Classic Testicular Microlithiasis Research Articles

Spurious Self-Suppression Method: Application to TM Cavity Filters

This article presents a new approach for improving spurious free bands in filters. The main idea is to control the coupling coefficients of the spurious resonances, in order to force them to cancel each other. This approach is completely different from the classical one where all couplings are minimized in order to excite spurious resonances as less as possible. In fact, in this approach, all spurious couplings are maximized except the central coupling that is instead minimized. This method is first explained in terms of equivalent circuits. Then, in order to show its applicability to real microwave filters, it is applied to the TM cavity filters and used to remove both spurious resonances due to higher order cavity modes and to TE10 mode of coupling irises. Design examples of fourth- and sixth-order TM cavity filters are presented. With respect to the classical TM cavity filter, where the first spurious appears around 11.4 GHz, the TM filters designed by exploiting the self-suppression method present spurious free bands up to 20.2 GHz (20 GHz for sixth-order filter), improving the filter response up to 2.2 times the center frequency of 9.2 GHz. Another advantage is that, in contrast to the classical spurious suppression method that does not allow responses with TZs in TM filters, the self-suppression method allows for a number of TZs equal to N-2 (N being the filter order) and it also allows a certain control of their position.

Dielectric TM-Mode Y-Shaped Doublet Structure

This paper discusses dielectric TM-mode filters based on high permittivity Y-shaped ceramics. It is shown that this type of ceramic operates as a dual-mode resonator and therefore contributes two reflection zeros as well as one transmission zero (TZ) to the filter response. Hence, it can be interpreted as a doublet structure and used for the realization of quasi-elliptical filter responses of different order. The dual-mode resonator can be used in multiple different filter set-ups: On the one hand, a combination with classical TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{010}$</tex-math></inline-formula> -mode resonators is possible to allow the realization of TZs in an in-line filter configuration without using cross-coupling apertures. Therefore, negative or diagonal cross-couplings, which are often difficult to realize and handle, can be avoided. On the other hand, several Y-shaped ceramics can be coupled directly with each other to increase the number of TZs to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$n_{fz}=n/2$</tex-math></inline-formula> , where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$n$</tex-math></inline-formula> is the order of the filter. Finally, it is shown that even a combination with extracted pole elements is realizable. Prototypes based on modular segments are manufactured as proof of concept.

High-precision GNSS PWV retrieval using dense GNSS sites and in-situ meteorological observations for the evaluation of MERRA-2 and ERA5 reanalysis products over China

Precipitable water vapor (PWV) product with high accuracy and high spatiotemporal resolution is important for climate change research. Hourly PWV products with a high spatiotemporal resolution can be provided by global navigation satellite system (GNSS) and global reanalysis data. The National Aeronautics and Space Administration (NASA) and the European Center for Medium-Range Weather Forecasts (ECMWF) have recently released their global reanalysis of the Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) and the fifth-generation ECMWF Reanalysis (ERA5), respectively. A comprehensive evaluation of these two PWV reanalysis products over China has yet to be fully investigated. In this study, the PWV products of MERRA-2 and ERA5 reanalysis over China have been systematically evaluated based on 339 GNSS sites and in-situ ground meteorological observations from year 2016 to 2018. To mitigate the uncertainties of this evaluation, three enhanced vertical correction models for temperature, pressure and PWV that we developed previously are adopted. Four weighted mean temperature (Tm) models are established for the four regions of China (North China, South China, Tibet Plateau, and Northwest China), and they exhibit better accuracy than the other classical Tm models in China. The evaluation results of the MERRA-2- and ERA5-derived PWV show that the correlation coefficient, biases, and root mean square error (RMSE) in China are 0.98/0.99, −0.51/0.38 mm, and 2.50/1.99 mm, respectively. They both exhibit relatively large difference when applied to South China. For the same grid spatial resolution, ERA5 PWV product exhibits similar performance with MERRA-2. The monthly-mean-reanalysis-derived PWV exhibits obvious seasonality and has the largest difference in summer. ERA5 PWV can provide more details of the spatial pattern compared to MERRA-2 PWV. The diurnal anomaly variation for ERA5 is more consistent with GNSS data, and some differences at certain moments during autumn and winter have been observed. These results show that ERA5 PWV and MERRA-2 PWV exhibits excellent applicability in China and can help us to efficiently use PWV products for climate research in China.

