New challenges in evaluating anemia in older persons in the era of molecular testing.

Anemia is common in older persons, and often remains unexplained despite a thorough clinical history, physical examination, and focused laboratory testing, including marrow aspiration, biopsy, and karyotyping. The advent of molecular genetic testing panels in hematology clinical practice has complicated the evaluation of older patients with unexplained anemia. While the presence of a somatic mutation provides evidence of clonal hematopoiesis and may support a diagnosis of a hematologic neoplasm such as one of the myelodysplastic syndromes (MDS), with rare exceptions, individual mutations are not strongly associated with one specific diagnosis, nor are they by themselves diagnostic of neoplasia. A clonal mutation in a patient with cytopenias and a nondiagnostic bone marrow may indicate a syndrome with a similar natural history to MDS, but at present there are no clear criteria to distinguish cytopenias coincidentally seen in association with an unrelated clonal mutation from cytopenias that are directly caused by that mutation. Ongoing and planned analyses will help define when mutation patterns alone can identify a disorder equivalent to a morphologically defined myeloid neoplasm such as MDS, further clarifying the etiology and natural history of unexplained anemia in the elderly.