Testicular histology after combination chemotherapy in childhood for acute lymphoblastic leukaemia.

A study of testicular histology has been made in 44 boys treated with combination chemotherapy for acute lymphoblastic leukaemia. At the time of testicular biopsy 21 boys were still receiving cytotoxic drugs and 23 had completed their chemotherapy some time earlier. Evidence of leukaemic infiltration was seen in 5 (11%), interstitial fibrosis in 24 (55%), and basement-membrane thickening in 6 (14%). The mean tubular fertility index in the 44 biopsies was 50% of that in age-matched controls, and 18 of the biopsies had a severely depressed tubular fertility index (40% or less). Three variables had a highly significant effect on the tubular fertility index: previous therapy with cyclophosphamide or cytosine arabinoside (greater than 1 g/m2) depressed the tubular fertility index, whereas with increasing time after completion of chemotherapy the tubular fertility index improved. The prognosis for fertility in these subjects is not known. Long-term surveilance is necessary.