Primary testicular B-lymphoblastic lymphoma is a rare entity. Primary testicular Ph-positive B lymphoblastic lymphoma was not reported before. We reported a 27-year-old man with primary testicular Ph-positive B lymphoblastic lymphoma, for which fluorescent in-situ hybridization (FISH) for the Philadelphia chromosome was not performed at the initial hospitalization. The patient showed manifestation of Ph-positive acute lymphoblastic leukemia at relapse. In this report, we reviewed the current literature about primary testicular B-lymphoblastic lymphoma, Ph-positive lymphoma and Ph-positive clone evolution. This report has 3 meanings. First: This is first report on primary testicular Ph-positive B lymphoblastic lymphoma. Second: This shows the importance of cytogenics for lymphoma treatment. Third: This implies Philadelphia-positive subclone evolution.