A 2 yo female presented with persistent fever and massive hepatosplenomegaly. CBC revealed marked leukocytosis (WBC 102,000/uL, 1.5% immature granulocytes, 14.2% bands, 64.9% segmented neutrophils, 16.4% lymphocytes and 3% monocytes), anemia (hemoglobin, 5.8 g/dL) and thrombocytopenia (platelet count, 59,000/uL).
PB: : Markedly increased neutrophils with toxic granulation and cytoplasmic vacuoles, occasional myelocytes and metamyelocytes, few medium to large sized atypical lymphoid cells with round or irregular nuclei and basophilic vacuolated cytoplasm, no blasts.
BM: Granulocytic hyperplasia with few atypical lymphoid cells same as seen in PB, no increase of blasts..