Journal of the Medical Association of Thailand Vol 94, No 2:FEBUARY 2011 (SUPPL.1) 0125-2208 94 2 2011 Feb Incidence and Risk Factors of Bone Marrow Involvement by Non-Hodgkin Lymphoma 239 EN Janejira Kittivorapart Yingyong Chinthammitr Original Article Data from 320 patients with NHL at division of hematology between January 2008 and June 2009were reviewed and analyzed. The cell types of NHL were classified as B-cell in 283 patients (88.4%), T-cell in 37 patients (11.6%) and incidenceof BMI is 24.4% and 18.9% in B- and T-cell, respectively. Factors significantly associated with BMI in univariate analysiswere the hepatic and splenic involvement (p = 0.03 and < 0.01, respectively), significant weight loss (p = 0.02), presence oflymphadenopathy (LN) below diaphragm (p = 0.02), anemia (p = 0.001), low percent of blood neutrophil (p < 0.001), highpercent of blood lymphocyte (p < 0.001), low absolute neutrophil count (p = 0.002), high absolute lymphocyte count (p =0.045), low platelet count (p < 0.001), high LDH (p = 0.026), and high alkaline phosphatase (p = 0.020). On the multivariateanalysis, factors associated with BMI included LN below diaphragm, anemia, low percent of blood neutrophil and low plateletcount. Excluding Burkitt lymphoma and mantle cell lymphoma, NHL patients with no LN below diaphragm, no hepatic &splenic involvement, no significant weight loss, hemoglobin (Hb) >11 g/dL and platelet > 150,000/uL had BMI in 3/78(3.8%). The incidence of bone marrow involvement in NHL is 23.8%. Excluding Burkitt lymphoma and mantle celllymphoma, NHL patients with no LN below diaphragm, no hepatic & splenic involvement, no significant weight loss, Hb >11 g/dL and platelet >150,000/uL had low risk of BMI. Bone Marrow Non-Hodgkin Lymphoma