X. Cancer risks in Nordic immigrants and their offspring in Sweden. Eur J Cancer 2002;38: Hemminki K, Li X. Cancer risks in second-generation immigrants to Sweden. Int J Cancer 2002;99: Hemminki K, Li X, Czene K. Cancer risks in firstgeneration immigrants to Sweden. Int J Cancer 2002; 99: Hemminki K, Chen B. Familial risks in testicular cancer as aetiological clues. Int J Androl 2006;29: Skakkebæk NE. Possible carcinoma-in-situ of the testis. Lancet 1972;ii: Skakkebæk NE. Carcinoma in situ of the testis: frequency and relationship to invasive germ cell tumours in infertile men. Histopathology 1978;2: Skakkebæk NE, Berthelsen JG, Giwercman A, et al. Carcinoma-in-situ of the testis: possible origin from gonocytes and precursor of all types of germ cell tumours except spermatocytoma. Int J Androl 1987; 10: Giwercman A, Berthelsen JG, Müller J, et al. Screening for carcinoma-in-situ of the testis. Int J Androl 1987; 10: Almstrup K, Hoei-Hansen CE, Wirkner U, et al. Embryonic stem cell-like features of testicular carcinoma in situ revealed by genome-wide gene expression profiling. Cancer Res 2004;64: Rajpert-De Meyts E, Skakkebæk NE. The possible role of sex hormones in the development of testicular cancer. Eur Urol 1993;23: von der Maase H, Giwercman A, Müller J, et al. Management of carcinoma-in-situ of the testis. Int J Androl 1987;10: Giwercman A. Editorial Comment on: Non-invasive detection of testicular carcinoma in situ in semen using OCT3/4. Eur Urol 2008;54: Giwercman A. Carcinoma-in-situ of the testis: screening and management. Scand J Urol Nephrol 1992;148 (suppl): Hoei-Hansen CE, Carlsen E, Jorgensen N, et al. Towards a non-invasive method for early detection of testicular neoplasia in semen samples by identification of fetal germ cell-specific markers. Hum Reprod 2007;22: van Castern N, Stoop H, Dohle GR, de Wit R, Oosterhuis JW, Looijenga LHJ. Non-invasive detection of testicular Carcinoma in situ in semen using OCT3/4. Eur Urol 2007 [In press]. 20. Giwercman A, Clausen OPF, Skakkebæk NE. Carcinoma in situ of the testis: aneuploid cells in semen. B Med J 1988;296: Giwercman A, Hopman AHN, Ramaekers FCS, et al. Carcinoma in situ of the testis. Detection of malignant germ cells in seminal fluid by means of in situ hybridization. Am J Pathol 1990;136: Bruun E, Frimodt-Møller C, Giwercman A, et al. Testicular biopsy as an outpatient procedure in screening for carcinoma-in-situ: complications and the patient s acceptance. Int J Androl 1987;10: Dieckmann KP, Loy V. False-negative biopsies for the diagnosis of testicular intraepithelial neoplasia (TIN) an update. Eur Urol 2003;43: J Med Ultrasound 2008 Vol 16 No 4

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