Comparison of computed versus acquired readout-segmented diffusion-weighted imaging in visualizing scrotal or testicular lesions.

PURPOSE: Combining computed diffusion-weighted imaging (DWI) with readout-segmented echo-planar-imaging may shorten acquisition time and improve imaging quality. This study aimed to compare computed vs. acquired DWI qualitatively and quantitatively in visualizing scrotal or testicular lesions. MATERIALS AND METHODS: We retrospectively enrolled 57 consecutive men who underwent scrotal MRI. Four computed DWI sets (cDWI800, cDWI1000, cDWI1200, and cDWI1400) were generated from acquired DWI with two lower b-values (150 and 600 s/mm2). Acquired DWI (DWI800 and DWI1000) and computed DWI were compared through qualitative (susceptibility artifact, signal loss artifact, anatomic clarity, and lesion conspicuity) and quantitative assessment (signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and lesion-to-testicular parenchyma contrast ratio (CR)). RESULTS: Computed DWI was prone to signal loss artifact and slightly lower assessment scores in terms of anatomic clarity and lesion conspicuity, comparing with acquired DWI. The SNR of computed and acquired DWI decreased with increasing b value. Under the same b-values (800 and 1,000 s/mm2), there was no difference in the median SNR and CR between computed and acquired DWI. The median CR of cDWI1400 was significantly higher than that of the other DWI sets excepting cDWI1200 (P=1.000). The median CNR tended to be lower for computed vs. acquired DWI, while no significant difference (P=0.233). CONCLUSIONS: Computed and acquired DWI were nearly equivalent in both qualitative and quantitative evaluations at the b values of 800 and 1,000 s/mm2. Computed DWI could enhance the contrast of scrotal or testicular lesions.

Extratesticular masses focusing on MRI findings.

Scrotal masses, whether cystic or solid lesions, are routinely evaluated using ultrasonography. Magnetic resonance imaging (MRI) may be used for further investigation in cases with atypical findings, difficult diagnoses, large masses, and/or unclear relationships with the surrounding tissues. Scrotal solid masses are divided into intra- and extra-testicular masses. A staggering 90% of the intratesticular masses are malignant, whereas 75% of extratesticular masses are benign. Extratesticular masses are less common than intratesticular masses; however, some extratesticular masses present characteristic MRI findings. Familiarity with these specific MRI features of extratesticular masses is beneficial to radiologists, as appropriate diagnoses can help avoid unnecessary invasive treatments such as orchiectomy. In this review, we describe fibrous pseudotumors, polyorchidism, adenomatoid tumors, and scrotal leiomyoma as benign paratesticular masses, focusing on their characteristic imaging features on MRI. Although these tumors are extremely rare, their MRI findings are distinctive, and accurate diagnoses can prevent unnecessary orchiectomy. In addition, to demonstrate the pitfalls of diagnosing extratesticular masses, we present a case of seminoma misidentified as extratesticular masses due to large extensions outside the testis. Spermatic cord sarcoma, including rhabdomyosarcoma, leiomyosarcoma, and liposarcoma, and metastasis to the spermatic cord are described as malignant extratesticular masses. This review focused on extratesticular masses and elaborates the imaging findings that can aid in the accurate diagnosis using MRI.

Computed tomographic characteristics of testicular teratoma in a cat.

A 5-year-old intact male mixed-breed cat weighing 4.5 kg was referred to our hospital with a left testicular mass. CT revealed mild heterogeneous contrast enhancement and calcification in the testicular mass. A well-defined, contrast-enhancing, multiloculated mass with fluid-filled areas was extended from the testicular mass in the scrotum to the caudal aspect of the left kidney. The abdominal mass extended to the right crus of the diaphragm, and the gastrointestinal tract was compressed dorsally. Histopathology was consistent with teratoma. Characteristic CT findings in a feline testicular teratoma may include calcification and cystic areas.

Diagnostic and therapeutic challenges with germ cell tumours associated with transverse testicular ectopia and persistent Müllerian duct syndrome.

Transverse testicular ectopia (TTE) is an infrequent ectopic testis where both testes descend via the same inguinal canal, located in the same hemiscrotum, and augments the risk of developing testicular tumours. Type II TTE is accompanied by persistent Müllerian duct syndrome, where the Müllerian structures persist for various reasons. Here, we present a case of an adult in his early 30s, who presented with a right testicular swelling and was diagnosed as type II TTE and testicular mixed germ cell tumour after surgery. We could find only 13 similar cases of TTE and testicular tumours in the literature. Our case highlights the importance of clinical acumen with detailed history, meticulous clinical examination, radiological investigations and a detailed pathological examination while dealing with such sporadic presentations.

