Contrast-enhanced ultrasound and real-time elastography for the diagnosis of benign Leydig cell tumors of the testis - a single center report on 13 cases

Contrast-enhanced ultrasound (CEUS) for the characterization of intra-scrotal lesions

Contrast-enhanced ultrasound (CEUS) has emerged as a promising imaging modality for the characterization of hepatic and renal lesions. However, there is a paucity of data describing the use of CEUS for the evaluation of intra-scrotal pathology. In the following review, we describe the clinical utility of CEUS for the characterization and differentiation of common and uncommon intra-scrotal conditions, including testicular torsion, infection, trauma, and benign and malignant intratesticular and extratesticular neoplasms. In addition, we outline key principles of CEUS and provide case examples from our institution.

Diagnosis and management of indeterminate testicular lesions

The sophistication and accessibility of modern-day imaging result in frequent detection of small or equivocal lesions of the testes. Traditionally, diagnosis of a testicular lesion with any possibility of malignancy would usually prompt radical orchidectomy. However, awareness is growing that a substantial proportion of these lesions might be benign and that universal application of radical orchidectomy risks frequent overtreatment. Given the potentially profound effects of radical orchidectomy on fertility, endocrine function and psychosexual well-being, particularly in scenarios of an abnormal contralateral testis or bilateral lesions, organ-preserving strategies for equivocal lesions should be considered. Image-based active surveillance can be applied for indeterminate lesions measuring ≤15 mm with a low conversion rate to surgical treatment. However, these outcomes are early and from relatively small, selected cohorts, and concerns prevail regarding the metastatic potential of even small undiagnosed germ cell tumours. No consensus exists on optimal surveillance (short interval (<3 months) ultrasonography is generally adopted); histological sampling is a widespread alternative, involving inguinal delivery of the testis and excisional biopsy of the lesion, with preoperative marking or intraoperative ultrasonographic localization when necessary. Frozen section analysis in this context demonstrates excellent diagnostic accuracy. Histological results support that approximately two-thirds of marker-negative indeterminate solitary testicular lesions measuring ≤25 mm overall are benign. In summary, modern imaging detects many small indeterminate testicular lesions, of which the majority are benign. Awareness is growing of surveillance and organ-sparing diagnostic and treatment strategies with the aim of minimizing rates of overtreatment with radical orchidectomy.

Multiparametric Ultrasound for Diagnosing Testicular Lesions: Everything You Need to Know in Daily Clinical Practice

BACKGROUND

Ultrasonography (US) represents the gold standard imaging method for the assessment of testicular lesions (TL). The gray-scale (GSUS) and color-Doppler (CDUS) ultrasound examination allow sonographers to investigate the size, margins, echotexture, and vascular features of TLs with the aim to differentiate benign from malignant lesions. Recently, the use of contrast-enhanced US (CEUS) and sonoelastography (SE) has led to further improvements in the differential diagnosis of TL. Although GSUS and CDUS are often sufficient to suggest the benign or malignant nature of the TL, CEUS can be decisive in the differential diagnosis of unclear findings, while SE can help to strengthen the diagnosis. The contemporary combination of GSUS, CDUS, CEUS, and SE has led to a new diagnostic paradigm named multiparametric US (mp-US), which is able to provide a more detailed characterization of TLs than single techniques alone. This narrative and pictorial review aimed to describe the mp-US appearance of several TLs.

METHODS

An extensive Medline search was performed to identify studies in the English language focusing on the mp-US evaluation of TLs.

RESULTS

A practical mp-US "identity card" and iconographic characterization of several benign and malignant TLs is provided herein.

CONCLUSIONS

The mp-US characterization of TL reported herein can be useful in daily clinical practice.

Sonoelastography for Testicular Tumor Identification: A Systematic Review and Meta-Analysis of Diagnostic Test Accuracy

The objective of this review was to summarize the applications of sonoelastography in testicular tumor identification and inquire about their test performances. Two authors independently searched English journal articles and full conference papers from CINAHL, Embase, IEEE Xplore®, PubMed, Scopus, and Web of Science from inception and organized them into a PIRO (patient, index test, reference test, outcome) framework. Eleven studies (n = 11) were eligible for data synthesis, nine of which (n = 9) utilized strain elastography and two (n = 2) employed shear-wave elastography. Meta-analyses were performed on the distinction between neoplasm (tumor) and non-neoplasm (non-tumor) from four study arms and between malignancy and benignity from seven study arms. The pooled sensitivity of classifying malignancy and benignity was 86.0% (95%CI, 79.7% to 90.6%). There was substantial heterogeneity in the classification of neoplasm and non-neoplasm and in the specificity of classifying malignancy and benignity, which could not be addressed by the subgroup analysis of sonoelastography techniques. Heterogeneity might be associated with the high risk of bias and applicability concern, including a wide spectrum of testicular pathologies and verification bias in the reference tests. Key technical obstacles in the index test were manual compression in strain elastography, qualitative observation of non-standardized color codes, and locating the Regions of Interest (ROI), in addition to decisions in feature extractions. Future research may focus on multiparametric sonoelastography using deep learning models and ensemble learning. A decision model on the benefits-risks of surgical exploration (reference test) could also be developed to direct the test-and-treat strategy for testicular tumors.

