Ultrasound contrast-enhanced diagnosis of testicular Leydig cell tumor: A case report and literature review.

Leydig cell tumor (LCT) is a rare testicular tumor. We report a case of an elderly male patient who discovered a left testicular mass during a regular health examination four years ago. The patient did not experience any significant discomfort and opted for regular follow-up visits. During the most recent visit, we performed routine ultrasound and contrast-enhanced ultrasound (CEUS) examinations. By observing the lesion's location, echogenicity, margins, vascular distribution, as well as the rapid enhancement and slow washout characteristics on contrast-enhanced ultrasound, we arrived at a diagnosis of LCT. Subsequently, the patient underwent left inguinal orchiectomy. Postoperative pathology and immunohistochemistry confirmed the diagnosis of LCT. Additionally, we conducted a comprehensive review of LCT-related literature from PubMed and SCOPUS, summarizing the clinical features, follow-up duration, prognosis, and ultrasound characteristics associated with LCT.

Leydig cell tumor of the testis with characteristic contrast patterns of tumor and non-tumorous testicular parenchyma on MRI: a case report.

PURPOSE: Testicular Leydig cell tumor (LCT) is a rare subtype of testicular neoplasms that occurs in the interstitial tissue of testes, accounting for 1-3% of total testicular masses removed annually. We report a case of 70-year-old man diagnosed as testicular LCT. This report demonstrates a testicular LCT with intratumoral and non-tumorous testicular parenchymal enhancement in the affected testis, which should be considered characteristic findings of LCT. METHODS: Ultrasonography showed a hypoechoic mass. On magnetic resonance imaging, the tumor showed low signal intensity comparable to the surrounding testicular tissue on T1-weighted images (T1WI) and low signal intensity on T2-weighted images (T2WI). On gadolinium contrast-enhanced T1WI (CE-T1WI), the tumor showed a rapid and marked wash-in and subsequent prolonged washout. The spared, non-tumorous testicular parenchyma showed slow and progressive enhancement in the early phase, which was as strong as or stronger than that of the mass in the delayed phase. The patient underwent right orchiectomy. RESULTS: Pathologically, the tumor was diagnosed as a testicular Leydig cell tumor (LCT). Leydig cell proliferation was observed with well-developed microvessels, atrophy of the seminiferous tubules, and stromal edema in the non-tumorous testicular parenchyma. Leydig cells in the non-tumorous parenchyma were positive for estrogen receptors. CONCLUSION: Since the contrast findings in the non-tumorous testicular parenchymal region on CE-T1WI likely match the histopathological features of LCT, our case suggests that the presence of non-tumorous testicular parenchymal enhancement on imaging might indicate a diagnosis of LCT.

Multiparametric ultrasound for the diagnosis of Leydig cell tumours in non-palpable testicular lesions.

BACKGROUND: The widespread use of ultrasonography has led to an increased number of incidentally detected small non-palpable lesions, with Leydig cell tumours representing the majority of them. OBJECTIVES: The ultrasonography, real-time elastography and contrast-enhanced ultrasonography features of a large series of non-palpable testicular lesions were evaluated, focusing on the differences between Leydig cell tumours and other testicular masses. MATERIALS AND METHODS: Of the 4679 testicular ultrasonography examinations performed at the Authors' Institution between January 2009 and December 2018, 78 patients (1.7%) were incidentally diagnosed with at least one non-palpable lesion and were enrolled. Thirteen patients (16.6%) declined surgery and were thus excluded. The remaining 65 underwent surgical resection with frozen section analysis. The conventional ultrasonography, colour Doppler, real-time elastography and contrast-enhanced ultrasonography were performed by a radiologist having more than 10 years of experience. Demographic and clinical data were collected. RESULTS: Leydig cell tumours were detected in 32 patients, being the most frequent benign tumours (49.2%); of the non-Leydig cell tumours, 25 patients had malignant tumours, five non-neoplastic lesions and three other benign tumours. The Leydig cell tumour group had mostly infertility problems whereas the non-Leydig cell tumour group frequently experienced pain (p < 0.001). Leydig cell tumours were all hypoechoic (32/32, 100%; p = 0.002), more frequently presented with well-defined margins compared to non-Leydig cell tumours (30/32, 93.8% vs. 19/33, 57.6%; p = 0.001) and tended to be smaller than non-Leydig cell tumours (5.3 mm [standard deviation 2.7 mm] vs. 10.6 mm [standard deviation 3.8 mm], respectively; p < 0.001). The vascular pattern characterised by the rapid wash-in followed by the delayed wash-out observed during contrast-enhanced ultrasonography was significantly associated with the Leydig cell tumour histological diagnosis, even at multivariate analysis (odds ratio 480.5, p < 0.001), and yielded a high diagnostic accuracy (area under the receiver operating characteristic curve 0.954, 95% confidence interval 0.903-1). DISCUSSION: Contrast-enhanced ultrasonography demonstrated high diagnostic accuracy in identifying benign testicular lesions, such as Leydig cell tumours; they are the most common non-palpable tumours detected in infertile men and may benefit from enucleation.

