MR imaging of scrotum

Diffusion tensor imaging and fiber tractography of the normal epididymis

PURPOSE

To evaluate the feasibility of diffusion tensor imaging (DTI) and fiber tractography (FT) of the normal epididymis and to determine normative apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values.

METHODS

Twenty-eight healthy volunteers underwent MRI of the scrotum, including DTI on a 3.0 T system. For each anatomic part of the epididymis (head, body and tail) free-hand regions of interest were drawn and the mean ADC and FA were measured by two radiologists in consensus. Parametric statistical tests were used to determine intersubject differences in ADC and FA between the anatomic parts of each normal epididymis and between bilateral epididymides. Fiber tracts of the epididymis were reconstructed using the MR Diffusion tool.

RESULTS

The mean ADC and FA of the normal epididymis was 1.31 × 10-3 mm2/s and 0.20, respectively. No differences in ADC (p = 0.736) and FA (p = 0.628) between the anatomic parts of each normal epididymis were found. Differences (p = 0.020) were observed in FA of the body between the right and the left epididymis. FT showed the fiber tracts of the normal epididymis. Main study's limitations include the following: small number of participants with narrow age range, absence of histologic confirmation and lack of quantitative assessment of the FT reconstructions.

CONCLUSION

DTI and FT of the normal epididymis is feasible and allow the noninvasive assessment of the structural and geometric organization of the organ.

A case of intrascrotal extratesticular schwannoma

Schwannomas are benign tumors arising from Schwann cells, which compose the myelin sheath covering peripheral nerves. Although schwannomas can develop in various locations throughout the human body, the scrotum is a rare site for development of a schwannoma. Furthermore, to the best of our knowledge, no study to date has focused on the detailed imaging findings of intrascrotal schwannoma.

An Overview of the Role of Multiparametric MRI in the Investigation of Testicular Tumors

Simple Summary

Although conventional ultrasonography remains the primary imaging modality for the assessment of testicular tumors, multiparametric MRI of the scrotum, which combines morphologic and functional data, serves as a powerful adjunct. Based on the recommendations issued by the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology, scrotal MRI is strongly recommended after equivocal US findings. In cases of testicular masses, the main clinical indications are as follows: lesion characterization when sonographic findings are non-diagnostic, discrimination between germ-cell and non-germ-cell testicular tumors, local staging of testicular tumors in patients who are candidates for testis-sparing surgery, and preoperative histological characterization of testicular germ-cell tumors in selected cases. This article aims to provide an overview of the role of multiparametric MRI in the investigation of testicular tumors.

Abstract

Conventional ultrasonography represents the mainstay of testis imaging. In cases in which ultrasonography is inconclusive, scrotal MRI using a multiparametric protocol may be used as a useful problem-solving tool. MRI of the scrotum is primarily recommended for differentiating between benign and malignant testicular masses when sonographic findings are ambiguous. This technique is also accurate in the preoperative local staging of testicular tumors and, therefore, is recommended in patients scheduled for testis-sparing surgery. In addition, MRI may provide valuable information regarding the histological characterization of testicular germ-cell tumors, in selected cases. Scrotal MRI may also help in the differentiation between testicular germ-cell neoplasms and non-germ-cell neoplasms. Axial T1-weighted imaging, axial and coronal T2-weighted imaging, axial diffusion-weighted imaging, and coronal subtracted dynamic contrast-enhanced imaging are the minimum requirements for scrotal MRI. A variety of MRI techniques—including diffusion tensor imaging, magnetization transfer imaging, proton MR spectroscopy, volumetric apparent diffusion coefficient histogram analysis, and MRI-based radiomics—are being investigated for testicular mass characterization, providing valuable supplementary diagnostic information. In the present review, we aim to discuss clinical indications for scrotal MRI in cases of testicular tumors, along with MRI findings of common testicular malignancies.

[Magnetic resonance imaging accuracy and utility for testicular cancer diagnosis]

PURPOSE

The purpose of our study is to analyze the imaging findings described in MRI and the histopathologic type of testicular lesions to determine which findings are the best predictors of malignancy.

