Autologous blood-derived stem cells were used for stem-cell rescue in a 5-year-old boy with chemotherapy-resistant B-Non-Hodgkin's lymphoma (B-NHL) involving bone marrow. The high dose chemoradiotherapy was carried out 5 months after initial diagnosis during partial remission. The preparative regimen consisted of 12 Gy fractionated, total-body irradiation (FTBI) before 60 mg/kg etoposide. There were 22.96 X 10(4)/kg body weight myeloid precursor cells, granulocyte-macrophage committed stem cells (CFU-GM) collected by intermittent blood flow separation with a Haemonetics 30R in two cytaphereses and stored in liquid nitrogen. Also 11, 82 X 10(4) CFU-GM/kg body weight were recovered and transfused after thawing. Rapid hematopoietic reconstitution ensued: Erythroid precursors were detected on day 9, 1 X 10(9)/L leucocytes were counted on day 11, and 0.5 X 10(9)/L granulocytes on day 13, respectively. The patient required 3 single-donor platelet transfusions, the last one on day 10. On day 17, 100 X 10(9)/L platelets were reached. A bone marrow aspirate on the same day showed good trilineage regeneration. The patient remained in complete remission 7 months after autografting with a normal stem cell content of the bone marrow and in the peripheral blood. On day 226, after stem cell infusion, a bone marrow relapse occurred.