Precocious puberty related to Leydig cell testicular tumor: the diagnostic imaging keys.

BACKGROUND: We report the challenging case of a 6-year-old boy with precocious puberty related to histologically proven Leydig cell tumor. CASE PRESENTATION: Multiparametric ultrasound and magnetic resonance imaging (MRI) was performed. Interesting findings were scarcely or never reported in children and differed from adults Leydig cell tumors s such as the hyperechogenic halo surrounding the lesion and the dominant central vascularization using ultrasensitive Doppler. MRI revealed an enlarged testicle with strong enhancement of a tumor, a tumor apparent diffusion coefficient (ADC) of 600 × 10-3 mm2/s and a lower ADC value of the non-tumor parenchyma compared to the contralateral testis (ADC = 800 × 10-3 mm2/s vs 1100 × 10-3 mm2/s), attributed to the spermatogenesis induced by hormonal impregnation. CONCLUSION: We illustrate multiparametric US and MRI findings of a pediatric Leydig cell tumor, including the imaging changes attributed to local hormone secretion, which may be helpful in similar cases.

Ultrasound examination assisted clinical diagnosis of Leydig cell tumor of ovary: An extremely rare case report.

INTRODUCTION: Leydig cell tumor (LCT) is a sex cord-stromal tumor, which is a clinically rare ovarian tumor. It is characterized by endocrine hormonal changes and usually occurs in postmenopausal women. PATIENT CONCERNS: We report the clinical case of a 38-year-old female of childbearing age with LCT of the right ovary who presented with significantly decreased menstrual flow and elevated androgen levels, with persistent hypoechoic areas in the ovary as demonstrated by transvaginal ultrasound. DIAGNOSIS: The transvaginal ultrasound suggested the presence of a hypoechoic area in the right ovary with elevated androgens, interstitial tumor of the ovarian sex cord may be considered. INTERVENTIONS: The patient underwent laparoscopic right adnexectomy. OUTCOMES: Postoperative pathology confirmed the morphology and immunohistochemistry of the right adnexa consistent with LCT, and no areas of malignant transformation were found on multiple sections of the surgical specimen. The patient had normal androgen levels at postoperative day 2, day 45 and month 3. There was no sign of recurrence. CONCLUSION: This case suggests that when women of childbearing age have abruptly decreased menstrual flow with increased testosterone, clinicians should pay attention to intra-ovarian occupying lesions and consider the possibility of LCT. In such cases, ultrasound examination can determine the presence, location, shape and size of occupying ovarian lesions and play an important role in the diagnosis of condition.

Role of contrast-enhanced ultrasound with Sonazoid in management of small testicular Leydig cell tumours: A case report with literature review.

