A 30-year-old male farmer presented with fatigue and weight loss 2 years ago, with splenomegaly noted at a local clinic. He took 10 doses of Chinese herbal medicine without further evaluation. Over the past month, he developed fever, dizziness, bone and joint pain, and petechiae. Examination revealed an anemic appearance, cervical lymphadenopathy, sternal tenderness, liver 2 cm below the costal margin, and spleen 2 cm below the umbilicus. Lab tests showed decreased red blood cells (RBC) and platelets (PLT), elevated white blood cells (WBC), and bone marrow smear with blasts and immature lymphocytes accounting for 82%. The most likely diagnosis is: