Abstract: Objective Through the cooperation Chinese Children's Leukemia Group (CCLG) members, to compare the diagnosis comprehensive level of bone marrow cell morphology in child with acute lymphocytic leukemia (ALL) in these hospitals, in order to assess and standardize the cell morphology determination method, unify terminology, improve the identification ability of bone marrow cell morphology. Methods A total of 110 children with ALL were enrolled randomly from the hospitals of CCLG. These hospitals provided the bone marrow smear of every child with newly diagnosed, treatment for 15th d, 33rd d and 12 weeks, respectively. Totally, there were 440 samples. These smears were randomly issued to 2 inspectors to reexamine. The review reports and original reports were compared and analyzed by another hematologist. Results Out of these 440 bone marrow smears, the consistent judgment was described in both review reports and original reports in 427 cases(97.0%). Of the other 13 cases(3.0%), the review reports showed the dilution of bone marrow aspiration without the description of bone marrow hyperplasia grade, but the original reports showed good aspiration of bone marrow with bone marrow hypoplasia. Good staining of bone marrow smear was described in both review reports and original reports in 428 cases(97.3%). Light or deep staining was showed in the other 12 cases(2.7%), but in the original reports, they showed good staining. In the procedure of describing the character of bone marrow, both the review and original reports were showed no standard terms with Sino-English language mixing, without standard Chinese and English abbreviation. The conclusions of bone marrow smear in the review and original reports were consistent in 427 cases(97.0%), except for the other 13 cases with objection in the aspiration of bone marrow between the 2 reports. Conclusions The comparison analysis of bone marrow smear in children with ALL in multicenter is a very important attempt and exploration to improve the diagnosis level of bone marrow cell morphology, establishes a standardized cell morphology determination pattern, unify terminology, and improve the report recognition degree.

Key words: Bone marrow cell, Morphology, Acute lymphocytic leukemia, Child