Small testicular solid lesions are discovered accidentally due to the extensive use of ultrasound in urology and andrology. Early differentiation between benign and malignant testicular neoplasms is crucial for the determination of treatment options, especially for sub-centimetre lesions. We report a case of a male patient with an incidental discovery of a small testicular lesion on ultrasonography with the chief complaint of left testicular discomfort. The blood-flow distribution and microbubble dynamics in the lesion were evaluated through contrast-enhanced ultrasound using Sonazoid intravenous bolus injection, the rapid and intense enhancement pattern tended to be testicular Leydig cell tumour. Through testicular-sparing surgery, the lesion was excised, and benign testicular Leydig cell tumour was confirmed by post-operative pathology and immunohistochemical pathology. No sign of recurrence or metastasis was detected during follow-up.

Renal interstitial cell tumor in a dog: clinicopathologic, imaging, and histologic features.

Renal interstitial cell tumors are benign tumors of renomedullary origin; however, malignant features have not been reported in dogs, to our knowledge. A 17-y-old spayed female Maltese dog was presented to a local animal hospital with a mass in the right abdomen. Clinicopathologic findings prior to surgery revealed renal insufficiency and anemia. Imaging revealed that the right kidney was enlarged by an amorphous mass with opaque areas, indicative of mineralization. Upon histologic examination, the mass was comprised of malignant mesenchymal cells that produced mucinous matrix. The tumor cells were positive for vimentin and COX-2, but negative for pancytokeratin; the matrix stained positively with alcian blue. Therefore, the mass was diagnosed as a renal interstitial cell tumor, with malignant features. COX-2 may be useful in the diagnosis of canine renal interstitial cell tumors, similar to its diagnostic role in humans.

Testis-sparing Surgery for Pediatric Leydig Cell Tumors: Evidence of Favorable Outcomes Irrespective of Surgical Margins.

OBJECTIVE: To review our single institution experience, exploring the role of testis-sparing surgical resection in a cohort of children with Testicular Leydig cell tumors (LCTs). MATERIALS AND METHODS: We reviewed all consecutive children presenting with testicular tumors between 2003 and 2017 (n = 66), excluding patients with alternative pathologies (n = 57). Subsequently data were collected on age at surgery, laterality, type of surgery, operative time, presenting symptoms, serum markers, imaging findings, frozen section, final pathology, and follow-up. RESULTS: During the study period, a total of 9 (9/66; 14%) children were treated for LCT of the testis. Age at surgery was 8.4 ± 1.7 years and the majority (7/9; 77%) had unilateral disease. Most presented with a testicular mass, and 3 (33%) complained of testicular pain. None of the patients had elevated tumor markers. The primary method of management was ultrasound-guided testis-sparing surgery, with an operative time of 98.5 ± 58.7 minutes. Mean tumor size was 15 ± 10.8 mm (range 5-40 mm). In 2 of 6 patients with positive margins radical orchidectomy was performed without residual disease encountered. At a mean follow-up of 31.8 ± 26.3 months (range 2-87) none of the patients demonstrated disease recurrence. CONCLUSION: Our data suggest that LCT in children is associated with a good prognosis, and that TSS is a reasonable surgical approach without detrimental perioperative morbidity or negative long-term outcomes. Moreover, positive margins should not prompt a reflex decision for completion of orchidectomy.

Postmenopausal androgen-secreting ovarian tumors: challenging differential diagnosis in two cases.

Postmenopausal hyperandrogenism constitutes a very rare condition of tumoral or non-tumoral origin primarily residing either in the ovary or in the adrenal glands. We present herein two cases with this condition; one with abnormal postmenopausal genital bleeding and mild increase in facial hair, and the second with slow-developing hirsutism and virilization. Both cases shared a notorious increase in libido. The laboratory tests showed high levels of testosterone (>100 ng/ml). A normal value of dehydroepiandrosterone sulfate and a normal cortisol level at 9 am after 1 mg of dexamethasone administered at midnight (Nugent test) made an adrenal etiology very unlikely. On the other hand, a high level of inhibine B oriented to an ovarian source. Transvaginal sonography failed to demonstrate an ovarian tumor, but an abdominal and pelvic computed tomography scan or magnetic resonance imaging detected an ovarian tumor and normal adrenal glands. A laparoscopic oophorectomy was performed, and the histological study demonstrated a steroidal cell tumor in the first case and a Leydig cell tumor in the second.

