en Pathology Pathology Original Research Original Research Bone marrow specimens from leukemic patients were studied in a 5 year period beginning in 1982 in Children's Medical Center of Teheran,a teaching and referral center for pediatric medicine. The slides were stained by Giemsa-Wright stains, read by at least two persons experienced in bone marrow pathology and classified according to F.A.B. recommendations. Peroxidase or Sudan black-B and P.A.S. reaction were used fordifferentiation of myeloblasts from lymphoblasts when required. Acute lymphoblastic leukemia is the most prevalent childhood leukemia in Iran, as it is in other countries, but the incidence is relatively lower compared to western countries. The percentage of all leukemic subtypes are almost similar to other reports except for L2, Ml and M2 where L2 has a relatively lower occurrence with Ml and M2 being more prevalent. 263 264 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-475&slc_lang=en&sid=1 AA POURFATHOLLAH 20031947532846005560 20031947532846005560 Yes From the Tarbiat Modarres University', Department of Pathology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences M RAKHSHAN 20031947532846005561 20031947532846005561 No and the Departments of Pathology and Hematology, Children's Medical Center. Tehran University of Medical Sciences M AHMADI 20031947532846005562 20031947532846005562 No M IZADYAR 20031947532846005563 20031947532846005563 No