Fluorescence-Based Binding Characterization of Small Molecule Ligands Targeting CUG RNA Repeats.

Pathogenic CUG and CCUG RNA repeats have been associated with myotonic dystrophy type 1 and 2 (DM1 and DM2), respectively. Identifying small molecules that can bind these RNA repeats is of great significance to develop potential therapeutics to treat these neurodegenerative diseases. Some studies have shown that aminoglycosides and their derivatives could work as potential lead compounds targeting these RNA repeats. In this work, sisomicin, previously known to bind HIV-1 TAR, is investigated as a possible ligand for CUG RNA repeats. We designed a novel fluorescence-labeled RNA sequence of r(CUG)10 to mimic cellular RNA repeats and improve the detecting sensitivity. The interaction of sisomicin with CUG RNA repeats is characterized by the change of fluorescent signal, which is initially minimized by covalently incorporating the fluorescein into the RNA bases and later increased upon ligand binding. The results show that sisomicin can bind and stabilize the folded RNA structure. We demonstrate that this new fluorescence-based binding characterization assay is consistent with the classic UV Tm technique, indicating its feasibility for high-throughput screening of ligand-RNA binding interactions and wide applications to measure the thermodynamic parameters in addition to binding constants and kinetics when probing such interactions.

Attenuation of waveguide modes in narrow metal capillaries.

The channeling of laser pulses in waveguides filled with a rare plasma is one of the promising techniques of laser wakefield acceleration. A solid-state capillary can precisely guide tightly focused pulses. Regardless of the material of the capillary, its walls behave like a plasma under the influence of a high-intensity laser pulse. Therefore, the waveguide modes in the capillaries have a universal structure, which depends only on the shape of the cross-section. Due to the large ratio of the capillary radius to the laser wavelength, the modes in circular capillaries differ from classical TE and TM modes. We consider the structure of capillary modes in a circular capillary, calculate the attenuation rates, discuss the mode expansion of the incident pulse using minimal simplifications, and analyze the accuracy of commonly used approximations. The attenuation length for such modes is two orders of magnitude longer than that obtained from the classical formula, and the incident pulse of the proper radius can transfer up to 98% of its initial energy to the fundamental mode. However, finding eigenmodes in capillaries of arbitrary cross-sections is a complex mathematical problem that remains to be solved.

Testicular microlithiasis in male infertility: prevalence, diagnosis and treatment algorithm

Aim of study. To estimate testicular microlithiasis (TM) prevalence in men seeking help for infertility in reproductive medicine center, and generate an algorithm for TM management according to patients choice to perform testicular biopsy or not.&#x0D; Materials and methods. We retrospectively reviewed charts of 143 consecutive adult male patients between 19 and 73 years (mean age 34.6 7.9) seeking help for infertility in International Center for Reproductive Medicine. Gray-scale and color Doppler were used to calculate testicular volume and to study a spectrum of scrotal disorders including testicular microlithiasis.&#x0D; Results. Testicular size varied from 0.5 to 33.3 ml (mean 12.3 5.8 ml), testicular hypoplasia, varicocele, hydrocele and epididymal cysts were detected in 88 (61.5%), 35 (24.5%), 9 (6.3%) and 50 (35%) patients respectively. TM signs were identified in 12 (8.4%) men, including 5 (42%) cases of classic TM and 7 (58%) cases of limited TM; 5 (42%) men had bilateral TM. One 1 (8%) patient with bilateral ТМ had ultrasonic appearance of non-palpable testicular tumor, radical surgical treatment was performed. Patients with TM had smaller testicles, higher prevalence of azoospermia and testicular tumor (p = 0.002, 0.013 and 0.085 respectively). All patients with TM were informed about their risks to harbor testicular cancer and taught self-examination technique. Testicular biopsy was offered to all men with concomitant risk factors for testicular cancer development, however none of the patients agreed. We have consequently developed algorithm for TM management according to patients choice to perform or to avoid testicular biopsy.&#x0D; Conclusion. ТМ is common in infertile men, scrotum ultrasound is indicated to detect it. The suggested algorithm for TM management is aimed towards early testicular cancer detection and successful treatment with fertility potential preservation.

Incidence characteristics of testicular microlithiasis and its association with risk of primary testicular tumors in children: a systematic review and meta-analysis.