[Ultrasound characteristics of testicular Leydig cell tumors , , , 1.]

OBJECTIVE: To explore the color Doppler ultrasonic characteristics of testicular Leydig cell tumors (LCT) and improve the clinical diagnosis of the disease. METHODS: We retrospectively analyzed 4 cases of testicular LCT diagnosed and treated in our hospital and summarized the experience in the ultrasonic diagnosis of LCT with a review of the relevant literature. RESULTS: All the 4 testicular LCTs were solitary and quasi-round, 1 in the left and 3 in the right. The smallest mass was 1.8 × 1.5 cm and the largest 3.1 × 2.5 cm, and 2 were complicated by hydrocele of tunica vaginalis. The margins of tumors were distinct in 2 cases and indistinct in 1, and changed from distinct to indistinct in another during the follow-up. Hypoechoes were revealed in all the 4 cases in ultrasonography, 2 with abundant internal blood flow, 1 with abundant peripheral blood flow, and the other with abundant internal blood flow changed from circular blood flow surrounding the mass. CONCLUSIONS: A typical sporadic LCT was ultrasonically manifested as an isolated hypoechoic infracentimetric mass with a clear demarcation from the adjacent pulp. It exhibited intrinsic hypervascularization associated with a typical peripheral rim pattern. Larger lesions more often presented a lobulated shape and intense hypervascularization. Although these ultrasonic characteristics do not reveal the nature of LCT with certainty, they can help the surgeon with the decision on testis-sparing surgery or perhaps even on the active monitoring for the smallest lesions in a population with impaired fertility.

Diagnostic pitfalls in ovarian androgen-secreting (Leydig cell) tumours: case series.

Leydig cell tumours of the ovary are rare and represent a diagnostic challenge not only due to their sporadic incidence but also due to the seemingly normal imaging. We present three cases of pre- and postmenopausal women who were presented with severe clinical signs of hyperandogenism where modern imaging modalities (including computed tomography (CT), magnetic resonance imaging (MRI) and positron-emission tomography combined with computed tomography (PET-CT)) failed to identify the tumour. Two patients underwent non-expert ultrasound, CT and MRI examination with uniform conclusion that ovaries are of normal appearance. One of the two patients even had a PET-CT performed, which was inconclusive. Our case reports show the importance of examination by specialists with established skills in gynaecologic ultrasonography in the diagnosis of the Leydig cell tumours. The most useful diagnostic tool seems to be the combination of age (postmenopause), symptoms (onset of hirsutism and virilisation), high total testosterone plasma values and expert sonography. On ultrasound, these tumours are unilateral, usually small, solid intraovarian nodules of a slightly increased echogenicity in contrast to the surrounding ovarian tissue, delineated by abundant perfusion with an enhanced vascularity. The appropriate setting of the sensitive colour Doppler is crucial for the detection of intraovarian Leydig cell tumour. Impact statement What is already known on this subject? A diagnosis of Leydig cell tumours is based on ultrasound performed by a trained examiner or by MRI. CT or PET/CT are not among the primary methods of choice. According to the results of imaging investigations surgical treatment is planned. Because these tumours are usually benign and have a good prognosis the unilateral salpingo-oophorectomy is a standard procedure. What do the results of this study add? Our case series show how difficult it can be to establish the diagnosis of Leydig cell tumours by imaging, including transvaginal ultrasound, the most frequently recommended diagnostic tool. We demonstrate in three cases how easily a small hyperechogenic tumour can be overseen or interchanged for a different gynaecological pathology if transvaginal scan is not performed by an experienced examiner trained in sonographic features of gynaecologic neoplasms. What are the implications of these findings for clinical practice and/or further research? This case series demonstrate how important it is to see the patient in the whole complexity with their medical history, proper clinical symptoms evaluation, laboratory test and not to rely solely just on sophisticated high-end investigations, such as the PET-CT, a CT and an MRI. It also emphasises the importance of specialists with established skills in gynaecologic ultrasonography. Further effort should be made to define the resources for the appropriate training of such sonographers.