Assessment of quantitative microflow Vascular Index in testicular cancer.

PURPOSE: Ultrasound (US) is the primary imaging modality when a testicular tumor is suspected. Superb microvascular imaging (SMI) is a novel, highly sensitive Doppler technique that allows quantification of flow signals by determination of the Vascular Index (VI). The aim of the present study is to investigate the diagnostic significance of the SMI-derived VI in normal testicular tissue and testicular cancer. METHODS: This retrospective analysis included patients who underwent testicular US in our department from 2018 to 2022. Inclusion criteria were: i) sufficient image quality of the stored images, ii) US with standardized SMI-default setting (colour gain of 44 ± 5), iii) patient age ≥ 18 years, and iv) normal testicular findings or testicular tumor with histopathological workup. US examinations were performed as part of clinical routine using a high-end ultrasound system (Aplio i800/i900, Canon Medical Systems Corporation, Tochigi, Japan). Statistical analysis included Chi-square test and Mann-Whitney U tests and receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 62 patients (31 each with normal findings and testicular tumors) were included. The VI differed statistically significantly (p < 0.001) between normal testis (median 2.5 %) and testicular tumors (median 17.4 %). Like vascular patterns (p < 0.001), the VI (p = 0.030) was shown to distinguish seminomas (median 14.8 %), non-seminomas (median 17.6 %) and lymphomas (median 34.5 %). CONCLUSIONS: In conclusion, our study has shown the VI to be a quantitative tool that can add information for differentiating testicular tumor entities. While further confirmation in larger study populations is desirable, our results suggest that the VI may be a useful quantitative parameter.

[Testicular tumor in a 9-year-old boy]. / Hodentumor bei 9-jährigem Kind.

A 9-year-old boy presented to the emergency department after noticing a painless mass on the right testicle during self-examination in the shower. On physical examination, both testes were mobile and painless, with the right testis twice as big as the left and exhibiting palpable resistance. Sonographic examination revealed a uniformly demarcated mass with a ventral protrusion on the right testis. Tumor markers and blood tests were normal. The testis was exposed inguinally and the tumor was enucleated, which revealed a dermoid cyst. The testicle could thus be preserved. Final histology confirmed complete excision of the benign dermoid cyst (mature teratoma). As testicular tumors in prepubertal boys are rare and usually benign, an organ-preserving procedure with perioperative biopsy should be aimed for. Due to the rarity of studies on recurrence after organ-preserving testicular surgery, we recommended regular ultrasound examinations during the first year after surgery, followed by annual examinations for a period of 5 years.

A Machine Learning Model to Predict the Histology of Retroperitoneal Lymph Node Dissection Specimens.

BACKGROUND/AIM: While post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) benefits patients with teratoma or viable germ cell tumors (GCT), it becomes overtreatment if necrosis is detected in PC-RPLND specimens. Serum microRNA-371a-3p correctly predicts residual viable GCT with 100% sensitivity; however, prediction of residual teratoma in PC-RPLND specimens using current modalities remains difficult. Therefore, we developed a machine learning model using CT imaging and clinical variables to predict the presence of residual teratoma in PC-RPLND specimens. PATIENTS AND METHODS: This study included 58 patients who underwent PC-RPLND between 2005 and 2019 at the University of Tsukuba Hospital. On CT imaging, 155 lymph nodes were identified as regions of interest (ROIs). The ResNet50 algorithm and/or Support Vector Machine (SVM) classification were applied and a nested, 3-fold cross-validation protocol was used to determine classifier accuracy. RESULTS: PC-RPLND specimen analysis revealed 35 patients with necrosis and 23 patients with residual teratoma, while histology of 155 total ROIs showed necrosis in 84 ROIs and teratoma in 71 ROIs. The ResNet50 algorithm, using CT imaging, achieved a diagnostic accuracy of 80.0%, corresponding to a sensitivity of 67.3%, a specificity of 90.5%, and an AUC of 0.84, whereas SVM classification using clinical variables achieved a diagnostic accuracy of 74.8%, corresponding to a sensitivity of 59.0%, a specificity of 88.1%, and an AUC of 0.84. CONCLUSION: Our machine learning models reliably distinguish between necrosis and residual teratoma in clinical PC-RPLND specimens.

[Testicular involvement in pediatric lymphoid tumors: a review of the literature and a series of clinical observation].