MATERIALS AND METHODS

Forty six (46) patients with testicular lesions were initially studied with ultrasound (US) and with testicular MRI (tMRI) on a 1.5-T magnet. MRIs were reviewed by a radiologist with 8 years of experience and imaging findings such as the size of the lesion, the signal intensity in T1, T2 weighted sequences, and the enhancement after endovenous contrast administration, were correlated with the histopathologic diagnosis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were analyzed.

RESULTS

The enhancement after administration of contrast was the finding of better performance with a sensitivity, specificity, PPV and NPV of 90 (71-97), 47 (24-71), 74 (56-87) and 73 (40-92), respectively. Meanwhile, the results for hypointense/heterogeneous lesions in T2 weighted sequences and with enhancement with intravenous contrast were 87 (49-84), 47 (44-89), 74 (55-86) y 67 (35-89), respectively.

CONCLUSION

The finding of a testicular lesion of low signal intensity and heterogeneous in T2 weighted sequences, with IV contrast enhancement represents a valuable predictor of malignancy. The latter being the most sensitive as a predictor of malignancy.

Testicular tumors: discriminative value of conventional MRI and diffusion weighted imaging

To explore the feasibility of using conventional MRI features combined with apparent diffusion coefficient (ADC) values for the differential diagnosis of testicular tumors.A total of 63 patients with pathologically confirmed testicular tumors were enrolled in this study. In particular, there were 46 cases of malignant lesions and 17 cases of benign lesions. All patients underwent conventional magnetic resonance imaging (MRI) and diffusion weighted imaging. Multivariate logistic regression models and receiver operating characteristic curves were constructed to assess diagnostic accuracies.T2-homogeneity, intratumoral septa, and peritumoral infiltration were more common in the malignant group, and capsule sign was more common in the benign group (P < .05 for all). The mean ADC value of the malignant group was lower than that of the benign group (P < .05). When the ADC value ≤ 0.90 × 10-3 mm2/s, the diagnosis tended to be malignancy. The conventional MRI model could achieve better diagnostic accuracy than ADC values alone (P < .05). Compared with the conventional MRI model, the specificity and accuracy of the full model (ADC and conventional MRI model) increased by 9.8% and 3.2%, respectively. T2-homogeneity and T2-hypointensity were more common in seminoma and lymphoma, cystic changes were more common in nonseminomatous germ cell tumor (NSGCT), and intratumoral septa was more common in seminoma (P < .05 for all). The ADC value of NSGCT was larger than seminoma, and lymphoma was the smallest (P < .05 for all). Cystic changes, T2-hypointensity, intratumoral septa, and ADC value were independent factors for differentiating the seminoma, NSGCT, and lymphoma subgroups.A combination of conventional MRI features and ADC values can improve the diagnostic efficiency for differentiating benign and malignant testicular tumors, and can additionally distinguish different subtypes of malignant testicular tumors.

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.

When to ask for an MRI of the scrotum

Background

Multiparametric MRI (mpMRI) of the scrotum has been established as a useful second‐line diagnostic tool for the investigation of scrotal diseases. Recently, recommendations on clinical indications for scrotal MRI were issued by the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology.

Objective

To update current research on when to ask for an MRI of the scrotum.

Methods

PubMed database was searched for original articles and reviews published during 2010–2021.

Results

Eighty‐three articles fulfilled the search criteria. Scrotal MRI is mainly recommended after inconclusive US findings or inconsistent with the clinical examination and should be asked in the following cases: differentiation between intratesticular and paratesticular lesions (in rare cases of uncertain US findings), characterization of paratesticular and intratesticular lesions (when US findings are indeterminate), discrimination between germ cell and sex cord‐stromal testicular tumors, local staging of testicular malignancies (in patients planned for testis‐sparing surgery), differentiation between seminomas and non‐seminomatous tumors (when immediate chemotherapy is planned and orchiectomy is delayed), assessment of acute scrotum and scrotal trauma (rarely needed, in cases of non‐diagnostic US findings) and detection and localization of undescended testes (in cases of inconlusive US findings). Although preliminary data show promising results in the evaluation of male infertility, no established role for mpMRI still exists.

