Megakaryocytes in chronic myeloproliferative disorders: Numerical density correlated between different entities

Abstract

A morphometric evaluation of number and grouping of megakaryocytes (MK) in five different groups of chronic myeloproliferative disorders (CMPD) was performed by counting 60 high power fields equaling approximately 14.28 mm2 of haematopoiesis in each case. Twenty-one up to 29 cases were evaluated for each of five categories of CMPD and one control group; a total of 132 cases of CMPD and 33 control cases were used. The mean number of MK per square millimetre was 15.54 +/- 1.53 in chronic myeloid leukaemia of common or granulocytic type (CML.CT), 69.91 +/- 5.85 in CML with megakaryocytic increase (CML.MI), 59.59 +/- 3.27 in polycythaemia vera (P. vera), 59.85 +/- 4.59 in primary thrombocythaemia (PTH), 67.58 +/- 4.11 in chronic megakaryocytic granulocytic myelosis (CMGM), and 19.7 +/- 3.07 in controls. The distinction between free or isolated MK, and between clustered or grouped MK corresponds to the total cell counts of MK in the various groups of CMPD. Clustering of MK was significantly higher in CMGM and PTH compared to other groups, but the difference between them was not statistically significant. Significant differences in the mean number of MK were obtained between controls and CML.CT on the one hand and all other groups of CMPD on the other. The results further support the histological sub-classification of CMPD according to the primary disorders of the Hannover classification (not advanced by sclerosis, fibrosis or excess of blasts, respectively).

Histochemistry and morphometry on bone marrow biopsies in chronic myeloproliferative disorders - aids to diagnosis and classification

“…As in the other subtypes of MPDs, there is a significant disturbance of histotopography, implying an obvious dislocation of megakaryopoiesis from the centers of the marrow space to the paratrabecular-endosteal areas. On the other hand, in IMF not only an increase (Table 1) together with clustering and histotopographical pathology [25,44,49], but also a conspicuously abnormal deviation of maturation, i.e., hematopoietic dysplasia, is seen (Fig. 3b).…”

“…Not only a striking increase in CD61 c -megakaryopoiesis [19,25,41] throughout the bone marrow characterizes PV (Table 1), but also an abnormal clustering of these cells and a pleomorphous aspect [2,7,20,21,42,51]. This peculiar appearance consists of a grouping of giant megakaryocytes with hyperlobulated staghornlike nuclei together with medium to small and degenerative cell forms or naked nuclei (Fig.…”

Proposal for Revised Diagnostic Criteria of Essential Thrombocythemia and Polycythemia Vera by the Thrombocythemia Vera Study Group

“…With the advent of bone marrow biopsy and tissue processing, the German pathologists Burkhardt, Georgii, and Thiele and many others have drawn attention to the importance of histopathology from bone marrow sections for the diagnosis of the various MPDs. 6,[37][38][39][40][41][42][43][44][45][46][47][48][49] The number and size of mature megakaryocytes in bone marrow biopsies are typically increased in ET and PV. Large megakaryocytes with mature cytoplasm and multilobulated nuclei, and the tendency of such megakaryocytes to cluster in small groups close to sinuses represent the hallmark feature of ET.…”

Essential Thrombocythemia in Childhood

“…Both the number and size of mature megakaryocytes are typically increased in ET and in PV. [10][11][12][13][14] Large megakaryocytes with mature cytoplasm and multilobulated nuclei and their tendency to cluster in small groups close to sinuses is suggested to represent a hallmark of ET. The histologic background is featured by normal cellularity in the early stage.…”