Leydig Cell Tumors of the Testis: An Update of the Imaging Characteristics of a Not So Rare Lesion

Simple Summary

Stromal tumors of the testis are rare. However, among this group, Leydig cell tumors (LCT) are the most frequent, and recent studies suggest that LCTs account for up to 22% of small testicular nodules. It is now accepted that small LCTs can benefit from testis-sparing surgery or in some selected cases radiological surveillance. Since percutaneous testicular biopsy is still not recommended, the diagnosis of LCT rests on multimodal imaging techniques. Therefore, it is essential for the radiologist and the urologist to know the main imaging features of LCTs in ultrasound and MRI.

Abstract

Pre-operative testicular tumor characterization is a challenge for radiologists and urologists. New data concerning imaging approaches or immunochemistry markers improve the management of patients presenting with a testicular tumor, sometimes avoiding radical orchiectomy. In the past 20 years, imaging modalities, especially ultrasound (US) and magnetic resonance imaging (MRI), improved, allowing for great progress in lesion characterization. Leydig cell tumors (LCT) are rare testicular tumors developing from the stromal tissue, with relatively scarce literature, as most of the studies focus on the much more frequent germ cell tumors. However, with the increase in testicular sonography numbers, the incidence of LCT appears much higher than expected, with some studies reporting up to 22% of small testicular nodules. Multimodal ultrasound using Doppler, Elastography, or injection of contrast media can provide crucial arguments to differentiate LCT from germ cell tumors. Multiparametric MRI is a second intention exam, but it allows for extraction of quantifiable data to assess the diagnosis of LCT. The aims of this article are to review the latest data regarding LCT imaging features, using multimodal ultrasound and multiparametric MRI, and to focus on the peculiar aspect of the testis of patients with Klinefelter’s syndrome. The possibility of an LCT should be raised in front of a small hypoechoic tumor with a marked corbelling hypervascularization in an otherwise normal testicular pulp. Ultrasonographic modules, such as ultrasensitive Doppler, contrast-enhanced ultrasonography, or elastography, can be used to reinforce the suspicion of LCT. MRI provides objective data regarding vascularization and enhancement kinetics.

Leydig Cell Tumor-Induced Gonadotropin-Independent Precocious Puberty Progressing to Gonadotropin-Dependent Precocious Puberty Post Orchiectomy: Out of the Frying Pan Into the Fire

Many pathologies can cause gonadotropin-independent precocious puberty (GIPP) in prepubertal boys. Leydig cell tumor is one rare cause of this presentation. Here we present a six-year-old boy with features of isosexual precocious puberty, high testosterone levels, low gonadotropin levels, and bone age advancement. Testicular USG revealed a left-sided testicular tumor. The left testis was removed surgically, and the Leydig cell tumor was confirmed on histopathology. Post orchiectomy, the boy had elevated testosterone levels with raised luteinizing hormone (LH) levels. A diagnosis of gonadotropin-dependent precocious puberty (GDPP) was made. He has been initiated on monthly gonadotropin-releasing hormone (GnRH) agonist therapy.

Ultrasonography of the scrotum: Revisiting a classic technique

Conventional US is the primary imaging modality for the evaluation of the scrotum, due to its high resolution, availability, cost-effectiveness and absence of ionizing radiation. Grayscale and color Doppler US provide a comprehensive assessment of scrotal diseases. The technique represents the mainstay for imaging of acute scrotum. US is highly accurate in the detection, localization and characterization of scrotal masses. Multiparametric US, including conventional US, contrast-enhanced US and tissue elastography has improved the diagnostic performance of the technique in the assessment of testicular diseases. MRI represents a valuable supplemental imaging tool for the investigation of scrotal pathology, mainly recommended in cases of indeterminate US findings. Recommendations recently issued by the European Society of Urogenital Radiology Scrotal and Penile Imaging Working Group (ESUR-SPIWG) refer to the use of scrotal sonography for the evaluation of pathologic entities, including testicular microlithiasis, small, non-palpable incidentally detected testicular masses, varicocele and scrotal trauma. In this review, the technical specifications for scrotal US and the normal sonographic findings are presented. Grayscale and color Doppler US findings of common acute scrotal diseases and scrotal masses are discussed. The complimentary role of multiparametric US and scrotal MRI is addressed. ESUR-SPIWG's guidelines are also reviewed.

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.

Use of contrast enhanced ultrasound in testicular diseases: A comprehensive review

Background

Contrast‐enhanced ultrasound (CEUS) is a sonographic technique that increases the diagnostic accuracy of ultrasound and color Doppler ultrasound (CDUS) when studying testicular abnormalities. However, its role in clinical practice is still debatable because there are no accepted standards regarding how and when this technique should be used for patients with testicular disease.

Objectives

To perform a nonsystematic review of the current literature to highlight the strength and flaws of performing CEUS and to provide a critical overview of current research evidence on this topic.

Materials and methods

A thorough search of published peer‐reviewed studies in PubMed was performed using proper keywords.

Results

Strong enhancement of neoplastic lesions (both benign and malignant) during CEUS aids in differential diagnosis with non‐neoplastic lesions, which usually appears either nonenhanced or enhanced in a manner similar to that of the surrounding parenchyma. CEUS enhancement has a high predictive value in the identification of neoplastic lesions, whereas a similar or complete absence of enhancement may be interpreted as strong evidence of benignity, although there are exceptions. Literature on quantitative analysis is still scarce, though promising, particularly in distinguishing benign from malignant neoplasms. Furthermore, CEUS may be useful in many emergency situations, such as acute scrotum, blunt scrotal trauma, and focal infarction of the testis. Finally, CEUS can help increase the probability of sperm recovery in azoospermic males.

