Testicular Germ Cell Tumors: Classification, Pathologic Features, Imaging Findings, and Management

Nuclear medicine imaging in non-seminomatous germ cell tumors: lessons learned from the past failures

There is an unmet need for a more accurate molecular imaging radiotracer in the field of non-seminomatous germ cell tumors (NSGCT). The clinical problem is that no single imaging modality is able to differentiate teratoma from necrotic tissue in NSGCTs, which the nuclear medicine techniques are no exception. The exponential growth in the list of potentially promising radiotracers may hold promise in the future for imaging of NSGCTs. Here, we have reviewed the past efforts and potential future advances in this field.

New sights on long non-coding RNAs in glioblastoma: A review of molecular mechanism

Glioma or glioblastoma (GBM) is one of the aggressive and fatal primary cerebral malignancies, with the highest mortality rate among all brain-related tumors. Also, glioma mainly progresses as a more invasive phenotype after primary treatment. Cumulative evidence suggested that dysregulation of noncoding RNAs (ncRNAs) such as long non-coding RNAs (LncRNAs) and microRNAs (miRNAs) are associated with tumor initiation, progression, and drug resistance, through epigenetic modifications, transcriptional, and post-transcriptional processes in the cells. Many scientific investigations have revealed that LncRNAs play important roles in various biological procedures linked with the development and progression of GBM. In recent years, it has been shown that dysregulation of molecular mechanisms in many LncRNAs such as MIR22HG, HULC, AGAP2-AS1, MALAT1, PVT1, TTTY14, HOTAIRM1, PTAR, LPP-AS2, LINC00336, and TINCR are connected with the GBM. Therefore, this scientific review paper focused on the molecular mechanisms of these LncRNAs in the context of GBM.

French AFU Cancer Committee Guidelines - Update 2024-2026: Testicular germ cell cancer

OBJECTIVE

To update the recommendations for the management of germ cell tumours of the testis.

MATERIALS AND METHODS

Comprehensive PubMed review from 2022 on the diagnosis, treatment and follow-up of testicular germ cell tumours (TGT), as well as safety of treatments. The level of evidence of the studies was assessed.

RESULTS

The initial assessment of a patient with a germ cell tumour of the testis is based on a clinical examination, biological evaluation (by measuring the serum markers AFP, total hCG, and LDH) and radiological evaluation (scrotal ultrasound and thoraco-abdomino-pelvic computed tomography [TAP]). Inguinal orchiectomy is the first therapeutic step, as it allows histological diagnosis and defines the local stage and risk factors for progression in stage I nonseminomatous germ cell tumours (NSGCTs). For patients with pure stage I seminoma, the risk of progression is between 15 and 20%, so surveillance is preferred in compliant patients; adjuvant chemotherapy with carboplatin AUC 7 is an option; and the indications for lumbo-aortic radiotherapy are limited. For patients with stage I NSGCT, various options exist, namely, surveillance or a risk-adapted strategy (surveillance or 1 cycle of bleomycin etoposide cisplatin [BEP] depending on the presence or absence of vascular emboli within the tumour). Retroperitoneal lymph node dissection for staging has a very limited role. Treatment of metastatic GCT consists of chemotherapy with BEP in the absence of contraindication to bleomycin, the number of cycles of which is defined according to the prognostic groups of the International Germ Cell Cancer Consortium Group (IGCCCG). Lumbo-aortic radiotherapy is still the standard treatment for stage IIA seminomatous germ cell tumours (SGCTs). At the end of chemotherapy, the size of any residual mass should be assessed via a TAP scan for SNGCTs, with retroperitoneal lymph node dissection recommended for any residual mass greater than 1cm, along with removal of all other metastatic sites. For SGCT, reassessment via 18FDG PET scans is necessary to determine the surgical indication for residual masses>3cm. Surgery remains rare in these situations.

CONCLUSION

Adherence to the recommendations for the management of GCT results in excellent specific survival rates of 99% for patients with stage I disease and over 85% for patients with metastatic disease.

