Skip to main content
Erschienen in: Current Urology Reports 9/2023

Open Access 27.06.2023

Imaging Techniques to Differentiate Benign Testicular Masses from Germ Cell Tumors

verfasst von: Ava Saidian, Aditya Bagrodia

Erschienen in: Current Urology Reports | Ausgabe 9/2023

Abstract

Purpose of Review

To discuss role of different diagnostic imaging modalities in differentiation of benign testicular masses from seminomatous germ cell tumors (SGCTs) and non-seminomatous GCTs (NSGCTs).

Recent Findings

New modalities of ultrasonography, including contrast enhancement and shear wave elastography, may help differentiate between benign and malignant intratesticular lesions.

Summary

Ultrasonography remains the recommended imaging modality for initial evaluation of testicular masses. However, MRI can be used to better define equivocal testicular lesions on US.
Hinweise

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Introduction

Testicular germ cell tumors (GCTs) are a rare malignancy with peak incidence in men aged 20 to 34 years [1]. Disease staging is critical in deciding treatment choice and sequence of treatments as more than 90% of testicular GCTs are considered curable. Testicular cancer staging includes a combination of tumor histopathology, assessment of lymph nodes and metastases on diagnostic imaging, and serum tumor markers [2••]. A scrotal mass with suspicion for testicular GCT is evaluated with physical exam, testicular ultrasound, and serum tumor markers. Accurate characterization of scrotal lesions is important as the management can range from observation to surgical resection. A missed diagnosis of a testicular germ cell tumor can lead to delays in diagnosis, advanced stage at presentation, treatment intensification, and worse clinical outcomes. Conversely, unnecessary orchiectomy for benign scrotal pathology can negatively affect androgen function, fertility parameters, and body image. Accordingly, it is paramount that we can distinguish benign from malignant testicular lesions.
This article reviews the role of different diagnostic imaging modalities in differentiation of benign testicular masses from seminomatous (SGCTs) and non-seminomatous GCTs (NSGCTs).

Ultrasonography (US)

