Testicular microlithiasis: recent advances in understanding and management

Isolated 17, 20 Lyase Deficiency Secondary to a Novel CYB5A Variant: Comparison of Steroid Metabolomic Findings with Published Cases Provides Diagnostic Guidelines and Greater Insight into Its Biological Role

OBJECTIVE

The objective of this study was to report CYB5A deficiency, to discuss the contribution of steroid metabolomics to diagnosis and interpretation, and to highlight the presence of testicular microlithiasis.

METHODS

Two siblings with ambiguous genitalia at birth were later found to carry novel CYB5A variants, with resulting isolated 17, 20 lyase deficiency. We compared urine steroid data obtained between birth and adulthood with that from other cases.

RESULTS

Neonatal urine steroid profiles show a relative increase of 16-hydroxylated pregnenolone metabolites. Thereafter, there are no distinguishing features until puberty, when sex steroid deficiency drives gonadotrophin production, resulting in marked increases of 17-hydroxyprogesterone metabolites derived from the gonads. This excess may be revealed pre-pubertally by gonadotrophin stimulation testing. Novel findings are first, a considerable capacity for DHEA synthesis in the neonatal period compared to childhood and adulthood, suggesting that DHEAS production is much less dependent on CYB5A at birth; second, no consistent change in "backdoor pathway" intermediates; third, side chain cleavage of cortisol is largely unaffected, supporting the existence of a different lyase not dependent on CYB5A; fourth, increased 17-hydroxyprogesterone metabolites and very low androgen metabolites are diagnostic post-pubertally.

CONCLUSION

This is the fourth disease-causing variant in CYB5A in isolated 17, 20 lyase deficiency and the first associated with testicular microlithiasis. Establishing a biochemical diagnosis pre-pubertally should now be possible using urine steroid profiling, supported by synacthen and gonadotrophin stimulation testing. We recommend liquid chromatography-mass spectrometry/mass spectrometry rather than immunoassay for serum steroid analysis, early methaemoglobin measurement and surveillance should testicular microlithiasis be detected.

Testicular microlithiasis defines a subgroup of azoospermic men with low rates of sperm retrieval

OBJECTIVE

To investigate the prevalence of testicular microlithiasis and its association with sperm retrieval rates and histopathology in men with non-obstructive azoospermia.

METHODS

A total of 120 men underwent scrotal ultrasonography prior to microsurgical testicular sperm extraction. Sperm retrieval rate, testicular histopathology, testicular size, reproductive hormones, karyotyping, Y chromosome microdeletion analyses, and presence of varicoceles and hydroceles were compared between men with and without testicular microlithiasis.

RESULTS

The total sperm retrieval rate was 40%. Ten men with normal spermatogenesis were excluded. The remaining 110 men with non-obstructive azoospermia were analyzed and testicular microlithiasis was detected in 16 of them (14.5%). The sperm retrieval rate in that subgroup was only 6.2% (1/16) as opposed to 39.4% (37/94) in men with non-obstructive azoospermia and no evidence of microlithiasis (P = 0.009). The mean right and left testicular diameters were significantly lower in the microlithiasis group (P = 0.04). On multivariate logistic regression analysis, the presence of mictolithiasis (odds ratio 7.4, 95% confidence interval 2.3, 12.2; P = 0.01) was the only independent predictor of unsuccessful sperm retrieval. The 15 patients with microlithiasis and without successful sperm extraction were diagnosed by histopathology as having Sertoli cells only. The 16th patient with successful sperm retrieval had a histopathology of mixed atrophy and was diagnosed with Klinefelter syndrome.

CONCLUSION

The presence of testicular microlithiasis is associated with low sperm retrieval rates among our cohort of men with non-obstructive azoospermia undergoing scrotal ultrasonography prior to microsurgical testicular sperm extraction. Larger, prospective studies should be conducted to confirm these findings.

