Nuclear findings seen in leukocytes from women (or anyone with more than 1 X chromosome):
(1) drumsticks in neutrophils
(2) sessile nodules in neutrophils
(3) nuclear sex chromatin (Barr body) in lymphocytes and monocytes
Although a blood smear can be examined for nuclear sex chromatin (Barr body), artifacts occur and the examination requires a special stain. In addition, it may be difficult to distinguish from nuclear clumping in leukocytes.
Features of the drumstick:
(1) The bulbous end is dense and measures 1.5 microns in diameter.
(2) There is a thin nuclear filament connecting the end to the rest of the nucleus.
(3) There should only be 1 per PMN (the presence of more than 1 suggests artifact).
The sessile nodule has the bulbous end of the drumstick but is connected to the nucleus by a broad base.
Specimen: smear prepared from fresh capillary blood (oxalated blood may have more artifacts)
Number of PMNs to count when looking for drumsticks: 500 or more
percent of cells with nuclear drumsticks =
= (number of cells with drumsticks) / (number of polymorphonuclear leukocytes counted) * 100%
Interpretation:
• Most women have from 1-7% PMNs with drumsticks.
• Occasionally a woman may show down to 0.2% (1 in 500) PMNs with drumsticks.
• A woman with Turner Syndrome (XO) would not show drumsticks unless an XO/XX mosaic.
• A normal male should not have any drumsticks.
• Rarely a man may show a drumstick. However, the quantitation of sex chromosomes is needed to determine if the person has more than 1 X chromosome (XXY, XXXY, etc.)
• Rarely a male fraternal twin with a female twin will show a small number of drumsticks.
• A phenotypic female without drumsticks may have testicular dysgenesis.
Differential diagnosis (artifacts confused with drumsticks):
(1) racquets (have a cleared or hypodense center)
(2) small nuclear clumps
