IMAGE-ANALYSIS DETECTS LINEAGE-SPECIFIC MORPHOLOGIC MARKERS IN LEUKEMIC BLAST CELLS

This report outlines the morphologic classification of acute myeloid ( AML: French-American-British FAB classification: M1) and lymphoid (ALL ) leukemia by automatic image analysis and the correlation to immunolo gic and cytochemical classification, The investigation was carried out on Romanowsky-Giemsa stained bone marrow (n = 15) and blood smears (n = 10) from 25 patients with primary acute leukemia. The cases had bee n classified as of myeloid or lymphoid origin by three hematologic cen ters using immunochemistry or cytochemistry, but the specimens were su bmitted to the authors' laboratory without the diagnosis. The nuclear and cytoplasmic pattern of the blast cells were analyzed by a high res olution image analysis system and the measured and calculated cell fea tures were sorted by means of a classifier program (CART), The image a nalysis classification was then compared with the immunophenotypical a nd cytochemical classification. Blood blast cells showed nuclear featu res that were significantly correlated to a myeloid or lymphoid immuno phenotype. In contrast, bone marrow blast cells displayed overlapping and therefore nondiscriminating nuclear features, However, by generati ng a learning data set using the immunophenotypes the classifier progr am found specific cytoplasmic features that eventually permitted a dif ferentiation into myeloid or lymphoid subtypes, In summary, the author s suggest that high resolution image analysis of leukemic blast cells detects nuclear and cytoplasmic features that are associated with the immunophenotype and therefore with the lineage determination of the ce ll. With this new objective and reproducible approach of morphologic c ell analysis, it might not only be possible to classify blast cells wi th minimal cellular differentiation, but furthermore to discover progn ostic features because the remarkable difference in classification qua lity between blood and bone marrow blast cells reported in this study, might be of biologic relevance and requires further investigation.