Lymphoid tumors with testicular involvement in childhood are rare and heterogeneous. The disease may manifest with uni- or bilateral scrotal enlargement. Comprehensive examination includes evaluation of all lymph nodes involvement, as well as ultrasound examination, magnetic resonance imaging and positron emission tomography. A diagnosis is made on basis of morphological and immunohistochemical verification. Determination of lymphoid tumor variant and stage, is recommended to perform chemotherapy according to prognostic risk group, and, in some cases, transplantation of hematopoietic stem cells is required as consolidation therapy. We present three rare clinical cases of follicular lymphoma with testicular involvement, T-lymphoblasti progenitor cell lymphoma, and B-lineage acute lymphoblastic leukemia (ALL) relapse. Different schemes of chemotherapy, combined with orchiectomy (in 2 of 3 cases) resulted in prolonged complete remission. In the first case, due to treatment-refractory B-lineage ALL, the disease was incurable. Our data on clinical, morphological, immunohistochemical and therapeutic features of lymphoid tumors with testicular involvement make it necessary to form multidisciplinary teams, including pediatric urologists, hematologic oncologists and surgeons for timely diagnosis and successful treatment.

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.

Differentiation of testicular seminomas from nonseminomas based on multiphase CT radiomics combined with machine learning: A multicenter study.

BACKGROUND: Differentiating seminomas from nonseminomas is crucial for formulating optimal treatment strategies for testicular germ cell tumors (TGCTs). Therefore, our study aimed to develop and validate a clinical-radiomics model for this purpose. METHODS: In this study, 221 patients with TGCTs confirmed by pathology from four hospitals were enrolled and classified into training (n = 126), internal validation (n = 55) and external test (n = 40) cohorts. Radiomics features were extracted from the CT images. After feature selection, we constructed a clinical model, radiomics models and clinical-radiomics model with different machine learning algorithms. The top-performing model was chosen utilizing receiver operating characteristic (ROC) curve analysis. Decision curve analysis (DCA) was also conducted to assess its practical utility. RESULTS: Compared with those of the clinical and radiomics models, the clinical-radiomics model demonstrated the highest discriminatory ability, with AUCs of 0.918 (95 % CI: 0.870 - 0.966), 0.909 (95 % CI: 0.829 - 0.988) and 0.839 (95 % CI: 0.709 - 0.968) in the training, validation and test cohorts, respectively. Moreover, DCA confirmed that the combined model had a greater net benefit in predicting seminomas and nonseminomas. CONCLUSION: The clinical-radiomics model serves as a potential tool for noninvasive differentiation between testicular seminomas and nonseminomas, offering valuable guidance for clinical treatment.

Split-bolus single-phase versus single-bolus split-phase CT acquisition protocols for staging in patients with testicular cancer: A retrospective study.

INTRODUCTION: Computed tomography (CT) imaging has become indispensable in the management of medical oncology patients. Risks associated with high cumulative effective dose (CED) are relevant in testicular cancer patients. Split-bolus protocols, whereby the contrast medium injection is divided into two, followed by combining the required phase images in a single scan acquisition has been shown to provide images of comparable image quality and less radiation dose compared to single-bolus split-phase CT for various indications. We retrospectively evaluated the performance of split-bolus and single-bolus protocols in patients having follow-up CT imaging for testicular cancer surveillance. METHODS: 45 patients with testicular cancer undergoing surveillance CT imaging of the thorax, abdomen, and pelvis who underwent split-bolus and single-bolus protocols were included. Quantitative image quality analysis was conducted by placing region of interests in pre-defined anatomical sub-structures within the abdominal cavity. The signal-to-noise ratio (SNR) and radiation dose in the form of dose length product (DLP) and effective dose (ED) were recorded. RESULTS: The DLP and ED for the single-bolus, split-phase acquisition was 506 ± 89 mGy cm and 7.59 ± 1.3 mSv, respectively. For the split-bolus, single-phase acquisition, 397 ± 94 mGy∗cm and 5.95 ± 1.4 mSv, respectively (p < 0.000). This represented a 21.5 % reduction in radiation dose exposure. The SNR for liver, muscle and fat for the single-bolus were 7.4, 4.7 and 8, respectively, compared to 5.5, 3.8 and 7.4 in the split-bolus protocol (p < 0.001). CONCLUSION: In a testicular cancer patient cohort undergoing surveillance CT imaging, utilization of a split-bolus single-phase acquisition CT protocol enabled a significant reduction in radiation dose whilst maintaining subjective diagnostic acceptability. IMPLICATIONS FOR PRACTICE: Use of split-bolus, single-phase acquisition has the potential to reduce CED in surveillance of testicular cancer patients.