Diffuse peritoneal dissemination of intracranial pure germinoma via ventriculoperitoneal shunt

Germinomas frequently cause hydrocephalus, and ventriculoperitoneal shunts (VPS) have been commonly used for their management. Although VPS can potentially serve as a route for peritoneal dissemination of germinomas, the abdominal imaging characteristics of this rare yet important complication remain unknown. In this article, we report the computed tomography imaging findings of diffuse peritoneal dissemination of intracranial germinoma.

Discriminating Malignant from Benign Testicular Masses Using Multiparametric Magnetic Resonance Imaging-A Prospective Single-Center Study

Objective: The objective of this study was to prospectively assess the extent to which magnetic resonance imaging (MRI) can differentiate malignant from benign lesions of the testis. Materials and Methods: All included patients underwent multiparametric testicular MRI, including diffusion-weighted imaging (DWI) and subtraction dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). Subsequently, all patients underwent a histopathological examination via orchiectomy or testicular biopsy/partial resection. The Kolmogorov-Smirnov test, t-test, Mann-Whitney U test, Fisher's exact test, and logistic regression were applied for statistical analysis. Results: We included 48 male patients (median age 37.5 years [range 18-69]) with testicular tumors. The median tumor size on MRI was 2.0 cm for malignant tumors and 1.1 cm for benign tumors (p < 0.05). A statistically significant difference was observed for the type (type 0-III curve, p < 0.05) and pattern of enhancement (homogeneous, heterogeneous, or rim-like, p < 0.01) between malignant and benign tumors. The minimum apparent diffusion coefficient (ADC) value was 0.9 for benign tumors and 0.7 for malignant tumors (each ×103 mm2/s, p < 0.05), while the mean ADC was 0.05. The mean ADC value was significantly lower for malignant tumors; the mean ADC value was 1.1 for benign tumors and 0.9 for malignant tumors (each ×103 mm2/s, p < 0.05). The sensitivity, specificity, positive predictive value, and negative predictive value of multiparametric MRI for differentiating malignant from benign testicular lesions were 94.3%, 76.9%, 91.7%, and 83.3%, respectively. The surgical procedures performed included orchiectomy (n = 33; 71.7%) and partial testicular resection (n = 11; 23.9%). Histopathology (HP) revealed malignancy in 35 patients (72.9%), including 26 with seminomas and 9 with non-seminomatous germ cell tumors (NSGCTs). The HP was benign in 13 (27.1%) patients, including 5 with Leydig cell tumors. Conclusions: Malignant and benign tumors differ in MRI characteristics in terms of the type and pattern of enhancement and the extent of diffusion restriction, indicating that MRI can be an important imaging modality for the accurate diagnosis of testicular lesions.

Staging and Restaging Pediatric Abdominal and Pelvic Tumors: A Practical Guide

The most common abdominal malignancies diagnosed in the pediatric population include neuroblastoma, Wilms tumor, hepatoblastoma, lymphoma, germ cell tumor, and rhabdomyosarcoma. There are distinctive imaging findings and patterns of spread for each of these tumors that radiologists must know for diagnosis and staging and for monitoring the patient's response to treatment. The multidisciplinary treatment group that includes oncologists, surgeons, and radiation oncologists relies heavily on imaging evaluation to identify the best treatment course and prognostication of imaging findings, such as the image-defined risk factors for neuroblastomas, the PRETreatment EXtent of Disease staging system for hepatoblastoma, and the Ann Arbor staging system for lymphomas. It is imperative for radiologists to be able to correctly indicate the best imaging methods for diagnosis, staging, and restaging of each of these most prevalent tumors to avoid inconclusive or unnecessary examinations. The authors review in a practical manner the most updated key points in diagnosing and staging disease and assessing response to treatment of the most common pediatric abdominal tumors. ©RSNA, 2024 Supplemental material is available for this article.

Component Patterns and Survival Outcomes in Patients with Mixed Malignant Ovarian Germ Cell Tumors: A Retrospective Cohort Study

AIMS

To evaluate the component patterns and risk stratification in patients with mixed malignant ovarian germ cell tumors (mMOGCT).

METHODS

A retrospective study of 70 mMOGCT patients treated in our hospital between 2000 and 2022 was conducted. The recurrence-free survival (RFS), disease-specific survival (DSS), and risk stratification systems based on scoring the identified prognostic factors were assessed.