B-mode high-frequency (greater than or equal to 10 MHz) grayscale scrotal sonography performed with a linear-array transducer is the initial imaging modality used to evaluate testicular masses suspicious for malignancy. GCTs are often intratesticular masses, and US can accurately distinguish between intratesticular and extratesticular lesions [3]. SGCTs appear hyperechoic and homogenous compared with healthy testicular tissues. They may be lobulated or multinodular and rarely have calcifications (30%) or cystic spaces (10%) [4]. NSGTs often appear as multicomponent masses on grayscale sonography and can be solid or solid-cystic lesions [5•]. Color-coded duplex sonography can be used to analyze the vascularization of intratesticular masses with malignant lesions often demonstrating increased vascularity compared with background testis tissue [4]. Grayscale US (combined with clinical presentation) can be used to distinguish between GCTs and benign testicular masses such as testicular hematoma, epidermoid cyst, adrenal rests, splenogonadal fusion, and sex-cord stromal tumors (Table 1).
Table 1
Imaging features of benign masses on US and MRI
Lesion
Clinical feature
Imaging features
US
Imaging features
MRI
Testicular hematoma
Recent trauma
Avascular, iso- to hyperechoic, become hypoechoic over time
Hyperintense initially on T1, hypointense rim on T2 over time; no contrast enhancement
Epidermoid cyst
Painless mass
Well-defined rounded lesions with onion ring internal pattern of echoes
Absence of contrast enhancement; T1 hypointensity, T2 hyperintensity with hypointense rim
Adrenal rest
Often in patients with CAH
Hypoechoic, bilateral
Contrast enhancement, low T2 signal intensity
Splenogonadal fusion
Painless mass
Splenic tissue is hypoechoic, often with central vascular pattern with vessels branching towards periphery
May show continuous or discontinuous relation between ectopic splenic tissue and gonad
Sex-cord stromal
Precocious puberty, gynecomastia
Focal hypoechoic mass
Low T2 signal intensity; mild contrast enhancement
Lipoma
Painless mass
Hypoechoic, homogenous
High T1 signal intensity
Testicular cyst
Non-palpable, discovered incidentally
Anechoic with posterior acoustic enhancement; well-marginated
Lack contrast enhancement or solid components
Shear wave elastography (SWE) is an US modality that provides quantitative color-coded maps of tissues stiffness that are displayed in real time with B-mode images through a detection pulse that measures the speed of shear waves through the tissue of interest [6].
Pedersen et al. compared testicular stiffness in normal testicular tissue (n = 130), testicular microlithiasis (n = 99), and GCTs (n = 19) using SWE. Their analysis revealed significantly higher mean velocity on SWE in the testicular cancer group compared to those with normal testicular tissue and testicular microlithiasis (p < 0.001) [7]. Rocher et al. evaluated the performance of combined B-mode, color doppler, and SWE US in distinguishing between benign and malignant testicular lesions. Their evaluation included 89 focal testicular masses with patients categorized by pathology: malignant tumors (SGCTs, NSGCTs, malignant sex cord Sertoli cell tumor (n = 1), and myeloma (n = 1)), burned-out tumors, and benign lesions. The following five parameters using SWE were recorded for each testicular lesion: average stiffness with standard deviation (SD), max stiffness, average stiffness/normal testicular tissue stiffness ratio, and max stiffness/normal testicular tissue stiffness ratio. The most relevant conventional US and SWE parameters that best discriminated malignant tumors and burned-out tumors from benign lesions were peripheral vascularization, grouped microliths, and max stiffness/normal testicular tissue stiffness ratio with 92% sensitivity, 96% specificity, 94% accuracy (p < 10−4), and area under the receiver operating characteristic curve (AUROC) ± 95% confidence interval (CI) of 0.98 ± 0.20. Without the SWE parameters, conventional US had 55% sensitivity, 97% specificity, 74% accuracy (p < 10−4), and AUROC ± 95% CI of 0.88 ± 0.11. Their group concluded that SWE combined with color doppler US and B-mode US can significantly improve characterization of testicular masses, however, their study was limited by use of a single US operator and subjectivity of the conventional US parameters [7, 8•].
Another method of ultrasonography with potential to help distinguish between benign and testicular GCTs is contrast-enhanced US (CEUS). A bolus of contrast material (microbubbles) is introduced intravenously during simultaneous US of the testicle to demonstrate tissue perfusion. Isidori et al. performed unenhanced and CEUS on 115 patients with non-palpable testicular lesions who subsequently underwent surgical resection. The rapidity of wash-in and washout were the CEUS parameters that best differentiated malignant and benign tumors. Combination of unenhanced and CEUS was highly accurate in diagnosing testicular malignancies (AUROC 0.927 with 95% CI [0.827, 0.981]) [9]. CEUS has yet to be widely validated in the USA and is not routinely used in testicular US.

Magnetic Resonance Imaging

MRI is not routinely used in the initial evaluation of testicular masses but can be a helpful diagnostic adjunct when US findings are equivocal or if the exact location of an intrascrotal mass is difficult to distinguish. MRI has multiple modalities which are unique in evaluating testicular tumor features. T1- and T2-weighted characteristics can differentiate between fat, soft tissue, and fluid; T1 pre- and post-contrast sequences can assess tumor enhancement; and diffusion-weighted imaging (DWI) can assess water restriction in tissues highlighting neoplastic tissues [10].
Dynamic contrast-enhanced (DCE) MRI obtains information regarding tissue perfusion through the analysis of tissue temporal reaction to the inflow of contrast. More specifically, DCE-MRI provides quantifiable parameters of tissue perfusion, vessel permeability, and microvascular status [11]. Tsili et al. retrospectively studied imaging findings of 44 men who underwent DCE-MRI for intratesticular lesion evaluation. Time-signal intensity curves were plotted for normal testicular tissue and intratesticular lesions. They found that enhancement over time followed one of three curve shapes: type I was a linear increase of contrast enhancement, type II presented as an initial upstroke followed by a plateau or gradual increase, and type III showed an initial stroke-up followed by washout of contrast. Normal testicular tissue enhancement followed a type I curve (100% of cases). Benign intratesticular lesions enhanced with a type II curve (63.6% of benign cases) and testicular carcinomas enhanced heterogeneously with a type III curve (100% of cases) (p < 0.001) [12].
DWI is an MRI sequence that provides the functional information regarding tissue diffusion properties. Qualitatively, diffusion is seen on trace images and quantitatively represented on apparent diffusion coefficient (ADC) maps. Malignant tissue, for example, has restricted tissue diffusion due to the increased intracellular proportion of water compared to the extracellular compartment; therefore, it will be bright on trace images and hypointense on the ADC map [13]. A review of 31 scrotal lesions found that the ADC values of normal testis and benign intratesticular lesions were significantly different from testicular malignancies (p < 0.05), suggesting that DWI MRI with measurement of ADC may be helpful in characterizing intratesticular masses [14].
Despite these sequences, GCTs can be difficult to distinguish from stromal tumors as they both can appear homogenous with T2-weighted hypointensity and T1 isointesity [15, 16]. Given the paucity of evidence for MRI to differentiate between malignant and benign testicular tumors, its use is recommended for ambiguous cases of testicular lesions, planning for testis-sparing surgery and/or to differentiate between intratesticular and paratesticular lesions [17••, 18].
More specifically, MRI can be used to confirm diagnosis of fatty masses, cystic lesions, and benign solid tumors that are indeterminate on US. Lipomas have high T1 signal intensity on MRI that is specific to adipose tissue but appear non-specifically homogenous and hyperechoic on US [19, 20]. Testicular cysts, which can occasionally appear complex on US, may need an MRI to ensure there are no solid or contrast enhancing components concerning for a cystic testicular neoplasm [21] (Table 1).