Discussion and conclusion

CEUS is a safe, easy‐to‐perform, and cost‐effective diagnostic tool that can provide a more accurate diagnosis in testicular lesions and acute scrotal disease. However, further studies with larger cohorts are required to refine the differential diagnosis between benign and malignant neoplasms. Finally, these preliminary results can instigate the development of innovative research on pre‐testicular sperm extraction to increase the chances of sperm recovery.

THE ROLE OF ULTRASOUND ELASTOGRAPHY IN THE DIAGNOSIS OF PATHOLOGIC CONDITIONS OF TESTICLES AND SCROTUM

Several years ago, elastography emerged as a potentially very useful ultrasound technique that is currently used in diagnostic workup of the breast, liver and some other organ systems, whereas for other ones it is still mainly in the phase of research. The aim of the study was to compare elasticity index (EI) of testicles using strain elastography in healthy subjects and those with pathologic changes of testicles/scrotum. A total of 117 patients were included in the study. Measurements were performed on a Logiq E9 ultrasound system using strain elastography. In healthy subjects, the mean EI value was 1.34±0.35 for right testis and 1.49±0.47 for left testis. Increased mean EI values were found in the following six conditions: patients with varicocele, infertile patients, solitary testis after orchidectomy of the other testicle because of tumor, patients with testicular tumors, patients after orchidopexy of undescended testicle, and patients with congenitally smaller testicle. There is a paucity of literature data on the use of elastography in testes, as well as on normal elastography values in testicular tissue. Strain elastography was demonstrated to be a valuable method to acquire additional information in patients with pathologic changes in testicles/scrotum. These data provide reference values for further research in a larger sample of subjects.

Vascularity of Intra-testicular Lesions: Inter-observer Variation in the Assessment of Non-neoplastic Versus Neoplastic Abnormalities After Vascular Enhancement With Contrast-Enhanced Ultrasound

The aim of this study is to assess the additional benefit of contrast-enhanced ultrasound (CEUS) over conventional ultrasonography (US) in identifying intra-testicular abnormalities among observers of different experiences. In this study, 91 focal testicular lesions (46 neoplastic, 45 non-neoplastic) imaged with gray-scale US/Doppler US and CEUS were classified using a 5-point scale. Three experienced and four inexperienced observers rated each lesion using gray-scale/color Doppler US alone and then with the addition of CEUS. Improved diagnostic specificity and accuracy with the addition of CEUS was observed for both experienced (specificity: 71.1% vs. 59.3%, p = 0.005; accuracy: 83.5% vs. 76.9%, p = 0.003) and inexperienced observers (specificity: 75.6% vs. 51.7%, p = 0.005; accuracy: 80.2% vs. 72.0%, p < 0.001). Significant inter-observer variability between the experienced and inexperienced observers when assessing conventional US alone was eliminated with the addition of CEUS. CEUS improves diagnostic accuracy of focal intra-testicular lesions for both experienced and inexperienced observers and reduces inter-observer variability in inexperienced operators.

The role of multiparametric ultrasound in the diagnosis of paediatric scrotal pathology

Multiparametric ultrasound (MPUS), combining conventional techniques (greyscale and colour Doppler ultrasound), ultrasound strain elastography, and contrast-enhanced ultrasound (CEUS), has been successfully used in the assessment of adult scrotal pathology. Contrast-enhanced ultrasound can confidently establish testicular tissue vascularity even in the small-volume paediatric testis. Elastography provides further assessment of tissue stiffness, potentially adding useful diagnostic information. In children, ultrasonography is particularly advantageous, being safe, radiation-free and negating the need for sedation or general anaesthesia during the imaging evaluation. In this review article, we aim to familiarise readers with the MPUS scanning protocol used for paediatric scrotal examination and provide an overview of scrotal MPUS features, with particular focus to clinical indications where MPUS may be advantageous over conventional ultrasonography.

Testicular tumours in children: an approach to diagnosis and management with pathologic correlation

Testicular tumours are rare in children. Painless scrotal mass is the most frequent clinical presentation. Tumoural markers (alpha-fetoprotein, beta-human gonadotropin chorionic) and hormone levels (testosterone) contribute to the diagnosis and management of a testicular mass in boys. Ultrasonography is the best imaging modality to study testicular tumours. A benign tumour is suggested when ultrasonography shows a mainly cystic component, well-defined borders, echogenic rim or normal to increased echogenicity lesion when compared to the healthy testicular parenchyma. Malignant tumour is suspected when ultrasonography shows inhomogeneous, hypoechoic, not well-circumscribed or diffuse infiltration lesion. However, these ultrasonographic findings may overlap. Colour Doppler, power Doppler, elastography and contrast-enhanced ultrasonography are useful complementary methods to characterise the focal testicular lesions. Chest computerised tomography and abdominopelvic magnetic resonance are necessary to establish the extension in case of malignant proved tumours.Benign tumours are more frequent in prepuberal boys and malignant tumours in pubertal boys. Mature teratoma prepubertal-type is the most common histologic type. Testicular sparing surgery is the choice in benign tumours. Radical inguinal orchiectomy is indicated in malignant tumours. Prognostic is excellent.The purpose of our study is to show an approach to the diagnosis and management of the most frequent testicular tumours in children according to clinical manifestations, imaging findings and tumour markers levels based on histologically confirmed tumours in our hospital.

