Fig. 1.

Refractory cytopenia of childhood (RCC) with variable bone marrow cellularity. Most patients exhibit hypocellular bone marrow for their age (A). In some patients, hypercellular areas are present in the marrow (B). The distribution of hematopoiesis depends on the marrow cellularity. A patchy distribution is likely seen in the hypocellular marrow (C), whereas a diffuse distribution is often present in hypercellular marrow (D). Naphthol ASD chloroacetate esterase plus Giemsa double-staining (ASD-Giemsa). (A, B) ×40; (C, D) ×400.