Question 143
A 63-year-old male with a past medical history of well-controlled hypertension reports to his family physician that over the past 6 months he has had increasing fatigue, weakness, a lack of appetite with a resultant 10 lb. weight loss, and a generalized malaise. A complete blood cell count reveals:
Hemoglobin: 12.2 g/dL
Hematocrit: 36%
White blood cell count: 45 x 103 cells/mm3
Platelet count: 600,000/mm3
The doctor suspects a chronic leukemia, but would like to rule out a leukemoid reaction caused by a smoldering infection. Which of the following laboratory tests would best assist in this distinction?
A. Serum protein electrophoresis
B. Lactate dehydrogenase
C. Leukocyte alkaline phosphatase
D. Repeat the white blood cell count
E. Alanine aminotransferase
Answer for Question 143
Answer: C (Leukocyte alkaline phosphatase)
Explanation: In a leukemoid reaction, the white blood cell count can be markedly elevated, and 45,000 cells/mm3 would be easily possible. In a leukemoid reaction, the white blood cells are functioning normally and an increased amount of leukocyte alkaline phosphatase would be expected; however, in CML the leukocyte alkaline phosphatase is commonly low.
Question 144
A 61-year-old male with a past medical history of well-controlled hypertension and hyperlipidemia reports to his family physician that over the past 12 months he has had increasing fatigue, weakness, and a lack of appetite with a resultant 20 lb. weight loss. A complete blood cell count reveals:
Hemoglobin: 11.8 g/dL
Hematocrit: 38%
White blood cell count: 52 x 103 cells/mm3
Platelet count: 560,000/mm3
Physical examination reveals mild splenomegaly. A peripheral smear would reveal which of the following?
A. An increased number of mature and maturing granulocytes
B. Blasts with a minimal amount of cytoplasm
C. Blasts with a prominent amount of cytoplasm
D. Numerous plasma cells
E. Schistocytes
F. Bite cells
G. Red blood cells with parasites
Answer for Question 144
Answer: A (An increased number of mature and maturing granulocytes)
Explanation: The clinical scenario (an older male) presenting over time with a disease process, with an elevated white blood cell count, elevated platelet count, and mild anemia, and with splenomegaly on the physical examination is consistent with a chronic leukemia. An increased number of mature and maturing granulocytes is consistent with chronic myeloid leukemia. Blasts would be consistent with an acute leukemia, which would present over the course of days to weeks. Numerous plasma cells could indicate multiple myeloma; however, these patients often present with bone pain or signs/symptoms related to hypercalcemia or renal disease.
Question 145
A pathologist is reviewing a blood smear. Numerous red blood cells on the slide have a single peripheral extension from the edge of the cell. Of the following, what is the most likely diagnosis for the patient?
A. Cirrhosis of the liver
B. End-stage kidney disease
C. Myelofibrosis
D. Disseminated intravascular coagulation
E. Hereditary spherocytosis
Answer for Question 145
Answer: C (Myelofibrosis)
Explanation: Red blood cells with a single peripheral extension from the edge of the cell are tear drop cells (i.e., dacrocyte). Tear drop cells are most commonly associated with bone marrow fibrosis. Both burr cells and spur cells (i.e., acanthocytes) have extensions from the periphery of the cell, but the extensions are numerous. Burr cells have regularly distributed extensions and are seen most commonly as artifact; however, they also occur in liver disease and uremia. Spur cells have numerous extensions but they are irregularly distributed. Spur cells are seen in liver disease, abetalipoproteinemia, and McLeod syndrome. Schistocytes have extensions of at least two ends (or, at least two ends of the cell are pointed) and are fragmented. They are associated with DIC. In hereditary spherocytosis, the red blood cells are smaller and contracted with no central pallor.