Incidental Findings and How to Manage Them: Testis- A WFUMB Position Paper

Testicular incidentalomas are non-palpable, asymptomatic lesions, most frequently detected on ultrasound examinations. Each incidentaloma should undergo a standardized diagnostic workup to exclude malignancy and recognize other potentially significant non-malignant conditions that may first present with an incidental finding on scrotal ultrasound. This position statement of the World Federation of Ultrasound in Medicine and Biology (WFUMB) summarizes the available evidence on management of testicular incidentalomas and describes efficient management strategies with particular reference to the role of ultrasound techniques.

Historical trends for the standards in scrotal ultrasonography: What was, what is and what will be normal

BACKGROUND

Ultrasonography is the gold standard imaging method for scrotal investigation. Colour Doppler ultrasonography, contrast-enhanced ultrasonography and sonoelastography allow sonographers to assess size, echotexture, vascular features and stiffness of the scrotal organs and abnormalities. Scrotal ultrasonography has been used to investigate male reproductive health, scrotal pain, masses and trauma. However, ultrasonography thresholds/classifications used to distinguish normal and pathologic features of the scrotal organs have changed over time, and have not yet been fully standardized.

OBJECTIVES

To evaluate historical trends for the standards in scrotal ultrasonography: what was, what is and what will be normal.

METHODS

An extensive Medline search was performed identifying the most relevant studies in the English language from inception to date.

RESULTS

We provide here (i) a brief overview of the history of ultrasonography, (ii) current indications for scrotal ultrasonography and (iii) previous and current normal values, cut-offs and classifications of the main colour-Doppler ultrasonography parameters/characteristics of the scrotal organs, as derived from recent guidelines and evidence-based studies. In addition, we report recommendations and the clinical utility of contrast-enhanced ultrasonography and sonoelastography. Finally, we discuss critical issues needing further evidence and future directions to fill in the current gaps.

DISCUSSION

Several studies on scrotal ultrasonography are available. However, guidelines/recommendations dealing with specific ultrasonography applications have been published only in recent years. More recently, the European Academy of Andrology published evidence-based scrotal colour-Doppler ultrasonography reference ranges/normative parameters derived from a cohort of healthy, fertile men. In addition, a standardization of the methodology to evaluate qualitative and quantitative colour-Doppler ultrasonography parameters was reported. Other international societies reported indications, methodological standards, clinical utility and limitations of contrast-enhanced ultrasonography and sonoelastography.

CONCLUSIONS

To date, colour-Doppler ultrasonography normative values for the scrotal organs are available. However, a wide international consensus on assessment and classification of several ultrasonography parameters is still lacking. An alignment of the world societies on these issues is advocated.

Prevalence of testicular microlithiasis in healthy newlywed men trying for first-time pregnancy

OBJECTIVES

To investigate the prevalence of testicular microlithiasis and the relationship between testicular microlithiasis, semen parameters and endocrinological profiles in healthy newlywed men trying for first-time pregnancy.

METHODS

Men visiting Juntendo University Urayasu Hospital, Urayasu, Chiba, Japan, or D Clinic Tokyo, Chiyoda-ku, Tokyo, Japan, for a first-time examination of fertility underwent scrotal examination, semen analysis and blood tests. Testicular volume measured by orchidometer, semen parameters measured by the Makler counting chamber and endocrinological profiles were compared between men with testicular microlithiasis and without testicular microlithiasis. The correlation between sperm concentration and the number of calcifications, and sperm motility and the number of calcifications, were investigated.

RESULTS

Of 739 men, 60 (8.1%) were diagnosed as having testicular microlithiasis. Among them, testicular volume, semen volume and motility were lower than those in the men without testicular microlithiasis. Luteinizing hormone and follicle-stimulating hormone levels were higher in those with than those without testicular microlithiasis. The sperm concentration correlated negatively with the number of calcifications. There was no significant correlation between sperm motility and the number of calcifications.

CONCLUSION

Herein, we report the prevalence of testicular microlithiasis in healthy newlywed men. Furthermore, our findings suggest that semen parameters in men with severe testicular microlithiasis tend to be worse.

Testicular ultrasound score: A new proposal for a scoring system to predict testicular function

Background

Testicular ultrasound (US) is routinely employed in the evaluation of reproductive and sexual function. However, its use for characteristics other than testicular volume is hampered by a lack of information on the prognostic value of its findings, which to date have only been incorporated in a score proposed by Lenz et al in 1993.

