[ Polyglobuly versus polycythemia vera].
Differentiation of an elevated hemoglobin/hematocrit level warrants not only the determination of relevant laboratory values, including erythropoietin, but also an elaborate evaluation of bone marrow histopathology. Particularly in the initial stages of polycythemia vera (PV), when not all stringent clinical criteria are completely fulfilled, a more refined analysis of morphological features helps to distinguish autonomous (PV) from spurious or secondary erythrocytosis - polyglobuly (PG). PV is characterized by a panmyelosis, i.e., a trilinear proliferation of all cell lineages, whereas in PG erythropoiesis predominates. Megakaryopoiesis exerts a significant impact on differentiation, because in PV there is a conspicuous grouping associated with a strikingly expressed pleomorphous appearance. This peculiar feature implicates assemblies of small- to medium-sized megakaryocytes lying adjacent to giant cells with extensively lobulated, staghorn-like nuclei. A further discriminating parameter is presented by the interstitial lesions frequently occurring in PG. These, according to the usually underlying inflammatory cause (chronic bronchitis-recurrent bronchopneumonias), include iron-laden macrophages, a prominent perivascular plasmacytosis, phagocytosis of cell debris by histiocytic reticular cells and often an in- crease in the number of eosinophils. Comparable findings are not, or only to a minor ex-tent, detectable in PV. In conclusion, by regarding hematopoiesis and the myeloid stroma initial stages of PV may be definitively distinguished from PG.
Thiele
J
J
Zentrum für Pathologie der Universität zu Köln.
Kvasnicka
H M
HM
D001853:Bone Marrow / Q000473:pathology*; D003937:Diagnosis, Differential; D004921:Erythropoietin / Q000097:blood; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000145:classification / Q000473:pathology*; D006801:Humans; D011086:Polycythemia / Q000097:blood / Q000473:pathology*; D011087:Polycythemia Vera / Q000097:blood / Q000473:pathology*
D004921:Erythropoietin