Conclusion

Multiparametric MRI of the scrotum, by assessing morphologic and functional data represents a valuable problem‐solving tool, helping to improve our understanding on the nature of scrotal pathology and the process of spermatogenesis. The technique may improve patient care and reduce the number of unnecessary surgical procedures.

Proton MR Spectroscopy in Assessing the Biochemical Milieu of Human Testes

Proton magnetic resonance spectroscopy (MRS), considered a connection between metabolism and anatomic and functional information provided by standard MRI, gives information on various tissue metabolites and their pathologic changes. Recently, proton MRS has been added as an adjunct tool to the multiparametric protocol of scrotal MRI, providing a new insight into the extremely complex biochemical milieu of normal and abnormal testes. This article reviews proton MR spectra of normal testes, showing age and bilateralism dependence. Disturbances of various metabolic pathways in testes of infertile men resulting in alterations of metabolite peaks are discussed. Preliminary data on proton MR spectra of testicular mass lesions are presented. LEVEL OF EVIDENCE: 5. TECHNICAL EFFICACY STAGE: 5.

MRI findings of nonobstructive azoospermia: lesions in and out of pelvic cavity

Nonobstructive azoospermia (NOA) can be caused by various diseases, including congenital disorders, endocrine disorders, infections, tumor or tumor-like diseases, vascular diseases, etc. Diagnosis of the underlying cause of NOA is complicated and challenging. In this study, we introduce an MR examination protocol for the etiological diagnosis of NOA, and demonstrate a series of NOA patients with different causes and imaging findings. Except for lesions of testes, the patients may also combine abnormalities of adrenal glands and central nervous system. In such cases, the patients could benefit from additional abdominal and intracranial scans.

Are there differences in the biochemical profile of bilateral normal testes? A 3.0 T 1H-MR spectroscopy study

Bilateral normal testes asymmetry represents an interesting phenomenon. The aim was to assess possible differences in the biochemical profile of bilateral normal testes by 3.0 T proton magnetic resonance spectroscopy (1H-MRS). Twenty-one men were examined with scrotal 3.0 T MRI, including a single-voxel point-resolved spectroscopy sequence. MR spectra were obtained by placing a volume of interest in the middle of each normal testis. Normalised metabolite concentrations, defined as ratios of the calculated metabolite concentrations relative to creatine (Cr) concentration, were compared between bilateral normal testes using Mann-Whitney U test. 1H-MRS allowed the detection of certain testicular metabolites, including total choline, Cr, myo-inositol, Glx, total lipids and macromolecules resonating at 0.9, 1.3 and 2.0 ppm. Normal left testis had higher median normalised concentrations of Glx (p = .002) and lactate (p = .041) compared with the normal right testis. Differences in concentrations of Glx were attributed to differences in glutamate (p = .020). Normal testes asymmetry is confirmed in this study by differences in the biochemical testicular profile, as assessed by 3.0 T 1H-MRS. Increase in levels of glutamate and lactate in normal left testis should be correlated with changes in metabolic pathways, specifically glycometabolism and amino acid metabolism.

Imaging Modalities in Genitourinary Emergencies

Emergency physicians rely on a multitude of different imaging modalities in the diagnosis of genitourinary emergencies. There are many considerations to be taken into account when deciding which imaging modality should be used first, as oftentimes several diagnostic tools can be used for the same pathologic condition. These factors include radiation exposure, sensitivity, specificity, age of patient, availability of resources, cost, and timeliness of completion. In this review, the strengths and weaknesses of different imaging tools in the evaluation of genitourinary emergencies are discussed.

Testicular epidermoid cysts: a reevaluation

Background

Testicular epidermoid cysts (TECs) are rare benign testicular neoplasms. As TECs are rarely associated with germ cell tumours (GCTs), the understanding of biological behaviour and clinical management of TEC is unresolved.