Objectives

We sought to explore whether testicular US examination can predict the quality of spermatogenesis and provide information on testicular endocrine function.

Materials and methods

We retrospectively reviewed 6210 testicular US examinations, finally selecting examinations from 2230 unique men. The following variables were considered: bitesticular volume and testicular asymmetry, parenchymal echotexture, echogenicity and presence of microlithiasis, solid lesions and varicocoele. Concurrent fasting hormonal data were available for 1160 men, while 979 had a semen sample available from the same day as the US examination.

Results

We derived a new US score, termed TU score, that can predict both impaired spermatogenesis (AUC 0.73, sensitivity 72%, specificity 61%, P < .001) and hypogonadism (AUC 0.71, sensitivity 71%, specificity 53%, P < .001) more accurately than the Lenz's score. In a multivariate analysis, a reduced sperm composite index (defined as total spermatozoa × total motility × normal forms) was independently predicted by bitesticular volume and by inhomogeneous echotexture, while hypogonadism was independently predicted also by reduced echogenicity and presence of microlithiasis.

Discussion and conclusions

We describe the testicular US characteristics that are independently associated with impaired spermatogenesis and hypogonadism and propose the TU score as a simple screening method for use in subjects referred for testicular US.

Testicular microlithiasis: what urologists should know. A review of the current literature

Introduction

Testicular microlithiasis is a finding incidental to the ultrasound examination of the scrotum. This article presents some new data regarding the etiopathology of testicular microliths. As there is a growing body of literature available, which associates testicular microlithiasis with a testicular germ cell tumor or male infertility, our review focuses on these relations (based on a new meta-analysis and retrospective follow-up programs). The purpose of this review is to summarize the knowledge about testicular microlithiasis and discuss the latest recommendations.

Material and methods

A comprehensive literature review was performed using Science Direct and Scopus with MeSH terms and keywords 'testicular microlithiasis', testicular tumor', male infertility'.

Results

The clinical consequences of testicular microlithiasis depend on the co-occurrence of specific risk factors. The presence of testicular microlithiasis alone in the absence of risk factors is not an indication for further investigation.

Conclusions

A link between testicular microlithiasis and testicular cancer as well as male infertility has been analyzed. Follow-up is only recommended where risk factors of testicular cancer other than testicular microlithiasis are present.

Bilateral methachronous testicular germ cell tumor and testicular microlithiasis in a child: Genetic analysis and insights. A case report

OBJECTIVES

To report our experience with a case of a child with bilateral testicular micro-lithiasis (TML) who developed bilateral metachronous testicular germ cell tumor (TGCT) and determine the most appropriate follow-up and care management in children with testicular micro calcifications in regards to the theoretical risk of testicular cancer.

CASE REPORT

A 12 year-old boy was diagnosed with TGCT and TML. Ten years after complete remission, he presented with a recurrence on the contralateral testis. Genetic screening was performed on both resected and the patient's karyotype was analyzed.

RESULTS

Blood karyotype was normal. Aberrations were found in the tumor karyotype. CGH array showed alterations in chromosome arm 12p.

DISCUSSION

TML is frequently associated with testicular malignancy in adults: in 16.9% of cases the normal contralateral testicle develops TML in TGCT. Recent works of literature find no relationship between TML and cancer in general, but in patients with additional risks, the relationship becomes stronger. Some authors suggest that environmental components and genetics are determinant factors. This is highly suspected in our reported case. It would seem that TML is not a precancerous lesion per se, but rather a marker of an at-risk situation. Long term evolution is uncertain and regular self-palpation that starts before puberty is the only way to ensure proper screening and monitoring.

CONCLUSION

TML have been suspected to be a sign of testicular dysgenesis syndrome, which yields a risk of developing TGCT in case of noxious associations. In patients with a history of TGCT contralateral TML is alarming and aggressive surgical management should be discussed. Therapeutic education of these patients on self-palpation is the best way to ensure proper follow-up.

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.

