Thank you. This is called a pancytopenia which can arise from primary bone marrow disease or disorders that affect the bone marrow. With diffuse marrow involvement, white blood cells are affected first, followed by platelets and finally red blood cells. Here are the specific diseases I see:
1) Aplastic anemia: Pancytopenia and a hypoplasic (under or incomplete development) marrow replaced by fat is seen. Most cases are idiopathic (unknown cause) but reported causes include infection (parvovirus, Ehrlichia), drug therapy such as antibiotics (trimethoprim-sulfa, chloramphenicol) and fenbendazole, and toxic ingestions (estrogens, e.g.).
2) Myelodysplasia: This is considered a preleukemic syndrome characterized by ineffective hematopoiesis (red blood cell production) resulting in a nonregenerative anemia and other cytopenias (thrombocytopenia/low blood platelets and leukopenia/low white blood cells). This disease can be primary or secondary. Primary syndromes probably arise from mutations in stem cells. Secondary syndromes are caused by neoplasia (cancer) or drug therapy.
3) Myelofibrosis: This causes bone marrow failure secondary to replacement of normal marrow elements with fibrous tissue. It can be a primary disorder or secondary to malignancies, immune-mediated hemolytic anemia, and congenital anemias (e.g., pyruvate kinase deficiency.
Bone marrow biopsy is necessary to clarify which of the above exists. If we can rule out drug toxicity, either a congenital (present at birth) and genetic disorder or idiopathic immune-mediated destruction of her bone marrow is most likely. Please continue our conversation if you wish.