Isolated testicular relapse five years after cessation of chemotherapy for acute lymphoblastic leukemia.

A 12-year-old boy was diagnosed as having acute lymphoblastic leukemia (ALL) at the age of 2 years 10 months. Chemotherapy was discontinued after 33 months of continuous remission of ALL. Isolated testicular relapse occurred 5 years after cessation of treatment. Isolated testicular infiltration if it occurs, usually does so within one year after discontinuing treatment. Late bone marrow or extramedullary relapse usually does not occur after four years post therapy. Testicular relapse in this patient occurred five years after completing chemotherapy.