To systematically evaluate the incidence characteristics of testicular microlithiasis (TM) in children and its association with primary testicular tumors (PTT). A systematic review and meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. A priori protocol was registered in the PROSPERO database (CRD42018111119), and a literature search of all relevant studies published until February 2019 was performed. Prospective, retrospective cohort, or cross-sectional studies containing ultrasonography (US) data on the incidence of TM or the association between TM and PTT were eligible for inclusion. Of the 102 identified articles, 18 studies involving 58,195 children were included in the final analysis. The overall incidence of TM in children with additional risk factors for PTT was 2.7%. In children, the proportion of left TM in unilateral cases was 55.7%, the frequency of bilateral TM was 69.0%, and proportion of classic TM was 71.8% [95% confidence interval (CI) 62.4-81.1%, P = 0.0, I2 = 0.0%]. About 93.5% of TM remained unchanged, and newly detected PTT rate was very low (4/296) during follow-up. The overall risk ratio of TM in children with a concurrent diagnosis of PTT was 15.46 (95% CI 6.93-34.47, P < 0.00001). The incidence of TM in children is highly variable. Nonetheless, TM is usually bilateral, of the classic type, and remains stable or unchanged at follow-up. Pediatric patients with TM and contributing factors for PTT have an increased risk for PTT; however, there is no evidence to support mandatory US surveillance of children with TM.

Prevalence and risk factors of testicular microlithiasis in patients with hypospadias: a retrospective study

BackgroundIt has been described that the incidence of testicular microlithiasis is high in several congenital disorders which may be associated with testicular impairment and infertility. Several reports have shown that a prepubertal or pubertal hormonal abnormality in the pituitary-gonadal axis was identified in some patients with hypospadias that is one of the most common disorders of sex development. However, exact prevalence or risk factors of testicular microlithiasis in patients with hypospadias have not reported so far. In the present study, to clarify the prevalence and risk factors of testicular microlithiasis in patients with hypospadias, a retrospective chart review was performed.MethodsChildren with hypospadias who underwent testicular ultrasonography between January 2010 and April 2016 were enrolled in the present study. Severity of hypospadias was divided into mild and severe. The prevalence and risk factors of testicular microlithiasis or classic testicular microlithiasis were examined.ResultsOf 121 children, mild and severe hypospadias were identified in 66 and 55, respectively. Sixteen children had undescended testis. Median age at ultrasonography evaluation was 1.7 years old. Testicular microlithiasis and classic testicular microlithiasis were documented in 17 children (14.0%) and 8 (6.6%), respectively. Logistic regression analysis revealed that presence of undescended testis was only a significant factor for testicular microlithiasis and classic testicular microlithiasis. The prevalence of testicular microlithiasis or classic testicular microlithiasis was significantly higher in children with undescended testis compared to those without undescended testis (testicular microlithiasis; 43.8% versus 9.5% (p = 0.002), classic testicular microlithiasis; 37.5% versus 1.9% (p < 0.001).ConclusionsThe current study demonstrated that the presence of undescended testis was only a significant risk factor for testicular microlithiasis or classic testicular microlithiasis in patients with hypospadias. As co-existing undescended testis has been reported as a risk factor for testicular dysfunction among patients with hypospadias, the current findings suggest that testicular microlithiasis in children with hypospadias may be associated with impaired testicular function. Conversely, patients with isolated HS seem to have lower risks for testicular impairment. Further investigation with longer follow-up will be needed to clarify these findings.

Adolescent testicular microlithiasis: A case-based, multinational survey of clinical management practices

