Chronic obstructive pulmonary disease (COPD) can be accompanied by com
pensatory secondary erythrocytosis. However, the exact prevalence of s
econdary erythrocytosis in COPD is unknown. Although diagnostic criter
ia for polycythemia vera versus secondary erythrocytosis are mutually
exclusive, we describe here the coexistence of polycythemia vera and C
OPD in the same patient. (C) 1998, Ferrata Storti Foundation.