Methods

We retrospectively searched the files of patients treated for testicular neoplasms and germ cell cancer in the time from 2000 to 2017. Those with TEC were subjected to closer review looking to clinical and histological features, and to results from imaging with ultrasonography (US), contrast enhanced sonography (CEUS) and magnetic resonance imaging (MRI).

Results

Among 589 patients undergoing surgery for testicular tumour, nine simple TECs were identified (1.5, 95% confidence intervals 0.53–2.50%). Median age was 26 years. Imaging revealed sharply demarcated roundish lesions with avascular central areas. Eight patients underwent testis-sparing excision with no recurrence ensuing. One had orchiectomy because of large size of the mass. Histologically, TECs consisted of cornifying squamous cell epithelium and no accompanying germ cell neoplasia in situ. Two additional cases (0.3% of all) required orchiectomy because these TECs were associated with ipsilateral GCT.

Conclusions

TEC is usually a benign lesion that can safely be diagnosed with US, CEUS and MRI due to its roundish shape and its avascular centre. Histologically, this TEC corresponds to the prepubertal-type teratoma unrelated to germ cell neoplasia in situ of the 2016 WHO classification. The other subtype of TEC that is associated with invasive GCT represents a teratoma of postpubertal-type. From a clinical point of view it could be easier to differentiate between a “simple TEC” which is benign (prepubertal type) and a “complex TEC” which is malignant because of its association with invasive GCT.

MRI of testicular malignancies

Although testicular carcinoma represents approximately only 1% of solid neoplasms in men, it is the most common malignancy between young men. The two main histologic categories are testicular germ cell tumors (TGCTs), including seminomas and nonseminomas, accounting for 90-95% of testicular neoplasms and sex cord-stromal tumors. Scrotal MRI, including a multiparametric protocol, has been proposed as a valuable supplemental imaging technique in the investigation of testicular pathology. Recently, the Scrotal and Penile Imaging Working Group appointed by the board of the European Society of Urogenital Radiology has produced recommendations on when to perform scrotal MRI. Regarding intratesticular masses, MRI of the scrotum may be used for their characterization, when US findings are indeterminate and for local staging of TGCTs, when organ-sparing surgery is planned. Differentiation between seminomas and nonseminomas is possible based on MRI features, when clinically needed. Scrotal MRI may also help in differentiating between TGCTs and nongerm cell tumors. Functional information based on diffusion-weighted imaging and dynamic contrast-enhanced MRI data improve testicular mass lesion characterization. Preliminary observations on diffusion tensor imaging, magnetization transfer imaging, and proton MR spectroscopy bring about new data in the understanding of testicular microstructure and pathophysiology.

Sonographically indeterminate scrotal masses: how MRI helps in characterization

Magnetic resonance imaging (MRI) of the scrotum represents a useful supplemental imaging technique in the characterization of scrotal masses, particularly recommended in cases of nondiagnostic ultrasonographic findings. An accurate characterization of the benign nature of scrotal masses, including both intratesticular and paratesticular ones may improve patient management and decrease the number of unnecessary radical surgical procedures. Alternative treatment strategies, including follow-up, lesion biopsy, tumor enucleation, or organ sparing surgery may be recommended. The aim of this pictorial review is to present how MRI helps in the characterization of sonographically indeterminate scrotal masses and to emphasize the key MRI features of benign scrotal masses.

MR Imaging of the Testicular and Extratesticular Tumors: When Do We Need?

Testicular ultrasound is typically the first-line imaging examination in evaluating scrotal pathology. However, MR imaging can often provide valuable additional information, especially when ultrasound and/or clinical examinations are inconclusive. This is particularly evident when encountering testicular or paratesticular lesions, where accurate localization and characterization are paramount for management and prognosis. After reviewing normal scrotal anatomy as seen on MR imaging and offering a sample imaging protocol, the article describes specific indications for scrotal MR imaging and highlights imaging findings unique to various benign and malignant causes.

