A 12-year-old boy presented with epistaxis, mild bruising, intermittent bone pain, and massive splenomegaly

(A). Gaucher disease is a multisystemic lipidosis characterized by hematologic abnormalities, organomegaly, and skeletal involvement, the latter usually manifesting as bone pain and pathologic fractures. It is one of the most common lysosomal storage diseases, results from the deficient activity of the lysosomal hydrolase, acid B-glucosidase, which is encoded by a gene located on chromosome 1q21-q31. The pathologic hallmark of Gaucher disease is the Gaucher cell in the reticuloendothelial system, particularly in the bone marrow.