PROFICIENCY TESTING SERVICE AMERICAN ASSOCIATION OF BIOANALYSTS 205 West Levee St.  Brownsville, TX 78520-5596 800-234-5315  956-546-5315  Fax 956-542-4041

PARTICIPANT STATISTICS PERIPHERAL BLOOD SMEAR FIRST QUADRIMESTER 2010

Specimen 1Specimen 2 MANUAL DIFFERENTIAL Mean SDRange% Mean SD Range% Basophils %0.11.0 0 ‐ 80.11.0 0 ‐ 8 Eosinophils %5.72.54 ‐ 12 0.1 1.0 0 ‐ 8 PMN (Bands/Segs)% 55.4 3.3 45 ‐ 65 40.0 1.4 36 ‐ 44 Lymphocytes % 33.7 4.0 21 ‐ 46 46.9 6.0 13 ‐ 52 Monocytes %0.94.10 ‐ 12 8.2 3.4 0 ‐ 19 Abnormal/Other %3.46.20 ‐ 22 12.8 9.4 0 ‐ 41

Question/Response Specimen 1Specimen 2 Yes/True 47 8 ***** No/False 20 59 TOTAL POPULATION 67 67

Correct responses are defined as those reflecting agreement among 80% or more of all participants or referees. Unacceptable responses are indicated by "*****" on the Flagging line of each specimen.

1Q2010 Periperhal Blood Smear Page 1 of 3 Peripheral Blood Smear ‐ Slide 1

*To see the original fullsized immages, please refer to the original CD or sign on to your data entry sheet at http://www.aab‐pts.org/

Specimen 10Q1‐1: A 26‐year‐old woman is being evaluated for an irregular menstrual cycle. CBC results are as follows: WBC 8.6, Hgb 12.8 g/dL, Hct 38.4%, Plts 220,000/µL. You are to perform a manual differential, based on the indicated cells. Would you report your differential or refer the slide for a pathologist’s review?

The automated CBC values do not indicate any significant abnormalities in the RBC, WBC, or platelet counts. Review of the peripheral smear of this patient shows no significant or , and no inclusions are evident. There are no morphologic abnormalities of white blood cells and they are present in the expected distribution. In short, this is a “normal” peripheral blood smear and the findings correlate quite well with the automated CBC values. Unless it is the practice in your facility to refer all peripheral smears to a pathologist for review, the differential for this sample could be reported as is. However, 70% of the respondents said they would report the differential, while the other 30% said they would not, implying that the peripheral smear would be sent for pathology review. This disparity in answers may be the result of poor wording of the question! In other words, a YES answer could mean, “Yes, I would report the differential,” or “Yes, I would refer the slide for a pathologist’s review.” The question should more appropriately have been worded, “Would you refer the slide for a pathologist’s review?”

1Q2010 Periperhal Blood Smear Page 2 of 3 Peripheral Blood Smear ‐ Slide 2

*To see the original fullsized immages, please refer to the original CD or sign on to your data entry sheet at http://www.aab‐pts.org/

Specimen 10Q1‐2: A healthy 12‐year‐old girl is seen for a pre‐camp physical. CBC results are as follows: WBC 7.7, Hgb 13.1 g/dL, Hct 39.4%, Plts 198,000/µL. You are to perform a manual differential, based on the indicated cells. Since the red cell indices from the CBC show a normocytic, normochromic population, would you report this peripheral smear as unremarkable?

As with Specimen #1, the automated CBC values do not indicate any significant abnormalities in the red cell, white cell, or platelet counts. Looking at the peripheral smear, the white blood cells show no morphologic abnormalities and the differential count is within expected ranges. However, the same is not true for the red blood cells. There is anisocytosis and poikilocytosis due to the presence of elliptocytes (sometimes referred to as “pencil cells” or “cigar cells” in older literature). Elliptocytes are elongated red cells where the length of the cell is longer than twice the width. The term “ovalocyte” is often used interchangeably with elliptocyte, although some strict morphologists maintain that the ovalocyte is not quite as slender as the elliptocyte.

Elliptocytes are quite numerous on this patient’s peripheral smear. It is likely that she has hereditary elliptocytosis (HE), an inherited abnormality of the red cell cytoskeleton. Typically, at least 25% of the red cells are elliptocytes, although the number may be much higher. It affects about 1 in 5000 individuals and is inherited as an autosomal dominant trait. The majority of patients with HE are completely asymptomatic and, due to a compensated hemolysis, have normal hemoglobin values and red cell indices. The diagnosis is made incidentally when a routine blood smear is examined, much like we see in this patient. However, about 5‐10% of individuals with HE suffer from moderate to severe hemolysis. Small numbers of elliptocytes (usually <25%) may be seen in individuals with iron deficiency anemia, certain types of , , and myelofibrosis and myelodysplastic syndromes, among others.

At a minimum, the elliptocytosis seen with this case should be documented on your report to the patient’s physician. Depending upon your laboratory, it may also be flagged for review by your pathologist.

1Q2010 Periperhal Blood Smear Page 3 of 3