 Malignant testicular germ-cell tumors metastasize by either the hematogenous or lymphatic route. Nodal metastases typically follow the testicular lymphatic drainage pathway alongside the testicular veins to regional lymph node groups. Tumors from the left testis will metastasize to the left para-aortic nodal group just below the left renal vein and interaortocaval group, whereas right testicular tumors will metastasize to the paracaval, precaval, and interaortocaval groups. Crossover of lymphatic involvement may occur in either right-sided or left-sided tumors; however, it is unusual to have contralateral metastasis without involvement of the ipsilateral nodes [4]. Further spread to nonregional lymph node groups, including common iliac, internal iliac, and external iliac nodes, or via the thoracic duct to the left supraclavicular nodes and subsequently to the lungs, constitutes distant metastasis [5]. Prior scrotal or inguinal surgery can alter the lymphatic drainage; therefore, external iliac and inguinal lymph nodes are considered regional in that context [6]. Staging of testicular cancer is based upon determination of extent of disease and follows the tumor, nodes, and metastases (TNM) staging system used by the American Joint Committee on Cancer [5]. TNM staging of testicular cancer is a major factor that determines treatment and prognosis in men with testicular cancer. Imaging is used to assess for expected locations of lymph node involvement and metastatic disease. Most patients with stage IA and IB pure seminoma testicular cancers are cured by orchiectomy [7]. Surveillance is strongly preferred in this group of patients; however, because 15% to 20% of men experience relapse, adjuvant therapy with one or two cycles of single-agent carboplatin or radiotherapy to decrease risk of relapse can be considered in certain high-risk patients [8-11]. Irrespective of management strategy, disease-specific survival approaches 100% [8-11].
Staging and Surveillance of Testicular Cancer.  Malignant testicular germ-cell tumors metastasize by either the hematogenous or lymphatic route. Nodal metastases typically follow the testicular lymphatic drainage pathway alongside the testicular veins to regional lymph node groups. Tumors from the left testis will metastasize to the left para-aortic nodal group just below the left renal vein and interaortocaval group, whereas right testicular tumors will metastasize to the paracaval, precaval, and interaortocaval groups. Crossover of lymphatic involvement may occur in either right-sided or left-sided tumors; however, it is unusual to have contralateral metastasis without involvement of the ipsilateral nodes [4]. Further spread to nonregional lymph node groups, including common iliac, internal iliac, and external iliac nodes, or via the thoracic duct to the left supraclavicular nodes and subsequently to the lungs, constitutes distant metastasis [5]. Prior scrotal or inguinal surgery can alter the lymphatic drainage; therefore, external iliac and inguinal lymph nodes are considered regional in that context [6]. Staging of testicular cancer is based upon determination of extent of disease and follows the tumor, nodes, and metastases (TNM) staging system used by the American Joint Committee on Cancer [5]. TNM staging of testicular cancer is a major factor that determines treatment and prognosis in men with testicular cancer. Imaging is used to assess for expected locations of lymph node involvement and metastatic disease. Most patients with stage IA and IB pure seminoma testicular cancers are cured by orchiectomy [7]. Surveillance is strongly preferred in this group of patients; however, because 15% to 20% of men experience relapse, adjuvant therapy with one or two cycles of single-agent carboplatin or radiotherapy to decrease risk of relapse can be considered in certain high-risk patients [8-11]. Irrespective of management strategy, disease-specific survival approaches 100% [8-11].