Testicular microlithiasis (TM) is a condition characterized by calcium deposits within the testis, usually detected incidentally during ultrasonography of the scrotum. TM has been associated with the presence of, and possibly the development of, testicular malignancy. Our aim was to document international clinical management practices for TM and to analyze what factors and perception of risk influence conservative versus active management and follow-up. European Society for Paediatric Urology (ESPU) and Society for Pediatric Urology (SPU) members were invited to complete an online case-based survey of clinical management practices of TM. Eight cases had a single variable changed each time (classic versus limited TM, unilateral versus bilateral, prior cryptorchidism versus no cryptorchidism) to ascertain the provider's perception of risk. The respondents completed multiple choice questions on initial management, follow-up plan, length and interval of follow-up. Multivariate logistic regression was performed to determine factors associated with decisions on management and follow-up. There were 265 respondents to the survey from 35 countries (Table). Median time in practice was 13 years. Factors that were significantly associated with more aggressive initial management (more than counseling on self-examination) included: not yet in independent practice, low volume TM cases per year, those practicing pediatric and adult urology, classic appearance of TM and cryptorchidism. Factors that were significantly associated with urologist follow-up and active investigation included: European practitioners, low TM case volume per year, those practicing both pediatric urology and pediatric surgery, classic TM appearance and a case history of cryptorchidism. Interval and length of follow-up was wide-ranging, with most respondents favoring annual follow-up. Management of TM varies and a mix of surgeon and case factors significantly influences management strategies. This baseline understanding of the lack of systematic management suggests the need for the development of consensus guidelines and prospective study.

Prevalence and Chronological Changes of Testicular Microlithiasis in Isolated Congenital Undescended Testes Operated On at Less Than 3 Years of Age

To clarify the prevalence and chronological changes of testicular microlithiasis in isolated congenital undescended testes, retrospective chart review was performed. Among children with palpable isolated undescended testes who underwent orchiopexy at less than 3 years of age between January 2009 and May 2016, those who had preoperative testicular ultrasonography were enrolled. Testicular microlithiasis was classified as limited or classic. Sixty-five patients (54 unilateral undescended testes and 11 bilateral undescended testes) were enrolled. Preoperative evaluation demonstrated limited testicular microlithiasis in only 2 undescended testes in 2 patients (1 with unilateral undescended testes and 1 with bilateral undescended testes). Of these patients, 1 with unilateral undescended testes had limited testicular microlithiasis and the other with bilateral undescended testes had classic testicular microlithiasis after surgery. Among 53 unilateral undescended testes without microlithiasis preoperatively, limited and classic testicular microlithiasis was found in 1 and 6 testes, respectively, during follow-up. Testicular microlithiasis was identified in 2 on the contralateral descended testis of unilateral undescended testes postoperatively. Among 10 patients with bilateral undescended testes without microlithiasis preoperatively, limited testicular microlithiasis was detected in 4 during follow-up. Testicular microlithiasis was not diminished or resolved during follow-up. The overall prevalence of testicular microlithiasis in undescended testes (21.1%) was significantly higher than that in the contralateral descended testis in patients with unilateral undescended testes (3.7%) (P < .01). Most testicular microlithiasis was identified postoperatively and never improved. The prevalence of testicular microlithiasis in isolated congenital undescended testes increased with time even if operated on early in life.

MP66-14 TESTICULAR MICROLITHIASIS: A CASE-BASED, MULTINATIONAL SURVEY OF CLINICAL MANAGEMENT PRACTICES

INTRODUCTION Testicular microlithiasis (TM) is a condition characterized by calcium deposits within the testis, usually detected incidentally during ultrasonography of the scrotum. TM has been associated with the presence of, and possibly the development of, testicular malignancy. Our aim was to document international clinical management practices for TM and to analyze what factors and perception of risk influence conservative versus active management and follow-up. METHODS European Society for Paediatric Urology (ESPU) and Society for Pediatric Urology (SPU) members were invited to complete an online case-based survey of clinical management practices of TM. Eight cases had a single variable changed each time (classic versus limited TM, unilateral versus bilateral, prior cryptorchidism versus no cryptorchidism) to ascertain the provider's perception of risk. The respondents completed multiple choice questions on initial management, follow-up plan, length and interval of follow-up. Multivariate logistic regression was performed to determine factors associated with decisions on management and follow-up. RESULTS There were 265 respondents to the survey from 35 countries (Table). Median time in practice was 13 years. Factors that were significantly associated with more aggressive initial management (more than counseling on self-examination) included: not yet in independent practice, low volume TM cases per year, those practicing pediatric and adult urology, classic appearance of TM and cryptorchidism. Factors that were significantly associated with urologist follow-up and active investigation included: European practitioners, low TM case volume per year, those practicing both pediatric urology and pediatric surgery, classic TM appearance and a case history of cryptorchidism. Interval and length of follow-up was wide-ranging, with most respondents favoring annual follow-up. CONCLUSION Management of TM varies and a mix of surgeon and case factors significantly influences management strategies. This baseline understanding of the lack of systematic management suggests the need for the development of consensus guidelines and prospective study.