Long-term clinical course in three patients with MAMLD1 mutations

Although MAMLD1 on chromosome Xq28 is known as a causative gene for 46,XY disorders of sex development, clinical information is virtually limited in patients of infancy to early childhood. Here, we report long-term genital and hormonal findings in three previously described Japanese patients with MAMLD1 mutations, i.e., patients 1 and 2 with p.E197X and patient 3 with p.R726X. As previously reported, patients 1-3 exhibited penoscrotal hypospadias with chordee, microphallus, bifid/hypoplastic scrotum, and/or bilateral cryptorchidism/retractile testes, in the presence of sufficiently high serum basal or hCG-stimulated testosterone values in the mini-pubertal period to early childhood. Subsequently, patient 1 had low serum hCG-stimulated testosterone value (126 ng/dL) at 13 11/12 years of age, and manifested microphallus (4.5 cm), relatively small testes (left 8 mL and right 10 mL), Tanner stage 3 genitalia and pubic hair development at 18 3/12 years of age. Similarly, patients 2 and 3 showed mild hypergonadotropic hypogonadism at 7 0/12 and 9 9/12 years of age, respectively, with serum GnRH-stimulated LH values of 5.5 and 7.2 mIU/mL and FSH values of 10.3 and 19.8 mIU/mL and hCG-stimulated testosterone values of 70 and 80 ng/dL, respectively. Testis ultrasound studies delineated microlithiasis in patients 1 and 3. These results imply for the first time deterioration of testicular function with age in patients with pathologic MAMLD1 mutations.

Testicular microlithiasis and associated testicular malignancies in childhood: a systematic review

The aim was to perform a systematic review to evaluate the published data on testicular microlithiasis (TM) in the pediatric population and to explore the association of TM with testicular malignancy as well as to propose guidelines to aid decision making on pediatric patients with TM. Outcome data for pediatric TM should be interpretated with caution due to the poor quality evidence available. Whilst the link with testicular neoplasms is undisputed (<5%) active screening programmes require robust evidence to support their wider deployment. Testicular self-examination though would appear advisable for all patients with testicular microlithiasis.

Familial testicular germ cell tumors (FTGCT) - overview of a multidisciplinary etiologic study

This Review summarizes the cumulative results of the National Cancer Institute Clinical Genetics Branch Multidisciplinary Etiologic Study of Familial Testicular Germ Cell Tumors (FTGCT). Initiated 12 years ago, this protocol enrolled 724 subjects from 147 unrelated families with either ≥2 affected men (n = 90) with TGCT or a proband with bilateral TGCT and a negative family history for this cancer (n = 57). Data were collected directly from 162 subjects evaluated at the NIH Clinical Center, and 562 subjects provided information from their home communities (Field Cohort). The primary study aims included (i) ascertaining, enrolling eligible FTGCT kindred, (ii) characterizing the clinical phenotype of multiple-case families, (iii) identifying the underlying genetic mechanism for TGCT susceptibility in families, (iv) evaluating counseling, psychosocial, and behavioral issues resulting from membership in an FTGCT family, and (v) creating an annotated biospecimen repository to permit subsequent translational research studies. Noteworthy findings include (i) documenting the epidemiologic similarities between familial and sporadic TGCT, (ii) demonstrating significantly younger age-at-diagnosis for familial vs. sporadic TGCT, (iii) absence of a dysmorphic phenotype in affected family members, (iv) shifting the focus of gene discovery from a search for rare, highly penetrant susceptibility variants to the hypothesis that multiple, more common, lower penetrance genes underlie TGCT genetic risk, (v) implicating testicular microlithiasis in FTGCT risk, and (vi) observing that aberrant methylation may contribute to FTGCT risk. A clinically based, biospecimen-intensive, multidisciplinary research strategy has provided novel, valuable insights into the etiology of FTGCT, and created a research resource which will support FTGCT clinical and laboratory studies for years to come.

