Bone marrow response to chemotherapy in acute lymphocytic leukaemia and acute non-lymphocytic leukaemia.

Histopathologic changes in core bone marrow biopsies were reviewed in 33 patients with acute leukaemia during chemotherapy to compare the changes in acute lymphocytic leukaemia (ALL) with acute non-lymphocytic leukaemia (ANLL). Cellular, stromal, and bony changes were evaluated with regard to diagnosis and time of biopsy from initiation of chemotherapy. A significant difference was noted in the plasma cell response. Plasmacytosis was present in 19/19 cases of ANLL, but in only 2/14 cases of ALL. Cellular depletion was also significantly less frequent in ALL. Other stromal changes such as haemorrhage, dilatation of sinusoids and fat regeneration, as well as osteoblastic bone activity occurred with similar frequencies in all cases of treated acute leukaemia. Fibrosis, necrosis, and serous atrophy were uncommon. Differing chemotherapeutic regimens and differing patient ages were both correlated with the plasma cell response, but not with the difference in cellular depletion.