Multiparametric ultrasonographic analysis of testicular tumors: a single-center experience in a collective of 49 patients

Purpose: The aim of the present retrospective single-center study is to evaluate the diagnostic performance of multiparametric ultrasonography for characterizing testicular tumors.Method: Forty-nine patients with testicular tumors, 36 of malignant vs 13 of benign entity, were included in this retrospective single-center study on whom multiparametric sonography, encompassing native B-mode, Color Doppler, contrast-enhanced ultrasound (CEUS) and elastography, was performed between 2011-2018. In 48 of 49 patients, findings from multiparametric analysis were correlated with histopathological results. The applied contrast agent for CEUS was a second-generation blood pool agent. Ultrasonography examinations were performed and interpreted by a single experienced radiologist with more than 15 years of experience (EFSUMB Level 3).Results: Multiparametric ultrasonography was successfully performed in all included patients without any adverse effects. Concomitant testicular microlithiasis, rapid arterial wash-in, elevated values for perfusion quantification - Peak Enhancement (PE), Wash-in Area Under the Curve (WiAUC) and Wash-in Perfusion Index (WiPI) - and higher shear wave velocities were significantly associated with malignancy.Conclusions: Multiparametric ultrasonography depicts a non-ionizing, directly accessible and cost-effective imaging modality that allows for the extensive characterization of testicular tumors, thereby helping to discriminate between malignant and benign entity of testicular tumors.

Multiparametric Ultrasound (mpUS) of a Rare Testicular Capillary Hemangioma

Capillary hemangioma is a rare entity among testicular tumors. We demonstrate the case of an 18-year-old patient with palpatoric and sonographic conspicuous left testicle and negative serum tumor markers (α-fetoprotein, β-human chorionic gonadotropin, and lactate dehydrogenase). Ultrasound (US) imaging represented an isoechogenic lesion with high vascularization in both power Doppler and microflow imaging with central feeding artery. Both strain elastography and shear wave elastography demonstrated a stiff lesion compared to surrounding testicular tissue. While contrast-enhanced ultrasound (CEUS) clearly depicted high vascular load, time intensity curve (TIC) analysis was able to show shorter median transit time, higher peak enhancement, and higher wash-in area under the curve compared to regular testicular tissue. Histopathological examination revealed a lobular constructed and rich vascularized proliferation without cellular atypia and feeder vessels with positive reaction to CD34, CD31, CD99, and Vimentin. Proliferative activity was quantified to 3–5% by Ki-67 index. Two days after surgery, the patient could leave the hospital in subjective wellbeing. While histology remains the gold standard to make a precise diagnosis of capillary hemangiomas due to small case numbers and variety of this benign tumor, the combination of multiparametric US and clinical information may be a promising future tool in preoperative assessment.

ESMO Consensus Conference on testicular germ cell cancer: diagnosis, treatment and follow-up

The European Society for Medical Oncology (ESMO) consensus conference on testicular cancer was held on 3-5 November 2016 in Paris, France. The conference included a multidisciplinary panel of 36 leading experts in the diagnosis and treatment of testicular cancer (34 panel members attended the conference; an additional two panel members [CB and K-PD] participated in all preparatory work and subsequent manuscript development). The aim of the conference was to develop detailed recommendations on topics relating to testicular cancer that are not covered in detail in the current ESMO Clinical Practice Guidelines (CPGs) and where the available level of evidence is insufficient. The main topics identified for discussion related to: (1) diagnostic work-up and patient assessment; (2) stage I disease; (3) stage II-III disease; (4) post-chemotherapy surgery, salvage chemotherapy, salvage and desperation surgery and special topics; and (5) survivorship and follow-up schemes. The experts addressed questions relating to one of the five topics within five working groups. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel. A consensus vote was obtained following whole-panel discussions, and the consensus recommendations were then further developed in post-meeting discussions in written form. This manuscript presents the results of the expert panel discussions, including the consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.

[Contrast-enhanced ultrasonography of testicular tumours]

Scrotal ultrasound with high-resolution transducers and additional display of vascularisation in colour-coded ultrasonography is the method of choice for the detection and characterisation of testicular tumors. Within the last decade, testicular ultrasonography has been further refined and improved by the possibilities of contrast-enhanced ultrasound (CEUS).CEUS may be especially helpful in the assessment of vascularisation disorders (e.g., incomplete torsion, segmental perfusion disorders, abscesses) or testicular foci remaining equivocal even after colour-coded ultrasonography.The basic idea in the application of CEUS in scrotal sonography is the possibility to differentiate between avascular, hypo- and hypervascular findings, with a lack of perfusion generally considered as a sign of benignity. Vice versa, detection of vascularisation speaks for neoplasia but not necessarily for malignity (e.g., Leydig cell tumors). CEUS is especially valuable in the correct classification of small (<1.5 cm) testicular foci.This review summarizes the present knowledge on indications, implications and limitations of the application of CEUS in testicular tumors.

[Testicular tumors: A diagnostic challenge of imaging]

OBJECTIVES

Reviewing the characterization and the follow-up imaging of testicular tumors.

MATERIAL AND METHODS

Literature review (PubMed, Medline) of urological and radiological studies dealing with testicular tumors using keywords: Testicular tumors; Color Doppler ultrasound; US elastography; Magnetic resonance imaging; Contrast enhanced sonography.