RESULTS

Yolk sac tumor component was the most common type (80%), followed by dysgerminoma (50%), immature teratoma (40%), embryonic carcinoma (27.1%), and chorionic carcinoma (15.7%). The 5-year RFS and DSS rates were 77.9% and 87.9%, respectively. International federation of gynecology and obstetrics (FIGO) stage III-IV (RR 3.253, P = 0.029) and normalization of tumor marker (TM) ≤ 3 cycles of chemotherapy (RR 6.249, P = 0.017) were risk factors for RFS and DSS, respectively. Significant DSS (RR 8.268, P = 0.006) was also noted between patients who had normalized TM ≤ 4 and ≥5 cycles of chemotherapy. FIGO stages I-II and stages III-IV were scored as 0 and 2, respectively. AFP normalization ≤3, 4, and ≥5 cycles of chemotherapy were scored as 0, 1, and 4, respectively. A total score of 0, 1-2, and ≥3 stratified patients into low-risk (43 patients), intermediate-risk (13 patients), and high-risk groups (14 patients), respectively. Patients in three risk stratifications manifested significant differences in DSS (P = 0.010) but not in RFS (P > 0.05).

CONCLUSION

Distinct different component patterns existed among mMOGCT patients, and predicting survival outcomes in a universal model was challenging.

Testicular Mixed Germ Cell Tumor (TMGCT) Management: Addressing Infection and Tumor Marker Dynamics

We report the case of a 23-year-old male presenting with right testicular swelling, post-coital pain, and fever. Initial MRI and local examination suggested testicular carcinoma. Elevated serum alpha-fetoprotein (AFP) and lactate dehydrogenase (LDH) levels were observed. Biopsy confirmed a mixed germ cell tumor (MGCT). Concurrently, the patient was diagnosed with an infection and treated with antibiotics. Remarkably, following antibiotic therapy, fever resolved, and tumor marker levels significantly decreased. Subsequent orchidectomy confirmed the diagnosis of MGCT. This case underscores the importance of recognizing and treating concurrent infections, which may influence both clinical presentation and tumor marker levels in testicular germ cell tumors.

A comprehensive analysis of the KLRB1 expression and its clinical implication in testicular germ cell tumors: A review

Testicular germ cell tumors (TGCT) are the most common testicular malignancies. KLRB1 is considered to influence the development and progression of a number of cancers. However, it is unclear how the KLRB1 gene functions in TGCT. First, it was determined the expression level of KLRB1 in TGCT using The Cancer Genome Atlas (TCGA) (The Cancer Genome Atlas) dataset and GTEx (Genotype-Tissue Expression) dataset. The clinical significance and biological functions of KLRB1 were explored using the TCGA dataset, and we analyzed the correlation of the KLRB1 gene with tumor immunity and infiltrating immune cells using gene set variation analysis and the TIMER database. We found that the expression level of KLRB1 was upregulated in TGCT malignant tissues with the corresponding normal tissues as controls, and KLRB1 expression correlated with clinicopathologic features of TGCT. Functional enrichment analysis suggested that KLRB1 might be involved in immune response and inflammatory response. KLRB1 was highly positively correlated with natural killer cell activation in immune response and positively correlated with tumor-infiltrating immune cells. This study demonstrated for the first time the role of KLRB1 in TGCT, which may serve as a new biomarker associated with immune infiltration and provide a potential therapeutic target for the treatment of TGCT.

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.

Cytodiagnostic Dilemma in a Lung Mass as the First Presentation of Testicular Mixed Germ Cell Tumor Metastasis

Testicular mixed germ cell tumors (TMGCTs) are rare malignant tumors comprising of two or more types of germ cell tumors. Their onset may be undetectable and the patient may first present with symptoms of metastasis. We hereby report a case of a young male who presented with respiratory discomfort and had no symptoms of primary testicular tumor. CT-guided FNAC lung revealed mainly necrotic, keratinous debris with a focus of chondromyxoid stroma. Differential diagnoses of components of teratoma, squamous cell carcinoma and inclusion cyst was considered. FNAC was reported out for the possible presence of teratoma components. Retrospectively, physical examination and subsequent USG revealed testicular tumor. The case led to a diagnostic dilemma as the patient presented with no prior history suggestive of metastasis from testicular mixed germ cell tumor. The aim of the current case report is to alert the pathologists and clinicians about this uncommon clinical presentation and diagnostic relevance of FNA. It highlights that FNA lung revealing keratinous material should always be searched for the possibility of teratoma component.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Testicular mixed germ cell tumor: A case report

BACKGROUND

Testicular mixed germ cell tumors (TMGCTs) are rare malignant tumors that are more common in men aged 20-40 years. TMGCTs comprise two or more types of germ cell tumors that primarily affect the testis. Their onset is undetectable; thus, early diagnosis is challenging. However, early recognition and diagnosis substantially improve patient prognosis.

