An ultrastructural morphometric analysis of platelet giant and fusion
granules
CM Payne and L Glasser
Our purpose in this study was to establish ultrastructural morphometric
criteria that can be used to define pathologic giant and fusion platelet
granules and to determine whether patients with neoplastic
myeloproliferative disorders (MPD) can be distinguished from other
patients. We have morphometrically analyzed 2,391 giant and fusion granule
profiles from 46 patients with neoplastic MPD, 127 other diseased control
subjects, and 30 normal subjects using a computerized image analyzer. The
largest granule profile observed in normal subjects had an area of 0.51 mu
2 and a perimeter of 3.21 mu. The most irregularly shaped of the large
granule profiles photographed from normal subjects had a form factor (FF)
value of 0.31. FF values indicate the degree of deviation of a given
granule contour from a circle and is expressed by the formula 4 pi A/P2. A
pathologic granule profile was then defined as a granule that exceeded any
of these limits. Fifty-seven percent of the patients with neoplastic MPD
were determined to have abnormal platelet granule profiles using the
aforementioned morphometric criteria. It was determined, however, that
morphometrically defined giant- and fusion-type granule profiles were
nonspecific and were also found in 20% of the other diseased patients with
no clinical evidence of an underlying neoplastic MPD. Morphometry has
allowed us to define the upper limits of normal for the area and perimeter
of individual platelet granules. Morphometrically defined giant fusion
granules were determined to be more prevalent in the neoplastic MPD group,
but because of their nonspecificity, may only have diagnostic significance
for the individual patient in specific clinical settings. The pathogenesis
of platelet fusion granules is discussed.
Volume 67,
Issue 2,
pp. 299-309,
02/01/1986
Copyright © 1986 by The American Society of Hematology