RESULTS

Ultrasound remains the basic exam for the tumor characterization. Among the other techniques, MRI, elastography, contrast enhanced ultrasound, although still in evaluation, will be increasingly used in the future. The frequency of benign Leydig cell tumors justifies a testicular preservation approach, through improvement of characterization, monitoring or tumorectomy. The follow-up of testicular lesions must be indicated on precise indications: follow-up of the contralateral testicle in the case of germi cell tumor, follow-up by of a supposed benign lesion, such as a small Leydig cell tumor in an infertile patient, follow-up when ultra-sound findings are not sufficiently worrying to require immediate diagnosis but which include pejorative criteria. The tumor markers and the extension screening remain systematic.

CONCLUSION

The era of total orchiectomy for any uncertain testicular lesion is over. We try the challenge of characterization, and define management's algorithms based on clinical biological data and suspected nature of the tumor at imaging.

Characterization of Testicular Masses in Adults: Performance of Combined Quantitative Shear Wave Elastography and Conventional Ultrasound

We prospectively evaluated the performance of combined shear wave elastography (SWE) and conventional ultrasound (US) for the characterization of 89 testicular focal masses. Testes were evaluated with B-mode, color Doppler and SWE measurements, locating a region of interest on the normal and pathologic parenchyma. Thirty-seven malignant tumors (MTs), 12 burned out tumors (BOTs), 28 Leydig cell tumors (LCTs), 2 dermoid cysts and other benign lesions were included. MTs + BOTs exhibited more microliths and macrocalcifications compared with benign lesions (p < 10^-4). LCTs manifested mostly a dominant peripheral vascularization pattern compared with other lesions. MTs + BOTs were stiffer compared with benign lesions (p < 2 × 10^-4) but with a moderate area under the receiver operating characteristic curve (AUROC) of 80%. By focusing on LCTs versus MTs + BOTs, diagnostic performance led to an AUROC of 89% for the best stiffness parameter. For combined conventional US and SWE, the diagnostic performance to differentiate all benign lesions versus MTs + BOTs and LCTs versus MTs + BOTs increased to AUROCs of 93% and 98%, respectively.

Elastography of focal testicular lesions: current concepts and utility

As a relatively new sonographic technique, tissue elastography has emerged as a qualitative and potentially quantitative adjunctive tool to provide additional information on tissue stiffness, aiming to further improve diagnostic confidence in discriminating benign from malignant focal testicular lesions. The purpose of this review is to provide an overview of the elastography techniques used to assess focal testicular lesions and their typical appearance on tissue elastography.

Evaluation of Intratesticular Lesions With Strain Elastography Using Strain Ratio and Color Map Visual Grading: Differentiation of Neoplastic and Nonneoplastic Lesions

OBJECTIVE

To investigate the role of strain elastography using calculated strain ratio and visual elastography score in differentiating nonneoplastic, benign, and malignant neoplastic intratesticular lesions.

MATERIALS AND METHODS

The study was approved by the hospital review board as a retrospective review of 86 patients examined with gray scale, color Doppler ultrasonography and strain elastography (visual elastography score and strain ratio). Sensitivity, specificity, and positive and negative likelihood ratio of color Doppler and stain elastography were documented. Receiver operator characteristic curves assessed the diagnostic accuracy of strain elastography to discriminate nonneoplastic, benign, and malignant neoplasms. Histology or follow-up ultrasonography determined lesion character.

RESULTS

Thirty-one of 86 (36.0%) intratesticular malignant neoplasms, 17 of 86 (19.8%) benign neoplasms, and 38 of 86 (44.2%) nonneoplastic lesions were confirmed with histology (n = 52) or follow-up sonography (n = 34); 89.5% of intratesticular lesions were heterogeneous or hypoechoic on gray scale, with no difference between benign and malignant. Sensitivity, specificity, positive and negative likelihood ratio for nonneoplasm versus neoplasm were documented: color Doppler: 68.8%, 97.4%, 26.5, 0.32; visual elastography score: 81.3%, 57.9%, 1.93, 0.32; strain ratio: 68.8%, 81.6%, 3.73, 0.38. Neoplastic lesions showed a higher strain ratio than nonneoplastic lesions (P < .001), with strong correlation between median strain ratio and visual elastography score (Spearman's coefficient, 0.693; P < .001). Strain ratio is a significantly better assessment than visual elastography score for malignant lesions (P = .025). Logistic regression analysis revealed significant associations between size (P = .001), hypervascularity (P < .001), and malignancy.

CONCLUSION

Higher strain ratio and visual elastography score are associated with neoplastic lesions and offer an alternative to assess tissue characteristics but do not improve the diagnostic accuracy when compared with the color Doppler pattern.

[Non-palpable testicular tumors in adults: A management based on imaging? Issue from the French Urologic Association Genital Cancer committee's edit]

BACKGROUND

Help in management of non-palpable testicular tumors. French Urologic Association Genital cancer committee's Edit.

OBJECTIVES

To review their characterization at imaging findings of non-palpable testicular tumors.

DOCUMENTARY SOURCES

Literature review (PubMed, Medline) of urological and radiological studies dealing with testicular tumors using keywords: non-palpable/incidental testicular tumors; color Doppler ultrasound; US elastography; magnetic resonance imaging; contrast enhanced sonography; partial surgery.

RESULTS

Color Doppler is the basic exam. The size, the presence of microlithts/microlithiasis/macrocalcifications, the vascular architecture are major semiological findings to suggest the benign or the malignant nature of the lesion. Other techniques like multiparametric MRI, contrast-enhanced sonography, sonographic elastography are still in evaluation. The frequency of benign tumors such as Leydig cell tumors lead to preservation management, through improved characterization, monitoring or tumorectomy.