An ovarian Leydig cell tumor of ultrasound negative in a postmenopausal woman with hirsutism and hyperandrogenism: A case report.

RATIONALE: The incidence of severe hyperandrogenism associated with masculinity in women is very low. While rare and difficult to diagnose, androgen secreting tumors should be suspected in women with hyperandrogenism and hirsutism, especially in the postmenopausal population. Herein we present one case of ovarian Leydig cell tumor (LCT) with markedly elevated serum testosterone levels and frank hirsutism. PATIENT CONCERNS: A 60-year-old woman, presented with increased hair growth and androgenic alopecia and the hormonal laboratory examination showed that she had elevated serum testosterone level and normal dehydroepiandrosterone sulfate (DHEAS), androstenedione, 17- hydroxyprogesterone, cortisol and thyroid stimulating hormone (TSH). DIAGNOSES: The diagnosis of possible testosterone secreting tumor was performed when pelvic computed tomography (CT) and magnetic resonance image (MRI) showed a right adnexal mass of 15mm×16mm indicative of sex cord- stromal tumors. INTERVENTIONS: The patient received laparoscopic total abdominal hysterectomy and bilateral salpingo-oophorectomy. OUTCOMES: After operation, testosterone got back to the normal level and clinical symptoms subsided. LESSONS: It is common that postmenopausal androgen excess is a state of relative or absolute androgen excess originating from the adrenal gland and/or ovaries. In either case, doctors need to assess such patients and exclude relatively rare potential causes of tumors. Any woman who has hirsutism or frank evidence of markedly increased testosterone should exclude this kind of possibility of androgen producing tumors. It is possible to determine the origin of androgen hypersecretion with the severity of symptoms, the extent of androgen excess, and the relevant imaging studies. Since LCT are rare ovarian sex-cord stromal tumors, it can be beneficial for diagnosis with careful research of patient history of the defeminization followed by virilization, and a CT and MRI image.

Testicular Estrogen-Secreting Leydig Cell Tumor in 18F-FDG PET/CT: An Incidental Detection in a Patient Treated by Chemotherapy for Hodgkin Lymphoma.

We present images of a 50-year-old man who referred for treatment of a classic Hodgkin lymphoma. While F-FDG PET/CT demonstrated a complete metabolic remission after chemotherapy, an increased F-FDG uptake of a right testicular lesion in F-FDG PET/CT and an unexplained bilateral gynecomastia were observed. A benign Leydig cell tumor was histopathologically proved after a right radical orchiectomy. The serum estradiol level was abnormally elevated reflecting the estrogen-secreting profile. This report highlights that a focal F-FDG uptake in the testicular region with unexplained gynecomastia should suggest the diagnosis of an estrogen-secreting Leydig cell tumor on F-FDG PET/CT.

Leydig cell hyperplasia in children: Case series and review.

INTRODUCTION: Leydig cell hyperplasia (LCH) and Leydig cell tumours (LCTs) in children are rare, typically presenting with precocious puberty. Previously, orchidectomy was the routine management; however, more recently, testis-sparing surgery has been performed with good results. We present a series of unusual presentations of LCH, raising new management questions, and a review of the literature regarding LCH and LCT in children. STUDY DESIGN: We performed a literature search using Ovid Medline, PubMed, and Google Scholar, producing 456 articles. We reviewed all case reports and series containing paediatric patients, and relevant review articles. RESULTS: We report three cases of LCH, two of which were incidental findings. All three cases underwent testis-sparing surgery. In the literature there were seven cases of LCH and 101 cases of LCT in prepubertal children. The most common presentation was with precocious puberty. Three cases of LCH and more than two-thirds of LCTs were managed with orchidectomy and overall only 11% of the cases underwent testes-sparing surgery (24% did not specify operative management). There were no reports of recurrence or malignancy. DISCUSSION: Our case series presents three new clinical presentations of LCH that have not previously been reported in the literature: one of incomplete precocious puberty and two with incidental findings on ultrasound in asymptomatic children. Historically, children with the classic presentation of precocious puberty and a testicular lesion have been managed with orchidectomy. Nowadays, many clinicians advocate testes-sparing surgery given there have been no cases of malignancy. In children with no clinical or biochemical signs of precocious puberty, lesions identified on ultrasound can be safely monitored for a period of time. However, if the lesion does not regress, excisional biopsy is recommended to establish the diagnosis, ideally before the onset of puberty. CONCLUSION: Leydig cell hyperplasia and tumours in pre-pubertal children are benign. Testes-sparing surgery with regular follow-up appears to be safe management.

