is a malignant (cancerous) condition involving the testis.The usual treatment is operative removal of the tumor and chemotherapy
However, this tumor can spread to other parts of the body (commonest to lymph nodes in the para-aortic region). Your MRI report indicated the development of new changes in the vertebra as well as para-aortic lymph nodes when compared to the previous scan. In most probability this could mean that the tumor has spread to other parts of the body. A bone scan (nuclear scintigraphy
like PET scan) may help detect further spread to any other parts of the body like chest, brain, etc.
It would be advisable to meet your oncologist
at the earliest to discuss treatment options. Most probably you would be advised another course of chemotherapy, probably with different drugs this time. Even, metastatic testicular tumors
have a reasonably better prognosis when compared to some tumors in other parts of the body.