LIMITS

Non-randomized study - a very few prospective studies.

CONCLUSION

The era of total orchiectomy for any uncertain testicular lesion is over. We try the challenge of characterization, and define management's algorithms based on the suspected nature of the tumors.

Testicular ultrasensitive Doppler preliminary experience: a feasibility study

Background Ultrasensitive Doppler is a novel non-invasive ultrasound (US) Doppler technique that improves sensitivity and resolution for the detection of slow flow. Purpose To investigate the feasibility of ultrasensitive Doppler (USD) for testicular disease diagnosis, using both qualitative and quantitative results. Material and Methods This prospective study was conducted in 160 successive men referred for scrotal US including B-mode and conventional Color-Doppler. A new USD sequence and algorithm dedicated to academic research were implemented into the US system. The quality criterion for a successful examination was the detection of well delineated intratesticular vessels. Qualitative USD results were described in terms of tumor vascular architecture and flow intensity for different pathologies for 41 patients. The testicular vascularization (TV), defined as a vessel's surface ratio, was quantified using customized MATLAB® software and compared in azoospermic and normal patients. Results USD was acquired successfully in 153/160 patients (95.6%). The tumor vascular architecture differed depending on the nature of the tumors. Leydig cell tumors exhibited mostly circumferential vascularization, while germ cell tumors exhibited straight vessels through the tumors, or anarchic vascular maps. USD improved the diagnostic performance of testicular Doppler US in a case of incomplete spermatic cord torsion and acute epididymitis. The reproducibility of TV measurements established an interclass correlation of 0.801. Non-Klinefelter syndrome non-obstructive azoospermia patients exhibited a lower TV compared to normal patients, to Klinefelter syndrome, and to obstructive azoospermia patients ( P < 0.002, P < 0.005, and P < 0.05, respectively). Conclusion Testicular USD can become a promising technique for improving US diagnosis of tumors, acute scrotum, and for determining infertility status.

Comparison of Tissue Stiffness Using Shear Wave Elastography in Men with Normal Testicular Tissue, Testicular Microlithiasis and Testicular Cancer

Objectives

To compare elastography measurements in men with normal testicular tissue, testicular microlithiasis and testicular cancer.

Methods

A total of 248 consecutive patients were included. All men provided written informed consent. Testicular stiffness was assessed using shear wave elastography (SWE). Three SWE velocity measurements were assessed in each testicle. The patients were divided into three groups; men with normal testicular tissue (n=130), men with testicular microlithiasis (n=99) and men with testicular cancer (n=19).

Results

We found a higher mean velocity in the group of patients with testicular cancer (1.92 m/s (95% CI 1.82-2.03)) compared to both the group with normal tissue (0.76 m/s (95% CI: 0.75-0.78)) (p<0.001) and the group with testicular microlithiasis 0.79 m/s (95% CI: 0.77-0.81) (p<0.001).

Conclusion

The presence of testicular microlithiasis increased stiffness slightly, but within the range of variation in normal testicles. Increased stiffness may indicate testicular malignancy in testicular lesions. Ultrasound elastography could be a very useful tool when investigating scrotum.

Value of Multiparametric US in the Assessment of Intratesticular Lesions

Purpose To evaluate the diagnostic accuracy of multiparametric ultrasonography (US) consisting of gray-scale US, color Doppler US, strain elastography, and contrast agent-enhanced US in the assessment of intratesticular lesions. Materials and Methods Institutional review board approval was obtained for this retrospective study. From January 2012 to December 2015, 55 focal testicular lesions that were indeterminate on gray-scale US scans were further characterized with color Doppler US, strain elastography, and contrast-enhanced US. Strain elastography was performed to assess tissue elasticity, and hard lesions were defined as malignant. Color Doppler US and contrast-enhanced US were performed to determine the absence or presence of vascularization. Avascular lesions were defined as benign. Histopathologic results or follow-up examinations served as reference standards. Correct classification rate, sensitivity, specificity, and likelihood ratio were calculated. Results Of 55 testicular lesions, 43 (78.2%) were benign and 12 (21.8%) were malignant. Single-modality sensitivities and specificities were 66.7% and 88.4% for color Doppler US, 100% and 76.7% for contrast-enhanced US, and 100% and 72.1% for strain elastography, respectively. Among 12 malignant lesions, color Doppler US failed to demonstrate vascularization in four (33.3%) lesions, which were positive for cancer at contrast-enhanced US. By combining strain elastography and contrast-enhanced US, a sensitivity of 100% and specificity of 93.0% were achieved in differentiating benign and malignant focal testicular lesions. Positive likelihood ratio was 5.7 for color Doppler US, 4.3 for contrast-enhanced US, 3.6 for strain elastography, 14.3 for strain elastography combined with color Doppler US, and 14.3 for strain elastography combined with contrast-enhanced US. Conclusion Multiparametric US allows for a reliable differentiation of benign and malignant intratesticular lesions and can potentially be useful in deciding whether orchiectomy can be replaced with follow-up or less invasive organ-sparing strategies. ^© RSNA, 2017.

