Morphological metamorphosis in relapsing lymphoblastic leukemia.

Publisher Website
Google Scholar
Abstract
Blast cell morphology was assessed at diagnosis and subsequent bone marrow relapse in 33 unselected patients with lymphoblastic leukemia (ALL). Each marrow was classified blind according to the French-American-British (FAB) criteria; 19 of 24 (79%) patients initially typed as FAB L1 changed to FAB L2 during the course of their disease, but no patient made the reverse morphological change (P < 0.001). Five patients retained FAB L1 appearances; these included 3 of the 4 who had T-cell markers. One patient typed as FAB L3 did so consistently. FAB L2 ALL may frequently emerge as a treatment-resistant offshoot of FAB L1. Further evidence that this marks a more aggressive form of the disease is provided.