Bone Marrow, Cytochemical, QC and QA,
A peripheral blood smear shows 75% blasts. These stain positive for both Sudan Black B (SBB) and myeloperoxidase. Given these values, which of the following disorders is most likely?
. Acute myelocytic leukemia (AML)
Westgard Rules
1(2s) 2 std dev 1(3s) 3 std dev 2(2s) second time at 2STD R(4s) one is +2s and other is -2s 4(1s)-four readings of one std dev difference on same side 10(x) -ten readings on one side of mean even if less than 1 SD
Bone marrow biopsy why?
1. Anemias or erythrocytosis 2. leukopenia, unexplained lymphocytosis 3. immature/abnormal 4. Thrombocytopenia/cytosis 5. metastatis diseases 6. Fever 7. Histocytosis Dry tap
Which of the following Westgard Rules is indicative of a shift?
10X
Which of the following QC rules would be broken one out of 20 times by chance alone?
12S
A patient's white blood cells (WBCs) are counted on an automated cell counter 10 times. The mean white count is 8000/mL, and the standard deviation (SD) is 300. What is the coefficent of variation (CV)?
3.8%
standard deviation
65-95-99.7
Periodic acid-Schiff (PAS)
Acute Lymphoblastic Leukemia- block pattern for malignant lymphoblasts Acute Myelogenous Leukemia (M6)-strong positive Normal Cells- diffuse stain erythroblasts = STRONG positive
Sudan black is used to distinguish which types of leukemia?
Acute myeloid leukemia from acute lymphoblasitc leukemia
When performing a bone marrow biopsy, the aspirate is a "dry tap". Which condition may be suspected based on this finding?
Aplastic anemia
Which of the following is true regarding reference ranges?
Are ranges of values for an analyte in normal healthy people in your patient population
For which of the following is obtaining a bone marrow core biopsy mandatory?
Aspirate is a dry tap
A purchased hemoglobin standard is used to adjust a hemoglobinometer. This standard is being used as a:
Calibrato
What bone marrow sample is best to determine fat-to-cell ratio and overall cellularity?
Core biopsy
What type of bone marrow aspirate smear preparation is preferred for preforming bone marrow cell differentials?
Coverslip smears containing a bone marrow fragment called a spicul
The sites of active red marrow differ for adults and young children. Which one site is active in children but not in adults?
Distal ends of the long bone
Tartrate Resistant Acid Phosphatase (TRAP)
Hairy cell leukemia (B cell neoplasm)
Tartrate-resistant acid phosphatase is strongly positive in which of the following cells?
Hairy cells
Which of the following assays has the poorest precision?
Hematocrit %
A patient specimen is analyzed on an instrument known to be in control and recently calibrated. The instrument gives a hemoglobin result of 13.2 g/dL. Two hours later the same specimen is evaluated on another instrument that is being evaluated for purchase by the laboratory. The result is 11.1 g/dL. This result, when compared with the first, is:
Inaccurate
What cells may demonstrate a coarse block pattern of activity with the PAS stain?
Malignant lymphoblasts
Low power (x10) is used to count and evaluate which of the following?
Megakaryocytes
Which of the following would stain most strongly for myeloeroxidase?
Myeloblasts
One of two control within a run is above +2s and the other control is below -2s from the mean. What do these results indicate?
Poor precision has led to random error
When running the controls on your Point of Care hemoglobin analyzer, the result for your low level QC is greater than +2s away from the mean. The result for the high level is just at the 2s from the mean. Per your laboratory's SOP, you rerun both controls. On the second run, both levels are greater than +2s away from the mean. The cuvettes and QC material are in date and do not appear visibly deteriorated. Which is the best response?
Recalibrate the instrument, and then rerun the controls
One of two controls that have been evaluated over the last 28 days gives a result on day 29 between 2 and 3 SDs of the mean; the other control is within 2 SDs of its mean. What is the correct procedure to follow?
Rerun the control and if acceptable continue with patients
coefficient variation
SD/mean x 100
reference range
The numeric range of test values for which the general population consistently shows similar results 95% of the time
The term R4S means that:
Two controls in the same run are greater than 4s units apart
Which of the following would be a valid indication for performing a bone marrow aspiration?
Unexpected pancytopenia
What stain is most commonly used for bone marrow aspirates?
Wright
How M:E determined normal value
all myeloid cells (not megakaryocytes) to all erythroids 2 and 4
A clinical laboratory scientist performs 30 replicate hemoglobin determinations on a single blood sample. When statistics are used to determine the precision of the method, the mean is 13.8 g/dL and 1 SD is 0.1 g/dL. This means that 95% of the results on this specimen lie:
between 13.6 and 14.0 g/d
smears/prep: bone marrow aspirates core biopsy
bone marrow aspirates = differential = coverslip smear w/ spicule core biopsy = imprint or in cases of dry tap = fat to cell ratio, overall cellularity
Red marrow children vs adults
children - all red marrow adults - concentrated to axial (end of long bons, hips, spine, rib cage, skull)
Bone marrow uses and specimens
core liquid marrow - spicules
Leukocyte Alkaline Phosphatase
elevated in leukamoid rxn decreased in CML
yellow marrow
fatty marrow reticulum cells histocytes extracellular matrix all other cells suspended
red marrow
hematopoietically active produces blood cells axial skeleton
evaluation of megakaryocytes process
low power, normal = mega/field
Nonspecific esterase
monocytic cells Monoblast= strong positive negative= myelocytic and lymphocytic cells
calibrator
purchased standard used to adjust an analyser
Myeloperoxidase
myeloblasts stains primarily neutrophilic granules myeloid precursors not present in lymphocytes AML vs ALL myeloblasts = strong positive monoblasts= faint positive lymph = negative
'dry tap'
no liquid marrow packed too tightly b/c does not contain liquid marrow not sufficient marrow
Preferred adult bone marrow site?
posterior or anterior iliac crest
Sudan Black B
stains phospholids, neutral fats, sterols, granulocytes phospholipids occur in primary and secondary granules Lymphocytes do not stain AML vs ALL myeloblast= strong positive monoblast= faint positive lymphocytes= negative Monocytes= variable
Bone marrow stain
wright or wright-giemsa