Multiparametric Sonography of Hematologic Malignancies of the Testis: Grayscale, Color Doppler, and Contrast-Enhanced Ultrasound and Strain Elastographic Appearances With Histologic Correlation

Primary testicular lymphoma is rare and appears with nonspecific findings on grayscale and color Doppler sonography. We present 8 patients further examined with contrast-enhanced sonography, strain elastography, and histologic analysis after orchiectomy. Seven of 8 patients had a diagnosis of large B-cell lymphoma, and 1 of 8 had a diagnosis of granulocytic sarcoma, with solitary lesions (2 of 8), multiple lesions (3 of 8), or entire testicular involvement (3 of 8). Lesions appeared hypoechoic (7 of 8) or isoechoic (1 of 8), all with increased vascularity on color Doppler sonography and a nonbranching linear pattern of intratumoral vessels (7 of 8). Contrast-enhanced ultrasound (CEUS) confirmed this pattern and showed increased enhancement in all lesions. On strain elastography, all lesions were hard, with an elasticity score of greater than 4. Multiparametric sonography of testicular lymphoma identifies increased vascularity on color Doppler and contrast-enhanced ultrasound and increased lesion stiffness on strain elastography.

Diagnostic value of qualitative and strain ratio elastography in the differential diagnosis of non-palpable testicular lesions

The purpose of this study was to evaluate prospectively the accuracy of qualitative and strain ratio elastography (SE) in the differential diagnosis of non‐palpable testicular lesions. The local review board approved the protocol and all patients gave their consent. One hundred and six patients with non‐palpable testicular lesions were consecutively enrolled. Baseline ultrasonography (US) and SE were correlated with clinical and histological features and ROC curves developed for diagnostic accuracy. The non‐palpable lesions were all ≤1.5 cm; 37/106 (34.9%) were malignant, 38 (35.9%) were benign, and 31 (29.2%) were non‐neoplastic. Independent risk factors for malignancy were as follows: size (OR 17.788; p = 0.002), microlithiasis (OR 17.673, p < 0.001), intralesional vascularization (OR 9.207, p = 0.006), and hypoechogenicity (OR, 11.509, p = 0.036). Baseline US had 89.2% sensitivity (95% CI 74.6–97.0) and 85.5% specificity (95% CI 75.0–92.8) in identifying malignancies, and 94.6% sensitivity (95% CI 86.9–98.5) and 87.1% specificity (95% CI 70.2–96.4) in discriminating neoplasms from non‐neoplastic lesions. An elasticity score (ES) of 3 out of 3 (ES3, maximum hardness) was recorded in 30/37 (81.1%) malignant lesions (p < 0.001). An intermediate score of 2 (ES2) was recorded in 19/38 (36.8%) benign neoplastic lesions and in 22/31 (71%) non‐neoplastic lesions (p = 0.005 and p = 0.001 vs. malignancies). None of the non‐neoplastic lesions scored ES3. Logistic regression analysis revealed a significant association between ES3 and malignancy (χ² = 42.212, p < 0.001). ES1 and ES2 were predictors of benignity (p < 0.01). Overall, SE was 81.8% sensitive (95% CI 64.8–92.0) and 79.1% specific (95% CI 68.3–88.4) in identifying malignancies, and 58.6% sensitive (95% CI 46.7–69.9) and 100% specific (95% CI 88.8–100) in discriminating non‐neoplastic lesions. Strain ratio measurement did not improve the accuracy of qualitative elastography. Strain ratio measurement offers no improvement over elastographic qualitative assessment of testicular lesions; testicular SE may support conventional US in identifying non‐neoplastic lesions when findings are controversial, but its added value in clinical practice remains to be proven.

Real-Time Elastography and Contrast-Enhanced Ultrasonography in the Evaluation of Testicular Masses: A Comparative Prospective Study

This study investigates the usefulness of contrast-enhanced ultrasound (CEUS) and real-time elastography (RTE) for the characterization of testicular masses by comparing pre-operative ultrasound findings with post-operative histology. Sixty-seven patients with 68 sonographically detected testicular masses underwent B-mode, color-coded Doppler sonography (CCDS), CEUS and RTE according to defined criteria. For RTE, elasticity score (ES), difference of elasticity score (D-ES), strain ratio (SR) and size quotient (Qsize) were evaluated. Histopathologically, 54/68 testicular lesions were neoplastic (47 malignant, 7 benign). Descriptive statistics revealed the following results (neoplastic vs. non-neoplastic) for sensitivity, specificity, positive predictive value, negative predictive value and accuracy, respectively: B-mode, 100%, 43%, 87%, 100%, 88%; CCDS 81%, 86%, 96%, 55%, 82%; CEUS 93%, 85%, 96%, 73%, 91%; ES 98%, 25%, 85%, 75%, 85%; D-ES 98%, 50%, 90%, 83%, 89%; SR 90%, 45%, 86%, 56%, 81%; and Qsize 57%, 83%, 94%, 28%, 61%. B-mode with CCDS remains the standard for assessing testicular masses. In characterization of testicular lesions, CEUS clearly outperformed all other modalities. Our study does not support the routine use of RTE in testicular ultrasonography because of its low specificity.

Straight Vessel Pattern and Rapid Filling Time: Characteristic Findings on Contrast-Enhanced Sonography of Testicular Lymphoma

Six patients with 7 lesions that were histologically confirmed as primary testicular lymphoma were preoperatively investigated with a standardized sonographic protocol including contrast-enhanced sonography. Duplex and contrast-enhanced sonography showed marked hypervascularization in all 7 lesions. On contrast-enhanced sonography, the filling time of lymphomatous lesions was significantly shorter than the filling time of a size-matched sample of 10 patients with seminomas (P < .0001). The sonographic hallmarks of testicular lymphoma in our case series were as follows: (1) sharply demarcated homogeneous hypoechoic testicular lesions with marked hypervascularization; (2) a rapid (<7 seconds) filling time of contrast bubbles; and (3) a straight and parallel course of intralesional vessels on contrast-enhanced sonography.