68 Ga-PSMA Uptake in the Testis : Two Different Patients With Two Different Diagnosis.

ABSTRACT: Although abnormal 68 Ga-PSMA uptake in the prostate and its metastases can be seen in a variety of diseases, it is rare to see in the testis. In these 2 cases, 68 Ga-PSMA PET/CT revealed unilateral 68 Ga-PSMA uptake in the testis of 2 patients. One of these patients was diagnosed with testis metastases from prostate cancer after an orchiectomy. The other patient was diagnosed with an orchitis. 68 Ga-PSMA uptake should be considered as an infection, as well as a malignancy in the initial differential diagnosis.

Initial surveillance in men with marker negative clinical stage IIA non-seminomatous germ cell tumours.

OBJECTIVES: To assess whether extended surveillance with repeated computed tomography (CT) scans for patients with clinical stage IIA (CS IIA; <2 cm abdominal node involvement) and negative markers (Mk-) non-seminomatous germ cell tumours (NSGCTs) can identify those with true CS I. To assess the rate of benign lymph nodes, teratoma, and viable cancer in retroperitoneal lymph node dissection (RPLND) histopathology for patients with CS IIA Mk- NSGCT. PATIENTS AND METHODS: Observational prospective population-based study of patients diagnosed 2008-2019 with CS IIA Mk- NSGCT in the Swedish and Norwegian Testicular Cancer Group (SWENOTECA) registry. Patients were managed with surveillance, with CT scans, and tumour markers every sixth week for a maximum of 18 weeks. Patients with radiological regression were treated as CS I, if progression with chemotherapy, and remaining CS IIA Mk- disease with RPLND. The end-point was the number and percentage of patients down-staged to CS I on surveillance and rate of RPLND histopathology presented as benign, teratoma, or viable cancer. RESULTS: Overall, 126 patients with CS IIA Mk- NSGCT were included but 41 received therapy upfront. After surveillance for a median (range) of 6 (6-18) weeks, 23/85 (27%) patients were in true CS I and four (5%) progressed. Of the remaining 58 patients with lasting CS IIA Mk- NSGCT, 16 received chemotherapy and 42 underwent RPLND. The RPLND histopathology revealed benign lymph nodes in 11 (26%), teratoma in two (6%), and viable cancer in 29 (70%) patients. CONCLUSIONS: Surveillance with repeated CT scans can identify patients in true CS I, thus avoiding overtreatment. The RPLND histopathology in patients with CS IIA Mk- NSGCT had a high rate of cancer and a low rate of teratoma.

Apparent diffusion coefficient histogram in the differentiation of benign and malignant testicular tumors.

Purpose: This retrospective study assessed the value of histogram parameters of the apparent diffusion coefficient (ADC) map (HA) in differentiating between benign and malignant testicular tumors. We compared the diagnostic performance of two different volume-of-interest (VOI) placement methods: VOI 1, the entire tumor; VOI 2, the tumor excluding its cystic, calcified, hemorrhagic, and necrotic portions. Materials and methods: We retrospectively evaluated 45 patients with testicular tumors examined with scrotal contrast-enhanced magnetic resonance imaging. These patients underwent surgery with the pathological result of seven benign and 39 malignant tumors. We calculated the HA parameters, including mean, median, maximum, minimum, kurtosis, skewness, entropy, standard deviation (SD), mean of positive pixels, and uniformity of positive pixels by the two different VOI segmentation methods. We compared these parameters using the chi-square test, Mann-Whitney U test, and area under the receiver operating characteristic curve (AUC) to determine their optimal cut-off, sensitivity (Se), and specificity (Sp). Result: This study included 45 patients with 46 testicular lesions (seven benign and 39 malignant tumors), one of which had bilateral testicular seminoma. With the VOI 1 method, benign lesions had significantly lower maximum ADC (p = 0.002), ADC skewness (p = 0.017), and ADC variance (p = 0.000) than malignant lesions. In contrast, their minimum ADC was significantly higher ADC (p = 0.000). With the VOI 2 method, the benign lesions had significantly higher ADC SD (p = 0.048) and maximum ADC (p = 0.015) than malignant lesions. In contrast, their minimum ADC was significantly lower (p = 0.000). With the VOI 1 method, maximum ADC, ADC variance, and ADC skewness performed well in differentiating benign and malignant testicular lesions with cut-offs (Se, Sp, AUC) of 1846.000 (74.4%, 100%, 0.883), 39198.387 (79.5%, 85.7%, 0.868), and 0.893 (48.7%, 100%, 0.758). Conclusion: The HA parameters showed value in differentiating benign and malignant testicular neoplasms. The entire tumor VOI placement method was preferable to the VOI placement method excluding cystic, calcified, hemorrhagic, and necrotic portions in measuring HA parameters. Using this VOI segmentation, maximum ADC performed best in discriminating benign and malignant testicular lesions, followed by ADC variance and skewness.