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

Area of Science:

• Oncology
• Pathology
• Radiology

Background:

• Testicular germ cell tumors (TGCTs) exhibit significant heterogeneity in histopathology, genetics, and clinical behavior.
• Most TGCTs originate from germ cell neoplasia in situ (GCNIS), a precursor with multipotent differentiation potential.
• The 2016 World Health Organization (WHO) classification distinguishes TGCTs into two pathogenetically distinct groups based on origin from GCNIS.

Purpose of the Study:

• To review the histopathologic, genetic, and immunocytochemical characteristics of TGCTs.
• To highlight the role of molecular testing and advanced imaging in TGCT diagnosis and management.
• To discuss the implications of the 2016 WHO classification on TGCT diagnosis, treatment, and prognosis.

Main Methods:

• Review of pathologic examination and genetic findings in TGCTs.
• Analysis of molecular testing for chromosome 12p amplification to differentiate tumor categories.
• Evaluation of imaging techniques (US, CT, MRI, PET/CT) for diagnosis, staging, and surveillance.

Main Results:

• TGCTs are categorized into GCNIS-derived (postpubertal) and non-GCNIS (prepubertal) groups, distinguished by 12p amplification.
• Advanced imaging modalities are crucial for diagnosis, staging, complication assessment, and treatment response evaluation.
• Seminomas respond well to chemotherapy/radiation, while teratomas are resistant, impacting therapeutic strategies.

Conclusions:

• Accurate diagnosis of TGCTs, guided by the 2016 WHO classification, is critical for effective treatment and prognosis.
• Radiologists play a vital role in the optimal management of patients with TGCTs.
• New treatment and follow-up guidelines have been developed based on updated classification and understanding of TGCTs.