Abstract
A 48-year-old woman with hepatomegaly, mitral stenosis, fibrillation, hypothyroidism and pernicious anemia, was exposed to I131 and Co60-labelled vitamin B12. In 3 months she developed polycythemia (hemoglobin, 20 g; hematocrits, 58%. After 5 venesections during the course of a year, the blood range became normal.