CASE SUMMARY

We evaluated a rare case of TMGCT in a male patient presenting with recurrent fever and left supraclavicular lymphadenectasis instead of testicular enlargement and pain, which may easily lead to misdiagnosis. We report the clinical signs and symptoms, histopathological characteristics, and immunohistochemical results of this case of malignant TMGCT.

CONCLUSION

Our case, which was typical with multiple components, along with a literature review, may serve as a basis for early diagnosis.

The Polymorphisms in GSTO Genes (GSTO1 rs4925, GSTO2 rs156697, and GSTO2 rs2297235) Affect the Risk for Testicular Germ Cell Tumor Development: A Pilot Study

Members of the omega class of glutathione transferases (GSTs), GSTO1, and GSTO2, catalyze a range of reduction reactions as a part of the antioxidant defense system. Polymorphisms of genes encoding antioxidant proteins and the resultant altered redox profile have already been associated with the increased risk for testicular germ cell cancer (GCT) development. The aim of this pilot study was to assess the individual, combined, haplotype, and cumulative effect of GSTO1rs4925, GSTO2rs156697, and GSTO2rs2297235 polymorphisms with the risk for testicular GCT development, in 88 patients and 96 matched controls, through logistic regression models. We found that carriers of the GSTO1*C/A*C/C genotype exhibited an increased risk for testicular GCT development. Significant association with increased risk of testicular GCT was observed in carriers of GSTO2rs2297235*A/G*G/G genotype, and in carriers of combined GSTO2rs156697*A/G*G/G and GSTO2rs2297235*A/G*G/G genotypes. Haplotype H7 (GSTO1rs4925*C/GSTO2rs2297235*G/GSTO2rs156697*G) exhibited higher risk of testicular GCT, however, without significant association (p > 0.05). Finally, 51% of testicular GCT patients were the carriers of all three risk-associated genotypes, with 2.5-fold increased cumulative risk. In conclusion, the results of this pilot study suggest that GSTO polymorphisms might affect the protective antioxidant activity of GSTO isoenzymes, therefore predisposing susceptible individuals toward higher risk for testicular GCT development.

Long non-coding RNA TTTY14 promotes cell proliferation and functions as a prognostic biomarker in testicular germ cell tumor

Testicular germ cell tumors (TGCTs) commonly occur in males between the ages of 15 and 34, accounting for 98% of testicular malignancies. Long non-coding RNAs (LncRNAs) have been reported to play important roles in TGCT proliferation, invasion, and functioned as prognostic biomarkers. Testis-specific transcript, Y-linked 14 (TTTY14), a long non-coding RNA localized on Chr Y q11.222, has been found to be a potential prognostic biomarker for laryngeal squamous cell carcinoma, gastric cancer, and osteosarcoma. The biological role of TTTY14 in TGCT is not well understood. In this study, we aim to clarify the biological role of TTTY14 in TGCT, as well as its role in TGCT survival prognosis and immunotherapy efficacy prediction through the deep mining of public data combined with the verification of cell biological experiments. We found that high TTTY14 expression was a poor survival prognostic factor in TGCT patients and the expression of TTTY14 might be regulated by copy number variation and DNA methylation. TTTY14 knockdown significantly inhibited the proliferation of TGCT in vitro. TTTY14 expression was positively correlated with immune cell dysfunction, and significantly negatively correlated with B cells, CD8⁺ T cells, and macrophages, suggesting that TTTY14 may also affect the drug sensitivity by regulating the tumor immune microenvironment. In conclusion, we revealed that lncRNA TTTY14 was a novel oncogene and a biomarker in TGCT. TTTY14 may influence the drugs sensitivity through regulating the tumor immune microenvironment.