Basic diagnostics in andrology

Basic andrological diagnosis consists of taking the patient's medical history and the couple's history as well as performing a physical examination including genital ultrasound, spermiogram, and hormonal analysis. If needed, a testicular biopsy and genetic testing may also be performed. Recent studies have shown the effect of lifestyle factors on male fertility. Thus, the patient history and clinical/andrological examinations have been broadened to include information on metabolic disorders like obesity and diabetes mellitus. The biggest changes occurred with the publication of the fifth edition of the WHO laboratory manual in 2010 and the introduction of a section on semen analysis in the German Medical Association guidelines (RiliBÄK). The reference values for almost all spermiogram parameters were adapted in an evidence-based approach using worldwide prospective population studies. For central parameters such as sperm motility and morphology, the assessment criteria were changed. New independent markers such as sperm DNA fragmentation rate are now routinely used in clinical diagnosis. For German andrological laboratories, there are now mandatory quality assurance measures for semen analysis (in the German "Rili-BÄK" guidelines). These include duplicate testing of all standard semen parameters and inter-laboratory comparison at regular intervals.

Testicular microlithiasis an ultrasound dilemma: survey of opinions regarding significance and management amongst UK ultrasound practitioners

OBJECTIVE

To establish whether there is a consensus regarding the significance of testicular microlithiasis and a strategy for managing patients with this condition, amongst ultrasound practitioners in the UK.

METHODS

An electronic questionnaire was distributed to 1482 members of the British Medical Ultrasound Society (BMUS), requesting information from ultrasound practitioners involved in scrotal ultrasound about their interpretation of the risk associated with testicular microlithiasis and their departmental or personal recommendations for managing patients with this condition.

RESULTS

Responses were obtained from 221 BMUS members. Analysis demonstrated a wide variation in the significance attributed to the discovery of testicular microlithiasis and the risk of subsequent development of testicular germ cell tumours. There was also great variation in strategies for management of patients with testicular microlithiasis, including the need for surveillance ultrasound, amongst ultrasound practitioners regardless of their job description.

CONCLUSION

Lack of consensus shown by this study highlights significant differences across the UK in managing patients with testicular microlithiasis and validates the importance of guidance currently being formulated by the European Society of Urogenital Radiology.

ADVANCES IN KNOWLEDGE

We believe that this is the first survey to be conducted amongst imaging specialists in the UK regarding testicular microlithiasis and demonstrates that there is currently no uniform practice in managing patients with this condition.

Testis tumor associated to microlithiasis

OBJECTIVE:

To discuss the relationship between testicular microlithiasis and testis tumors in children and to consider the chances of testis preserving surgery in specific cases.

CASE DESCRIPTION:

Pre-adolescent presenting testicular microlithiasis and a larger left testis, corresponding to a cystic testicular tumor. The tumor was excised, with ipsilateral testis preservation. Histology diagnosed a testis dermoid tumor.

COMMENTS:

The relationship between testis tumors and testicular microlithiasis is ill defined in children. Pediatric urologists need to develop specific follow-up protocols for pre-pubertal children.

Pulmonary alveolar microlithiasis with concurrent pleural mesothelioma in a dog

Pulmonary alveolar microlithiasis (PAM) is a rare pulmonary disorder characterized by the accumulation of calcium phosphate microliths within the alveoli, with only a few cases described in animals. A 10-year-old female Bulldog was euthanized due to history of dyspnea and recurrent pleural and pericardial effusions. At necropsy, numerous multifocal to coalescent protruding nodules of 1-5 mm in diameter were scattered throughout the thoracic serosal surfaces. Moreover, lungs showed a diffuse pale gray color and had a generalized fine grainy consistency. Histological investigations revealed abundant intra-alveolar laminated microliths that stained positive with periodic acid-Schiff and von Kossa stains. The pulmonary interstitium showed multifocal, mild to moderate thickening, due to collagen deposition and mild hyperplasia of type 2 pneumocytes. The pulmonary lesion was not associated with any inflammatory response, and mineral deposition was not observed in any other organ or tissue. In addition, pulmonary, pericardial, and pleural surfaces were extensively infiltrated by an epithelioid mesothelioma. Immunohistochemical staining revealed neoplastic cells that strongly coexpressed vimentin and cytokeratin, supporting the diagnosis of mesothelioma. An overview of PAM, including pathogenesis and histological characteristics, are discussed in relation to the concurrent pleural mesothelioma. The potential cause and effect relationship between the 2 conditions could neither be established nor ruled out.