Imaging of the scrotum: beyond sonography

The aim of this article is to describe the role of second-level imaging techniques after an initial ultrasonography evaluation in the assessment of scrotal diseases. While ultrasonography remains central as the primary imaging modality for the evaluation of pathologic conditions of the scrotum, the role of magnetic resonance imaging continues to evolve: it can actually be valuable as a problem-solving tool when sonographic findings are equivocal or inconclusive. Magnetic resonance imaging of the scrotum may provide accurate detection and characterization of scrotal diseases, well depicting the precise location of scrotal masses (intratesticular or extratesticular) and reliably characterizing benign conditions simulating neoplastic processes, thus preventing unnecessary radical surgery. Advanced magnetic resonance techniques, most of all diffusion weighted imaging and magnetic resonance spectroscopy, play in the meanwhile a more significant role in evaluating scrotal diseases.

TEACHING POINTS

• Multiparametric ultrasonography usually represents the initial imaging modality for approaching scrotal diseases. • MRI is well established as a problem-solving tool for inconclusive sonographic findings. • Advanced MRI techniques can be successfully applied in scrotal pathology assessment. • MRI is valuable in differentiating benign conditions from neoplastic processes. • CT plays a role in trauma assessment and cancer staging alongside PET/CT.

Normal testes asymmetry evaluated by apparent diffusion coefficient and magnetization transfer ratio

Background In humans, the left testis generally hangs lower than the right and the right is larger than the left. Magnetic resonance imaging (MRI) represents an important adjuvant modality in the investigation of testicular diseases. Purpose To assess if normal testes asymmetry is related to apparent diffusion coefficient (ADC) and magnetization transfer ratio (MTR). Material and Methods The normal testes from 106 men were included. Testicular volume (TV) was calculated by using the ellipsoid formula: length × width × height × 0.52. Diffusion-weighted imaging was performed using a SS EPI diffusion pulse sequence and b-values of 0 and 900 s/mm^-2. Magnetization transfer imaging was obtained using a 3D GRE sequence both with and without an off-resonance radiofrequency pulse. MTR maps were obtained by the following formula: (SIo-SIm) / (SIo) × 100%, where SIo and SIm represent the signal intensity in the baseline image and that in the corresponding image acquired with an off-resonance MT pulse, respectively. The mean and standard deviation of testicular volume (TV), ADC, and MTR of both testes was calculated and compared using a paired sample t-test. Results The mean TV (mL) was greater ( P = 0.006) for the right testis (16.77 ± 4.84) compared to the left (15.97 ± 4.45). ADC of the right testis (1.09 ± 0.12 × 10 ^- 3mm²s^-1) was not different ( P = 0.064) from that of the left testis (1.07 ± 0.12 × 10^-3mm²s^-1). Differences ( P = 0.032) were observed between MTR of the right (46.6 ± 2.1%) and left testis (46.0 ± 2.2%). Conclusion The reported differences in paired testes size was confirmed, introducing a possible relationship with structural and functional asymmetry of normal testes, based on MTR.

Magnetic resonance imaging of the scrotum: pictorial review with ultrasound correlation

The purpose of this review is to showcase the added value of scrotal magnetic resonance imaging (MRI) in the workup of neoplastic and non-neoplastic entities. While ultrasound (US) remains the first-line imaging modality for evaluating scrotal pathology, MRI may add valuable information, particularly when US findings are equivocal. The inherent soft tissue resolution characteristics of MRI, as well as the ability to detect subtle enhancement and provide wider field-of-view imaging, can prove useful in evaluating inconclusive US findings. The added value of MR in these instances is critical as it may have a significant impact on patient management.