An Aberrant Seminoma as a Complication in an Undescended Testis: A Case Report and Review of Literature

Testicular germ cell tumors are testicular neoplasms in young and middle-aged men. Undescended testis dramatically increases the risk of testicular germ cell tumors. We report the case of a 33-year-old male who complained of swelling and pain in his lower abdomen. The patient also had an undescended left testis. An intrabdominal mass was detected on ultrasound that was further characterized using contrast-enhanced CT. Imaging findings suggested testicular germ cell tumor, developing as a complication in the undescended testis. The patient was operated and the diagnosis was confirmed on histopathological examination.

A first look into radiomics application in testicular imaging: A systematic review

The aim of this systematic review was to evaluate the state of the art of radiomics in testicular imaging by assessing the quality of radiomic workflow using the Radiomics Quality Score (RQS) and the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). A systematic literature search was performed to find potentially relevant articles on the applications of radiomics in testicular imaging, and 6 final articles were extracted. The mean RQS was 11,33 ± 3,88 resulting in a percentage of 31,48% ± 10,78%. Regarding QUADAS-2 criteria, no relevant biases were found in the included papers in the patient selection, index test, reference standard criteria and flow-and-timing domain. In conclusion, despite the publication of promising studies, radiomic research on testicular imaging is in its very beginning and still hindered by methodological limitations, and the potential applications of radiomics for this field are still largely unexplored.

Bilateral Testicular Burkitt's Lymphoma in a Child

Primary non-Hodgkin's lymphoma (NHL) represents less than 5% of testicular malignancies and most often occurs in elderly men (>60 years old). We present a case of a 6-year-old boy who presented with bilateral, painless testicular swelling. Imaging studies showed bilateral heterogenous infiltrative process without focal mass. Serum testicular tumor markers were negative. Incisional testicular biopsies revealed a highly aggressive metastatic Burkitt's lymphoma with involvement of the pancreas and bone marrow. Chemotherapy was initiated with good response and showed resolution of the testicular lesions.

Testicular Germ Cell Tumours—The Role of Conventional Ultrasound

Testicular tumours are the most common tumours found in young males and germ cell tumours account for 95% of testicular tumours. Ultrasound is the first-line radiological investigation for imaging of the testis. This article outlines how to undertake an ultrasound examination, including optimal patient position, scanning technique and imaging parameters. Classification of germ cell tumours is provided, and salient imaging features of different tumours are described. Difficulties and pitfalls of ultrasound are described, including tumours found after a trauma presentation, orchitis causing diagnostic difficulties and imaging of small testicular lesions. Other uses of ultrasound are outlined, including looking for a primary testicular tumour following the discovery of retroperitoneal lymph nodes, imaging when tumour-makers increase, local recurrence in the scrotum, and for solid organ biopsy in metastatic disease. Conclusion: Ultrasound remains the first-line of investigation for imaging of the testis, and conventional ultrasound still plays a large role in imaging. On ultrasound alone, accurate morphological characterisation of tumours remains a challenge, despite the imaging features that can be seen in different tumour types. Therefore, histology following orchidectomy of a germ cell tumour remains the gold standard for accurate tumour characterisation.

A massive retroperitoneal mature teratoma from a "burned-out" testicular teratoma and seminoma

Germ cell tumors are the most common nonhematologic malignancy of young men which often present with metastasis to the retroperitoneum, however a primary retroperitoneal mass should also be considered. The case presented herein reports a 42-year-old male presenting with a massive heterogenous retroperitoneal mass determined to be a mature cystic teratoma. Further investigation revealed a multifocal right testicular mass containing both a viable pure seminoma and a fibrous scar demonstrating germ cell neoplasia in situ thus representing the rare phenomenon of a "burned-out" mixed germ cell testicular tumor. When the radiologist is faced with a large retroperitoneal fat-containing mass, the differential includes a renal angiomyolipoma, liposarcoma, or germ cell tumor (whether primary or secondary). If pathology reveals a germ cell tumor, it is imperative to perform a thorough evaluation of the gonads, as it is much more common for a retroperitoneal germ cell tumor to be a metastasis from the gonads, rather than primary in origin.