Risk Assessment in Testicular Tumors (Including Germ Cell And Sex Cord Stromal Tumors).

Testicular tumors are relatively rare, yet represent one of the most common solid neoplasms in young adult males. They are a heterogeneous group of neoplasms with distinct biological behaviors and can be diagnostically challenging due to their relative unfamiliarity. The vast majority are of germ cell origin [testicular germ cell tumors (TGCTs)], predominantly arising from the precursor lesion, germ cell neoplasia in situ (GCNIS), and are broadly classified as seminomas or nonseminomas. TGCTs are highly curable, with efforts focused on reducing treatment intensity. The second most common group of testicular neoplasms is sex cord-stromal tumors (SCSTs). These usually follow a benign clinical course, but 5% to 10% are malignant and metastasize. In contrast to TGCTs, SCSTs are largely unresponsive to chemotherapy and radiotherapy; therefore, surgical resection, such as early retroperitoneal lymph-node dissection, may be the only effective treatment. Accurate tumor classification, staging, and risk stratification of TGCTs and SCSTs have a profound effect on patient care and rely on a thorough histopathologic examination, from macroscopic evaluation to microscopic assessment. In this review, we summarize the clinicopathological features most relevant and robust for the prognostication of patients with testicular tumors, with a focus on practical guidance on reporting and the avoidance of diagnostic pitfalls. Recent molecular insights that refine classification and predict clinical outcomes are also discussed.