The influence of testicular microlithiasis on the outcomes of in vitro fertilisation in a Chinese Han population.

To investigate the influence of testicular microlithiasis (TM) on the outcomes of in vitro fertilisation (IVF), we retrospectively reviewed the ultrasonography results of the TM patients who underwent IVF treatment in our hospital. They were classified as classic-TM(CTM) or limited-TM (LTM) comparing with patients without TM (Non-TM). Semen parameters, rates of fertilisation, normal fertilisation, good embryos and clinical pregnancy were analysed. The Non-TM group showed higher percentage of morphologically normal spermatozoa than the CTM or LTM group (4.08±2.07 versus 3.40±2.00 versus 3.04±1.66, p=.003) while the other general semen parameters were comparable. The LTM group showed higher rate of fertilisation than the CTM group (85.10% versus 81.12%, p=.044). Moreover, the rates of normal fertilisation of Non-TM (62.47%) and LTM (66.32%) group were significantly higher than the CTM (58.02%) group (p=.027 and p=.001 respectively). There were 333 embryo transfer cycles in total (including 222 fresh and 111 frozen). The overall clinical pregnancy rate was 54.95%, 58.33% and 64.12% in the group of CTM, LTM and Non-TM respectively. However, no statistically significant difference was obtained (p=.326). Our results suggest that TM may have influence on the IVF outcomes. The extent of microlithiasis correlates inversely with the rates of fertilisation and normal fertilisation.

The Association Between Testicular Microlithiasis and Semen Parameters in Chinese Adult Men With Fertility Intention: Experience of 226 Cases

To investigate the association between testicular microlithiasis (TM) and semen parameters in Chinese adult men with fertility intention. We retrospectively reviewed the ultrasonography results of the reproductive system of 16,204 consecutive adult male patients in our hospital with fertility intention from November 2012 to October 2013. TM was diagnosed by scrotal ultrasonography. Patients with TM were divided into classic testicular microlithiasis (CTM) or limited testicular microlithiasis (LTM). The clinical data of CTM, LTM, and non-TM groups, especially of patients in whom sperms were found in semen analysis, were collected and analyzed. There were 226 men (1.39%) diagnosed with TM. The mean age was 28.96 ± 5.12 years (range, 21-46 years), whereas mean testicular volume was 15.38 ± 4.90 mL (range, 1.62-31.23 mL). CTM and LTM were detected in 141 (62.39%) and 85 patients (37.61%), respectively. Among 200 patients who underwent semen analysis, sperms were found in 159 men (79.5%; 97 men with CTM and 62 men with LTM). One hundred and twenty cases without TM (ie, non-TM group) were collected in the control group. Sperm concentration, total motility, and percentage of progressively motile of CTM, LTM, and non-TM groups was (38.01 ± 31.58 million/mL vs 52.31 ± 33.26 million/mL vs 67.16 ± 36.94 million/mL; P <.001), (46.03 ± 23.69% vs 55.37 ± 24.16% vs 62.08 ± 20.45%; P <.001), and (35.88 ± 20.17% vs 43.15 ± 21.08% vs 47.10 ± 17.84%; P <.001), respectively. TM is associated with worse semen parameters in adult men with fertility intention. The extent of microlithiasis correlates inversely with semen parameters.

Combination of squared correlators for multipath mitigation in safety-of-life global navigation satellite systems receivers

This study presents a novel solution of DLL discrimination function for multiband global navigation satellite systems (GNSS) receivers, designed to cope with a multipath-prone environment in safety-of-life (SoL) applications. The solution is based on a combination of squared correlators (CSC) outputs, following an approach similar to that driving to the well-known, and patented, Strobe TM discriminator. The proposed CSC discriminator features the novelty with respect to other `double-delta` architectures, usually covered by patents, still maintaining a light implementation (four correlators per channel, plus the prompt one); this comes at the cost of sub-optimal performance with respect to the classic Strobe TM discriminator. The study presents the definition of the CSC solution in the context of a SoL receiver architecture, discusses the motivations for its design choices and shows an analysis of performance both in open-loop, basically employing the discriminator S -curve and the multipath error envelope, and in closed-loop, measuring the variance of estimated code phase and the statistics of the multipath-induced phase error. Performance of the proposed function are evaluated for the typical modulations of the GPS L 1 and Galileo E 1 systems, namely BPSK(1), BOC(1,1) and CBOC(6,1,1/11).