Colour Doppler and ultrasound characteristics of testicular Leydig cell tumours

OBJECTIVE

To assess the colour Doppler and ultrasound features of testicular Leydig cell tumours (LCTs) in a population of 38 surgically proven lesions.

METHODS

From August 2008 to March 2015, we retrospectively included 38 surgically proven LCTs in 36 patients. Clinical data, scrotal colour Doppler, B-mode ultrasound and videos images were reviewed for each patient. The volume, echotexture of the testis, size, shape, echogenicity and the vascularization pattern of the lesion were evaluated. The tumour margins were categorized as either smooth or lobulated. The vascularization was classified as intense, moderate or without any hypervascularization. We defined the vascularization pattern groups as central, peripheral and mixed (the latter meaning both central and peripheral).

RESULTS

26 patients were referred for infertility [5 patients were subsequently diagnosed with Klinefelter syndrome (KS) and 5 patients with cryptorchidism]. 28 patients underwent testis-sparing surgery, while 8 patients underwent a radical orchiectomy. The LCTs were mostly infracentimetric (68.4%), with a median size of 7.0 mm (ranging from 4.0 to 11 mm). 50% of the lesions had lobulated margins, and these were significantly larger than the smooth lesions (p < 0.05). The content of the lesions was markedly homogeneous and hypoechoic. All lesions had sharp demarcations from the adjacent pulp. 36/38 lesions exhibited moderate-to-intense hypervascularization, with a mixed intrinsic and peripheral rim pattern. Larger lesions were more hypervascularized (p < 0.05). LCTs in patients with KS had atypical features.

CONCLUSION

Typical sporadic LCTs appeared as isolated hypoechoic, infracentimetric masses, with a clear demarcation from the adjacent pulp. They presented intrinsic and peripheral rim hypervascularization.

ADVANCES IN KNOWLEDGE

By undertaking the largest imaging series of LCT to date (to our knowledge), we reassessed the typical sonographical aspects of LCTs, so as to provide guidance in regard to opting for testis-sparing surgery and for follow-up. LCTs present both intrinsic and rim vascularization detectable by colour Doppler ultrasound. Intrinsic vascularization and lobulated margins are common findings in testicular LCTs.

Quantification of carotid plaque elasticity and intraplaque neovascularization using contrast-enhanced ultrasound and image registration-based elastography

It is valuable for evaluation of carotid plaque vulnerability to investigate the relation between intraplaque neovascularization (IPN) and plaque elasticity. The contrast-enhanced ultrasound (CEUS) has been used in IPN measurement, but it cannot assess plaque elasticity. The aim of this study was to develop an ultrasound elastography technique based on registration of CEUS sequential images and to use this technique for direct comparison between IPN and plaque elasticity. We employed a nonrigid image registration method using the free-form deformation model to register a pair of clinical CEUS images at systole and diastole. The 2D displacement field of the plaque was estimated and then utilized to calculate the axial and lateral strain distributions within the plaque, from which quantitative strain parameters were obtained. The IPN was measured semiquantitatively with visual assessment and quantitatively with the time-intensity curve analysis and the analysis of contrast agent spatial distributions. Histopathology with CD34 staining for quantification of microvessel density (MVD) was performed on plaques excised by carotid endarterectomy. Simulation experiments showed that the mean absolute error and the root mean squared error of the displacement estimation were 0.325±0.180 pixel (7.2%±3.8%) and 0.556±0.284 pixel (12.3%±6.1%), respectively, demonstrating high accuracy of the elastography technique. Thirty-eight plaques in 29 patients met the inclusion criteria for the elastography and image analysis, where ten plaques underwent endarterectomy. The 95th percentile (A95) and standard deviation (Asd) of the axial strains exhibited significant differences between the low and high grades of IPN visually assessed (p<0.01). A95 (R=0.579; p<0.001) and Asd (R=0.609; p<0.001) were correlated with the enhanced intensity of plaque, and also correlated with the MVD (R=0.793 and 0.817, respectively; p<0.01), suggesting that plaque became softer and more elastically heterogeneous as IPN increased. These findings provide direct and quantitative evidence for the associations between plaque strains and IPN and might be helpful for evaluation of carotid plaque vulnerability and for plaque risk stratification.

Growing indications for CEUS: The kidney, testis, lymph nodes, thyroid, prostate, and small bowel

Contrast enhanced ultrasonography (CEUS) is increasingly used for non-hepatic applications as well, so that nearly all organs have been investigated. Among them, there is a growing clinical use for a variety of pathologies of the kidney, testis, and small bowel. The possibility to differentiate benign from malignant nodes in cancer patients has been investigated. A new application is in the detection of sentinel nodes after intradermal microbubble injection. The need to distinguish thyroid nodules eligible for fine needle aspiration cytology has led to the use of CEUS in thyroid examinations as well. The potential of CEUS for prostate cancer detection has been extensively investigated, with encouraging initial results. Early promise, however, has not been fulfilled. New perspective regards evaluation of the extent of prostate tissue devascularization following ablative treatments.