Thank you for your interest and your questions. I can't divine what the WHO experts were thinking (or not thinking), but they definitely had a problem when they a priori initially eschewed red cell mass (RCM) and plasma volume (PV) measurements for the diagnosis of PV because they didn't understand ...

Contrary to the contention of the WHO MPN "experts", a bone marrow biopsy is never indicated for the diagnosis of polycythemia vera (PV). By extension, a bone marrow biopsy is also not indicated to look for myelofibrosis (MF) in PV, since MF is a reactive and reversible event in PV, which does not i...