Splenic Rupture of AML M2 Fig. 1. Computed tomography (CT) image of the upper abdomen demonstrates multiple splenic lacerations evidenced by the irregular, non- homogeneous, low density of splenic body (red arrows). C C A A B B Fig. 2. (A) The spleen shows blood clots attached to the ruptured capsule (H-E stain, ×20). (B) The spleen evidences diffuse invasion by immature myeloid cells (H-E stain, ×200). (C) The infiltrates are composed principally of myeloperoxidase-positive immature myeloid cells (Myeloperoxidase stain, ×400). Fig. 3. (A) This section shows hypercellular marrow with a cellularity of 70-80% and a diffuse infiltration of leukemic blasts (H-E stain, ×400). (B) Leukemic blasts tested positive for myeloperoxidase (Myeloperoxidase stain, ×1,000). (C) Leukemic blasts tested positive for PAS (PAS stain, ×1,000). of 22,000/µL. On his disseminated intravascular coagulo- pathy (DIC) profile, prothrombin time (PT) 1.2, internatio- nal normalized ratio (INR), activated partial thrombo- plastin time (aPTT) 27.6 seconds, fibrinogen 254 mg/dL, Fibrinogen degradation product (FDP) 75.8 µg/mL, and D- dimer > 16 µg/mL - these findings suggested DIC. He transfused 10 units of packed red blood cell (RBC) (320 mL) and 30 units of platelet concentrates (320 mL) for operation. The patient’s peripheral blood smear showed neutrophilic leukocytosis with leukoerythroblastosis, microcytic anemia, and marked thrombocytopenia. The patient was subjected to a bone marrow biopsy examination. The bone marrow examination revealed a hypercellular marrow of approxi- mately 70-80% cellularity. Normal myelopoiesis and erythropoiesis were both depressed, and no megakary- ocytes were observed. We noted a marked proliferation of leukemic blasts, 48.6% of all nucleated cells, characterized by a high nuclear/cytoplasm ratio, fine nuclear chromatin, several distinct nucleoli, irregular nuclear and cytoplasmic membranes, and occasional cytoplasmic granules (Fig. 3). The leukemic blasts were shown to be positive for CD13, CD33, and CD56, and were also positive for MPO and PAS. Conventional cytogenetic analysis on the G-banded metaphases revealed the following: 46,XY,der(7)t(7;9) (p22;p21)inv(9)(p12q 13),der(9)t(7;9)inv(9). The results revealed AML of M2 subtype. Yonsei Med J http://www.eymj.org Volume 51 Number 1 January 2010 139