Potential role of imaging in assessing harmful effects on spermatogenesis in adult testes with varicocele

Varicocele is characterized by an abnormal dilatation and retrograde blood flow in the spermatic veins. Varicocele is the leading correctable cause of male infertility. Although it is highly prevalent in infertile men, it is also observed in individuals with normal fertility. Determining which men are negatively affected by varicocele would enable clinicians to better select those men who will benefit from treatment. To assess the functional status of the testes in men with varicocele, color Doppler sonographic parameters were evaluated. Testicular arterial blood flow was significantly reduced in men with varicocele, reflecting an impairment of spermatogenesis. An improvement in the testicular blood supply was found after varicocelectomy on spectral Doppler analysis. Testicular contrast harmonic imaging and elastography might improve our knowledge about the influence of varicocele on intratesticular microcirculation and tissue stiffness, respectively, providing possible information on the early damage of testicular structure by varicocele. Magnetic resonance imaging (MRI), with measurement of apparent diffusion coefficient has been used to assess the degree of testicular dysfunction and to evaluate the effectiveness of varicocele repair. Large prospective studies are needed to validate the possible role of functional sonography and MRI in the assessment of early defects of spermatogenesis in testes with varicocele.

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.

Magnetic resonance imaging findings of cellular angiofibroma of the tunica vaginalis of the testis: a case report

Background

Cellular angiofibroma represents a rare mesenchymal tumor typically involving the inguinoscrotal area in middle-aged men. Although the origin of this benign tumor is unknown, it is histologically classified as an angiomyxoid tumor. Cellular angiofibroma is characterized by a diversity of pathological and imaging features. An accurate preoperative diagnosis is challenging. Magnetic resonance imaging examination of the scrotum has been reported as a valuable adjunct modality in the investigation of scrotal pathology. The technique by providing both structural and functional information is useful in the differentiation between extratesticular and intratesticular diseases and in the preoperative characterization of the histologic nature of various scrotal lesions. There are few reports in the English literature addressing the magnetic resonance imaging findings of cellular angiofibroma of the scrotum and no reports on functional magnetic resonance imaging data. Here we present the first case of a cellular angiofibroma arising from the tunica vaginalis of the testis and we discuss the value of a multiparametric magnetic resonance protocol, including diffusion-weighted imaging, magnetization transfer imaging and dynamic contrast-enhanced magnetic resonance imaging in the preoperative diagnosis of this rare neoplasm.

Case presentation

A 47-year Greek man presented with a painless left scrotal swelling, which had gradually enlarged during the last 6 months. Magnetic resonance imaging of his scrotum displayed a left paratesticular mass, in close proximity to the tunica vaginalis, with heterogeneous high signal intensity on T2-weighted images and no areas of restricted diffusion. The tumor was hypointense on magnetization transfer images, suggestive for the presence of macromolecules. On dynamic contrast-enhanced magnetic resonance imaging the mass showed intense heterogeneous enhancement with a type II curve. Magnetic resonance imaging findings were strongly suggestive of a benign paratesticular tumor, which was confirmed on pathology following lesion excision.

Conclusions

Magnetic resonance imaging of the scrotum by combining conventional and functional magnetic resonance data provides useful diagnostic information in the preoperative characterization of scrotal masses. A possible diagnosis of a benign paratesticular tumor based on magnetic resonance imaging features may improve patient care and decrease the number of unnecessary radical surgical explorations.

Silicone-induced Penile Sclerosing Lipogranuloma: Magnetic Resonance Imaging Findings

Sclerosing lipogranuloma is a rare benign disease, representing a peculiar granulomatous reaction of fatty tissue. The majority of cases are secondary to injection of exogenous foreign bodies, such as silicone, paraffin, mineral, or vegetable oils. To the best of our knowledge, we present the first case of a silicone-induced penile lipogranuloma in a 52-year-old man evaluated with a multiparametric magnetic resonance imaging (MRI) protocol, including diffusion-weighted imaging, magnetization transfer imaging, and dynamic contrast-enhanced MRI. MRI of the penis by combining both conventional and functional information represents an important imaging tool in the preoperative workup of silicone-induced penile lipogranuloma.

Giant Scrotal Fibrolipoma

Fibrolipoma, an infrequent histological subtype of lipoma, is considered a benign mesenchymal neoplasm. Fibrolipoma of the scrotum is an even more rare entity. We report a case of a 55-year-old male complaining for a slow-growing, painless mass in his left hemis-crotum. Imaging with ultrasonography and magnetic resonance imaging was inconclusive regarding the nature of the tumor and the tumor was excised, sparing the testis. The surgical specimen was a well-defined, yellowish white, solid, and firm mass, measuring 19.5×7×5 cm. There was no cytological atypia or mitosis and no lipoblasts recognized. On immunohistochemistry, MDM2 and CDK4 were not expressed. The histopathology report was fibrolipoma of the scrotum. To the best of our knowledge, this is only the fourth case of fibrolipoma originating from the scrotal components, spermatic cord or testis that has been reported in the English literature.

Multiparametric sonographic imaging of a capillary hemangioma of the testis: appearances on gray-scale, color Doppler, contrast-enhanced ultrasound and strain elastography

We report a case of a lobular capillary hemangioma in a 66-year-old man, who presented with left testicular pain, with an asymptomatic incidental right testicular lesion found on ultrasonography. The sonographic examination demonstrated a heterogeneous mainly iso-echoic intratesticular lesion with marked vascularity on the color Doppler examination. Further evaluation with contrast-enhanced ultrasound and strain elastography was performed; the multiparametric imaging suggested a benign tumor. The multidisciplinary team decision with patient consent was to perform a radical orchiectomy with subsequent histopathology confirming a benign lobular capillary hemangioma.

MR Spectra of Normal Adult Testes and Variations with Age: Preliminary Observations

OBJECTIVES

The aim was to determine the proton MR (1H-MR) spectra of normal adult testes and variations with age.

METHODS

Forty-one MR spectra of normal testes, including 16 testes from men aged 20-39 years (group I) and 25 testes from men aged 40-69 years (group II), were analyzed. A single-voxel point-resolved spectroscopy sequence (PRESS), with TR/TE: 2000/25 ms was used. The volume of interest was placed to include the majority of normal testicular parenchyma. Association between normalized metabolite concentrations, defined as ratios of the calculated metabolite concentrations relative to creatine concentration, and age was assessed.

RESULTS

Quantified metabolites of the spectra were choline (Cho), creatine (Cr), myo-inositol (mI), scyllo-inositol, taurine, lactate, GLx compound, glucose, lipids, and macromolecules resonating at 0.9 ppm (LM09), around 20 ppm (LM20), and at 13 ppm (LM13). Most prominent peaks were Cho, Cr, mI, and lipids. A weak negative correlation between mI and age (P = 0.015) was observed. Higher normalized concentrations of Cho (P = 0.03), mI (P = 0.08), and LM13 (P = 0.05) were found in group I than in group II.

CONCLUSIONS

1H-MR spectra of a normal adult testis showed several metabolite peaks. A decrease of levels of Cho, mI, and LM13 was observed with advancing age.

KEY POINTS

• Single-voxel PRESS MRS of a normal testis is feasible. • 1H-MR spectra of a normal testis showed several metabolite peaks. • Most prominent peaks were Cho, Cr, mI, and lipids. • A decrease of Cho, mI, and LM13 was seen with advancing age.

Testicular calculus: A rare case

Background:

Testicular calculus is an extremely rare case with unknown etiology and pathogenesis. To our knowledge, here we report the third case of testicular calculus. A 31-year-old man was admitted to our clinic with painful solid mass in left testis. After diagnostic work-up for a possible testicular tumour, he underwent inguinal orchiectomy and histopathologic examination showed a testicular calculus.

Case hypothesis:

Solid testicular lesions in young adults generally correspond to testicular cancer. Differential diagnosis should be done carefully.

Future implications:

In young adults with painful and solid testicular mass with hyperechogenic appearance on scrotal ultrasonography, testicular calculus must be kept in mind in differential diagnosis. Further reports on this topic may let us do more clear recommendations about the etiology and treatment of this rare disease.