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

Testicular germ cell tumors (TGCTs) demonstrate a wide variety of histopathologic, genetic, pathogenetic, and immunocytochemical characteristics and various clinical-biologic profiles and prognoses. Most TGCTs arise from an intratubular precursor cell referred to as germ cell neoplasia in situ (GCNIS), which is an embryonic germ cell with the potential to differentiate into a plethora of embryonic and extraembryonic lineages. Advances in pathologic examination and genetics paved the way for the 2016 World Health Organization (WHO) classification system, which recognizes two pathogenetically distinct groups of TGCTs.