Conclusion

Imaging plays a crucial role in evaluating scrotal masses with ultrasound being the preferred primary imaging modality. The advancement of sonographic technology, CEUS and SWE, has provided clinicians tools that go beyond simple grayscale imaging to help more accurately characterize intratesticular lesions as benign or malignant. When sonography is equivocal, MRI of the scrotum can serve as a supplemental imaging modality to aid in diagnosis and management of an intratesticular lesion.

Compliance with Ethical Standards

Conflict of Interest

The authors have no conflicts of interest to disclose.

Human and Animal Rights and Informed Consent

This article does not contain any studies with human or animal subjects performed by any of the authors.
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://​creativecommons.​org/​licenses/​by/​4.​0/​.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Unsere Produktempfehlungen

e.Med Interdisziplinär

Kombi-Abonnement

Für Ihren Erfolg in Klinik und Praxis - Die beste Hilfe in Ihrem Arbeitsalltag

Mit e.Med Interdisziplinär erhalten Sie Zugang zu allen CME-Fortbildungen und Fachzeitschriften auf SpringerMedizin.de.

e.Med Gynäkologie

Kombi-Abonnement

Mit e.Med Gynäkologie erhalten Sie Zugang zu CME-Fortbildungen der beiden Fachgebiete, den Premium-Inhalten der Fachzeitschriften, inklusive einer gedruckten gynäkologischen oder urologischen Zeitschrift Ihrer Wahl.

e.Med Urologie

Kombi-Abonnement

Mit e.Med Urologie erhalten Sie Zugang zu den urologischen CME-Fortbildungen und Premium-Inhalten der urologischen Fachzeitschriften.

