What does it mean if a bone marrow biopsy/aspiration report shows hypocellular marrow?

Hypocellular marrow: The normal bone marrow is a mixture of cells and fat. Hypocellular marrow means the marrow has fewer cells in the bone marrow space that is expected for that patient's age. There are many causes for this including nutritional deficiencies, bone marrow failure syndomes, pre-leukemia (myelodysplasia), prior chemotherapy, toxins and medications.