1Laboratoire d'Hématologie, Centre Hospitalier Universitaire (CHU) de Bordeaux, Bordeaux, France.
2Laboratoire d'Hématologie, Grand Hôpital de l'Est Francilien, Meaux, France.
A 4-year-old boy presented with spontaneous hematomas, lower limb pain, fever, and hepatosplenomegaly. A complete blood count revealed pancytopenia (white blood cells, 7.6×109/L; neutrophils, 0.46×109/L; hemoglobin, 6.7 g/dL; platelets, 85×109/L). The peripheral blood smear examination showed 54% medium-sized blasts, with a high nucleus-to-cytoplasm ratio, round or oval nuclei, fine chromatin, and basophilic cytoplasm containing many vacuoles. The bone marrow (BM) was infiltrated by 98% of blasts of the same morphology. Interestingly, we frequently observed thrombophagocytosis and erythrophagocytosis by blasts in the BM (composite image of BM smear, May-Grunwald-Giemsa staining, ×1,000;