Literatur
2.
Zurück zum Zitat •• Thomas KL, et al. The role of diagnostic imaging in the primary testicular cancer: initial staging, response assessment and surveillance. Transl Androl Urol. 2020;9(Suppl 1):S3–S13. A comprehensive review of different imaging modalities in not only primary assessment, but also staging and response assessment in primary testicular cancer. •• Thomas KL, et al. The role of diagnostic imaging in the primary testicular cancer: initial staging, response assessment and surveillance. Transl Androl Urol. 2020;9(Suppl 1):S3–S13. A comprehensive review of different imaging modalities in not only primary assessment, but also staging and response assessment in primary testicular cancer.
3.
Zurück zum Zitat Rifkin MD, et al. Diagnostic capabilities of high-resolution scrotal ultrasonography: prospective evaluation. J Ultrasound Med. 1985;4(1):13–9.CrossRefPubMed Rifkin MD, et al. Diagnostic capabilities of high-resolution scrotal ultrasonography: prospective evaluation. J Ultrasound Med. 1985;4(1):13–9.CrossRefPubMed
4.
Zurück zum Zitat Marko J, et al. Testicular seminoma and its mimics: from the radiologic pathology archives. Radiographics. 2017;37(4):1085–98.CrossRefPubMed Marko J, et al. Testicular seminoma and its mimics: from the radiologic pathology archives. Radiographics. 2017;37(4):1085–98.CrossRefPubMed
5.
Zurück zum Zitat • Necas, M, Muthupalaniappaan M, Barnard C. Ultrasound morphological patterns of testicular tumours, correlation with histopathology. J Med Radiat Sci. 2021;68(1):21–7. Well-designed study correlating US appearance of testicular tumors to histopathology. • Necas, M, Muthupalaniappaan M, Barnard C. Ultrasound morphological patterns of testicular tumours, correlation with histopathology. J Med Radiat Sci. 2021;68(1):21–7. Well-designed study correlating US appearance of testicular tumors to histopathology.
6.
Zurück zum Zitat Bercoff J, Tanter M, Fink M. Supersonic shear imaging: a new technique for soft tissue elasticity mapping. IEEE Trans Ultrason Ferroelectr Freq Control. 2004;51(4):396–409.CrossRefPubMed Bercoff J, Tanter M, Fink M. Supersonic shear imaging: a new technique for soft tissue elasticity mapping. IEEE Trans Ultrason Ferroelectr Freq Control. 2004;51(4):396–409.CrossRefPubMed
7.
Zurück zum Zitat Pedersen MR, et al. Comparison of tissue stiffness using shear wave elastography in men with normal testicular tissue, testicular microlithiasis and testicular cancer. Ultrasound Int Open. 2017;3(4):E150–5.CrossRefPubMedPubMedCentral Pedersen MR, et al. Comparison of tissue stiffness using shear wave elastography in men with normal testicular tissue, testicular microlithiasis and testicular cancer. Ultrasound Int Open. 2017;3(4):E150–5.CrossRefPubMedPubMedCentral
8.
Zurück zum Zitat • Rocher L, et al. Characterization of testicular masses in adults: performance of combined quantitative shear wave elastography and conventional ultrasound. Ultrasound Med Biol. 2019;45(3):720–31. Evaluation of shear wave elastography combined with conventional US as a practical technique to evaluate testicular masses. • Rocher L, et al. Characterization of testicular masses in adults: performance of combined quantitative shear wave elastography and conventional ultrasound. Ultrasound Med Biol. 2019;45(3):720–31. Evaluation of shear wave elastography combined with conventional US as a practical technique to evaluate testicular masses.
9.
Zurück zum Zitat Isidori AM, et al. Differential diagnosis of nonpalpable testicular lesions: qualitative and quantitative contrast-enhanced US of benign and malignant testicular tumors. Radiology. 2014;273(2):606–18.CrossRefPubMed Isidori AM, et al. Differential diagnosis of nonpalpable testicular lesions: qualitative and quantitative contrast-enhanced US of benign and malignant testicular tumors. Radiology. 2014;273(2):606–18.CrossRefPubMed
10.
Zurück zum Zitat Mittal PK, et al. Spectrum of extratesticular and testicular pathologic conditions at scrotal MR imaging. Radiographics. 2018;38(3):806–30.CrossRefPubMed Mittal PK, et al. Spectrum of extratesticular and testicular pathologic conditions at scrotal MR imaging. Radiographics. 2018;38(3):806–30.CrossRefPubMed
11.
Zurück zum Zitat Gordon Y, et al. Dynamic contrast-enhanced magnetic resonance imaging: fundamentals and application to the evaluation of the peripheral perfusion. Cardiovasc Diagn Ther. 2014;4(2):147–64.PubMedPubMedCentral Gordon Y, et al. Dynamic contrast-enhanced magnetic resonance imaging: fundamentals and application to the evaluation of the peripheral perfusion. Cardiovasc Diagn Ther. 2014;4(2):147–64.PubMedPubMedCentral
12.
Zurück zum Zitat Tsili AC, et al. Dynamic contrast-enhanced subtraction MRI for characterizing intratesticular mass lesions. AJR Am J Roentgenol. 2013;200(3):578–85.CrossRefPubMed Tsili AC, et al. Dynamic contrast-enhanced subtraction MRI for characterizing intratesticular mass lesions. AJR Am J Roentgenol. 2013;200(3):578–85.CrossRefPubMed
14.
15.
Zurück zum Zitat Kim W, et al. US MR imaging correlation in pathologic conditions of the scrotum. Radiographics. 2007;27(5):1239–53. Kim W, et al. US MR imaging correlation in pathologic conditions of the scrotum. Radiographics. 2007;27(5):1239–53.
16.
Zurück zum Zitat Tsili AC, et al. Diffusion-weighted magnetic resonance imaging in the characterization of testicular germ cell neoplasms: effect of ROI methods on apparent diffusion coefficient values and interobserver variability. Eur J Radiol. 2017;89:1–6.CrossRefPubMed Tsili AC, et al. Diffusion-weighted magnetic resonance imaging in the characterization of testicular germ cell neoplasms: effect of ROI methods on apparent diffusion coefficient values and interobserver variability. Eur J Radiol. 2017;89:1–6.CrossRefPubMed
17.
Zurück zum Zitat •• Stephenson A, et al. Diagnosis and treatment of early stage testicular cancer: AUA guideline. J Urol. 2019;202(2):272–81. Current guidelines for initial stagingof testicular malignancies. •• Stephenson A, et al. Diagnosis and treatment of early stage testicular cancer: AUA guideline. J Urol. 2019;202(2):272–81. Current guidelines for initial stagingof testicular malignancies.
18.
Zurück zum Zitat Albers P, et al. EAU guidelines on testicular cancer: 2011 update. European Association of Urology. Actas Urol Esp. 2012;36(3):127–45. Albers P, et al. EAU guidelines on testicular cancer: 2011 update. European Association of Urology. Actas Urol Esp. 2012;36(3):127–45.
19.
Zurück zum Zitat Akbar SA, et al. Multimodality imaging of paratesticular neoplasms and their rare mimics. Radiographics. 2003;23(6):1461–76.CrossRefPubMed Akbar SA, et al. Multimodality imaging of paratesticular neoplasms and their rare mimics. Radiographics. 2003;23(6):1461–76.CrossRefPubMed
20.
Zurück zum Zitat Hertzberg BS, et al. Sonography of an intratesticular lipoma. J Ultrasound Med. 1985;4(11):619–21. Hertzberg BS, et al. Sonography of an intratesticular lipoma. J Ultrasound Med. 1985;4(11):619–21.
21.
Metadaten
Titel
Imaging Techniques to Differentiate Benign Testicular Masses from Germ Cell Tumors
verfasst von
Ava Saidian
Aditya Bagrodia
Publikationsdatum
27.06.2023
Verlag
Springer US
Erschienen in
Current Urology Reports / Ausgabe 9/2023
Print ISSN: 1527-2737
Elektronische ISSN: 1534-6285
DOI
https://doi.org/10.1007/s11934-023-01172-7

Weitere Artikel der Ausgabe 9/2023

Current Urology Reports 9/2023 Zur Ausgabe

„Überwältigende“ Evidenz für Tripeltherapie beim metastasierten Prostata-Ca.

22.05.2024 Prostatakarzinom Nachrichten

Patienten mit metastasiertem hormonsensitivem Prostatakarzinom sollten nicht mehr mit einer alleinigen Androgendeprivationstherapie (ADT) behandelt werden, mahnt ein US-Team nach Sichtung der aktuellen Datenlage. Mit einer Tripeltherapie haben die Betroffenen offenbar die besten Überlebenschancen.

„Übersichtlicher Wegweiser“: Lauterbachs umstrittener Klinik-Atlas ist online

17.05.2024 Klinik aktuell Nachrichten

Sie sei „ethisch geboten“, meint Gesundheitsminister Karl Lauterbach: mehr Transparenz über die Qualität von Klinikbehandlungen. Um sie abzubilden, lässt er gegen den Widerstand vieler Länder einen virtuellen Klinik-Atlas freischalten.

Alphablocker schützt vor Miktionsproblemen nach der Biopsie

16.05.2024 alpha-1-Rezeptorantagonisten Nachrichten

Nach einer Prostatabiopsie treten häufig Probleme beim Wasserlassen auf. Ob sich das durch den periinterventionellen Einsatz von Alphablockern verhindern lässt, haben australische Mediziner im Zuge einer Metaanalyse untersucht.

Klinikreform soll zehntausende Menschenleben retten

15.05.2024 Klinik aktuell Nachrichten

Gesundheitsminister Lauterbach hat die vom Bundeskabinett beschlossene Klinikreform verteidigt. Kritik an den Plänen kommt vom Marburger Bund. Und in den Ländern wird über den Gang zum Vermittlungsausschuss spekuliert.

Update Urologie

Bestellen Sie unseren Fach-Newsletter und bleiben Sie gut informiert.