Theoretical Study of Negatively Charged Fe––(H2O)n ≤ 6 Clusters

Interactions of a singly negatively charged iron atom with water molecules, Fe(-)-(H(2)O)(n≤6), in the gas phase were studied by means of density functional theory. All-electron calculations were performed using the B3LYP functional and the 6-311++G(2d,2p) basis set for the Fe, O, and H atoms. In the lowest total energy states of Fe(-)-(H(2)O)(n), the metal-hydrogen bonding is stronger than the metal-oxygen one, producing low-symmetry structures because the water molecules are directly attached to the metal by basically one of their hydrogen atoms, whereas the other ones are involved in a network of hydrogen bonds, which together with the Fe(δ-)-H(δ+) bonding accounts for the nascent hydration of the Fe(-) anion. For Fe(-)-(H(2)O)(3≤n), three-, four-, five-, and six-membered rings of water molecules are bonded to the metal, which is located at the surface of the cluster in such a way as to reduce the repulsion with the oxygen atoms. Nevertheless, internal isomers appear also, lying less than 3 or 5 kcal/mol for n = 2-3 or n = 4-6. These results are in contrast with those of classical TM(+)-(H(2)O)(n) complexes, where the direct TM(+)-O bonding usually produces high symmetry structures with the metal defining the center of the complex. They show also that the Fe(-) anions, as the TM(+) ions, have great capability for the adsorption of water molecules, forming Fe(-)-(H(2)O)(n) structures stabilized by Fe(δ-)-H(δ+) and H-bond interactions.

Testicular microlithiasis: analysis of prevalence and associated testicular cancer in central-eastern Sicilian andrological patients

The aim of this retrospective study was to determine the prevalence of testicular microlithiasis (TM) in central-eastern Sicilian men and to evaluate the association between TM and testicular tumour or infertility. A total of 1056 Sicilian patients underwent scrotal US between 2005 and 2010. TM was found in 106 men with an overall prevalence of 10%; roughly about four times the median prevalence reported in the previous studies (0.6-18.1%). Forty men (3.8%) had a classic TM, whereas 66 (6.2%) had a limited TM. The prevalence of testicular tumour in this cohort was 2.4% (25/1056). At the moment when the testicular tumour was diagnosed, 15 patients (60%) had TM. There was a significant difference (P < 0.01) between the rate of malignancy in men with TM (15/106; 14.2%) and that in men without TM (10/950; 1.1%) with an odds ratio = 16. The prevalence of TM among infertile patients was 18.8%. These data may relate to an increased awareness towards scrotal US examination and/or to the use of more sensitive equipments. The elevated rate of testicular malignancy in men with TM suggests that this US feature may be regarded as a risk factor for testicular tumour.

Testicular microlithiasis: Analysis of prevalence and associated testicular cancer in Taiwanese men

To determine the incidence of testicular microlithiasis (TM) in Taiwanese males who were referred for scrotal sonography (US) and to evaluate the association between TM and cancer, with state-of-the-art equipment. This retrospective study included 513 males who underwent scrotal US in a period of 7 months. The US images and charts of each patient were reviewed to determine the presence of TM and note relevant clinical information. The data for all 513 patients were analyzed. Their age was 0-91 years (mean, 54.3 years). The overall incidence of TM was 14.4% (74/513); 6.2% (32/513) had classic TM, and 8.2% had limited TM. The incidence of testicular cancer in this population was 1.6% (8/513). Six of eight (75%) patients who had testicular cancer at presentation had classic TM or limited TM. There was a significant difference (P < 0.01) between the rate of malignancy in subjects with TM (6/74) and that in subjects without TM (2/439). The incidence of TM in Taiwanese people may be higher than previously reported, which may be due to the difference in methodology and increased awareness of the US findings. Although there was a significant difference in the rate of malignancy in males with TM compared with those without TM, the question remains whether TM independently increases the risk of testicular malignancy.