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.

CEUS Time Intensity Curves in the Differentiation Between Leydig Cell Carcinoma and Seminoma: A Multicenter Study.

PURPOSE: Ultrasound (US) is the main imaging technique in the assessment of testicular masses, as it has proved to be highly accurate in the visualization of these pathologies. Identification of a Leydig cell tumor is essential since the lesion is benign in 90% of cases. The aim of this multicenter study is to assess the effectiveness of contrast-enhanced ultrasound (CEUS) in differentiating Leydig cell tumors from seminoma using qualitative and quantitative features. MATERIALS AND METHODS: From February 2011 to December 2013, 31 patients (mean age: 34 years; range: 25 - 52) were recruited for this prospective study. Three of them were monorchid. Therefore, a total of 59 testicles were assessed. All patients underwent grayscale US, color Doppler ultrasound (CDUS), CEUS and orchiectomy. The paired one-tailed Student's t-test was carried out to differentiate between Leydig cell tumors and seminomas. RESULTS: 31 lesions suspicious for malignancy were hypoechoic on grayscale US while they did not show a typical pattern on CDUS. CEUS qualitative analysis, based on contrast enhancement pattern, during the arterial and venous phases, did not allow discrimination of Leydig cell tumors from seminoma. Quantitative analysis of time-intensity curves (TICs) demonstrated that only three parameters presented statistical significance, i. e. wash-in rate (WiR) p = 0.014, peak enhancement (PE) p = 0.001 and time to peak (TTP) p = 0.003. CONCLUSION: The vascular bed of a Leydig cell tumor is wider and the blood flow velocity is higher than that of a seminoma due to more regular neovascularization. In contrast, a seminoma presents large areas of necrosis due to irregular neovascularization. This explains the different PE and WiR values. Further studies involving larger patient populations are mandatory to confirm these encouraging preliminary results.

The value of testicular ultrasound in the prediction of the type and size of testicular tumors.

OBJECTIVES: Ultrasound (US) is often used for the work-up of testicular pathology. The findings may implicate on its management. However, there is only scant data on the correlation between US findings and testicular tumor type and size. Herein, we report on a multicenter study, analyzing these correlations. METHODS: The study included patients who underwent orchiectomy between 2000 and 2010. Their charts were reviewed for US echogeneity, lesion size, pathological dimensions, histology, and the presence of calcifications, fibrosis, necrosis and/or intraepithelial neoplasia. The incidence of these parameters in benign versus malignant lesions and seminomatous germ cell tumors (SGCT) versus nonseminomatous germ cell tumors (NSGCT) was statistically compared. RESULTS: Eighty five patients fulfilled the inclusion criteria, 71 malignant (43 SGCT, 28 NSGCT) and 14 benign. Sonographic lesions were at least 20% smaller than the pathologically determined dimensions in 21 (25%) patients. The ability of US in estimating the size of malignant tumors was 71%, compared to 100% of benign tumors (p=0.03), with no significant difference between SGCT and NSGCT. Necrosis was more frequent in malignant tumors (p=0.03); hypoechogeneity and fibrosis were more frequent in SGCT than in NSGCT (p=0.002 and 0.04 respectively). CONCLUSIONS: Testis US of malignant lesions underestimates the size in 25% of the cases, a fact that may impact on the decision of testicular sparing surgery. The ultrasonic lesions were eventually proven to be benign in 16% of the cases. Therefore it is advised to apply frozen sections in borderline cases. Hypoechogeneity is more frequent in SGCT than NSGCT.