Masked polycythemia vera due to iron deficiency anemia.

A 74-year-old Japanese woman was referred to our hospital for leukocytosis that occurred for the past one year. Oral iron supplementation was started as iron deficiency anemia (IDA), but three months later, physical examination revealed flushing of the skin on her hands. Finally polycythemia vera (PV) with IDA was diagnosed. There have been reports of PV combined with IDA, which can mask diagnosis and delay treatment because of the lack of symptoms and the anemic presentation. Several possibilities for the pathogenesis of IDA associated with PV have been proposed, including the presence of Helicobacter pylori.