Testicular Microlithiasis in Boys and Young Men With Congenital or Acquired Undescended (Ascending) Testis

We assessed the prevalence of testicular microlithiasis by ultrasound in boys and young men with congenital or acquired undescended (ascending) testis. During followup for testicular growth patients with congenital or acquired undescended (ascending) testis were also screened by ultrasound for testicular microlithiasis, which was defined as echogenic foci without shadowing within the testis parenchyma. Classic microlithiasis was defined as 5 or more echogenic foci in either or both testes and limited microlithiasis as fewer than 5 foci. We performed 181 ultrasounds in 181 patients (199 congenital undescended testes) with a mean age of 12.6 years (range 2.6 to 28.6) and 636 ultrasounds in 320 patients (350 acquired undescended/ascending testes) with a mean age of 12.4 years (4.1 to 24.1). Age in both patient groups was equivalent. Median followup was 1.34 years (range 0 to 3.2). Testicular microlithiasis was found in 14 patients (2.8%), of whom 11 (2.2%) displayed classic testicular microlithiasis and 3 (0.6%) exhibited limited testicular microlithiasis. Among these 14 patients 5 had congenital undescended testes, which demonstrated classic microlithiasis. Of these 5 patients 4 had chromosomal deformities. The remaining 9 patients had acquired undescended (ascending) testis, which exhibited classic microlithiasis in 6 instances and limited microlithiasis in 3. The prevalence of testicular microlithiasis in patients with undescended testis is 2.8%. There is no difference in the prevalence of testicular microlithiasis between congenital and acquired undescended (ascending) testes.

Prevalence of Testicular Microlithiasis in Asymptomatic Males 0 to 19 Years Old

We assessed the prevalence of testicular microlithiasis via ultrasound in asymptomatic males 0 to 19 years old. We studied only patients with 2 scrotal testes at birth and at examination. We excluded boys with a history of undescended testis, hydrocele, varicocele and syndromes associated with testicular microlithiasis. To assess for testicular microlithiasis, we scanned the scrotum ultrasonographically by recording transverse and longitudinal images of each testis. Classic testicular microlithiasis was defined as 5 or more echogenic foci in either or both testes. Boys with fewer than 5 microliths (but with at least 1) were deemed to have limited testicular microlithiasis. We examined 694 asymptomatic boys between October 2007 and July 2008, of whom 670 participated in the study. Classic testicular microlithiasis was present in 16 boys (2.4%) and limited testicular microlithiasis in 12 (1.8%), yielding a total prevalence of 4.2%. Classic testicular microlithiasis was found in 1 patient younger than 6 years, 8 boys 6 to 12 years old and 7 boys older than 12 years. There was a significant difference in prevalence among the 3 age groups (p = 0.032). Testicular malignancies were not found in any patient. Of the 24 boys excluded from the study testicular microlithiasis was seen in 4. The prevalence of classic testicular microlithiasis in asymptomatic boys is 2.4% and increases with age.

Increased prevalence of testicular microlithiasis in men with familial testicular cancer and their relatives.

Testicular germ cell tumours (TGCT) cluster in families, but responsible genes remain unidentified. The association between testicular microlithiasis (TM) and testicular carcinoma in situ (CIS) suggests that TM may be a TC risk factor. We report testicular ultrasound findings in men with familial TGCT (FTGCT) and their unaffected relatives. A total of 81 men (48 affected and 33 unaffected) from 31 families with ⩾2 TC cases underwent testicular ultrasound. Testicular microlithiasis was defined as either ‘classic’ (⩾5 microliths) or ‘limited’ (<5 microliths). Statistical analyses used Fisher's exact test and permutation testing. Testicular microlithiasis was more frequent in the contralateral testicles of men with a history of TGCT (affected men) than in unaffected men (48 vs 24%, P=0.04). The association appeared stronger for classic TM (21 vs 9%) than for limited TM (27 vs 15%). Testicular microlithiases were bilateral in six out of seven (87%) unaffected men. Among affected men, TM was not associated with histology, age at diagnosis or cancer treatment. Of the 31 families, 10 accounted for a majority (61%) of the TM cases identified (P=0.11). Testicular microlithiasis was more prevalent among FTGCT family members than described previously in the general population, and was more common among FTGCT cases vs unaffected blood relatives. Testicular microlithiasis appeared to cluster in certain families. These findings suggest both a familial predisposition to TM and an association between TM and FTGCT. If proven, this could be clinically important to men in FTGCT families, and may be useful in identifying specific genes involved in FTGCT.