Question 1

At what age is it normal for bone marrow cellularity to be 80% to 90% (i.e., has very little fat)?

Accepted Answer

At birth, bone marrow has very little fat and cellularity is typically around 80% to 90%. As we age, the amount of fat in the bone marrow tends to increase, causing a decrease in cellularity. By the time we reach old age, the bone marrow may be less than 50% cellular.

Question 2

Why is the white count in a normal full-term newborn elevated shortly after birth?

Accepted Answer

An absolute increase in neutrophils occurs as a normal response to the stress of birth and exposure to bacteria in the environment.

Question 3

What is the most likely reason that the red blood cell (RBC) count remains elevated in a newborn for the first 2 weeks of life?

Accepted Answer

The elevated red blood cell count in newborns for the first 2 weeks of life is primarily due to partial anoxia (low oxygen levels) in utero, which stimulates the production of erythropoietin, leading to an increase in red blood cell production.

Question 4

A normal 3-month-old boy has a hemoglobin of 11.2 g/dL. Which of the following is true about his hemoglobin? It is:

Accepted Answer

At 3 months of age, a normal hemoglobin level is lower than that of an adult. Hemoglobin levels in infants start higher at birth, decrease over the first few months of life, and then gradually increase to reach adult levels later in childhood.

Question 5

Iron deficiency anemia in older adults is most often a result of:

Accepted Answer

Iron deficiency anemia in older adults is usually caused by chronic blood loss from the gastrointestinal tract. This can be due to things like ulcers, diverticulitis, or colonic polyps. Poor nutritional intake of iron or malabsorption of iron can contribute to iron deficiency anemia, but they are less common causes in older adults. The decreased ability to transport iron because of a decrease in transferrin is not a common cause of iron deficiency anemia in older adults.

Question 6

An 85-year-old woman has a hemoglobin of 10.5 g/dL. This is:

Accepted Answer

A hemoglobin level of 10.5 g/dL is considered low and falls below the normal range for both males and females. In an 85-year-old woman, this could be a sign of an underlying disease such as anemia or another condition that requires further evaluation by a healthcare provider. Choice A is incorrect because a hemoglobin level of 10.5 g/dL is not high. Choice B is incorrect because the normal range of hemoglobin levels can vary based on age and sex, and a hemoglobin level of 10.5 g/dL falls below the normal range for both male and female patients. Choice D is incorrect because myelophthisic anemia is a rare type of anemia caused by the replacement of bone marrow by abnormal cells, and there is no indication in the question stem that this is the cause of the patient's low hemoglobin level.

Question 7

What is the normal bone marrow cellularity in the population older than 65 years?

Accepted Answer

Bone marrow cellularity decreases in the older population and is approximately 30%.That of a young adult is 50%.This change may be caused by an increase in the volume of spongy tissue in the bone,as well as an increase in fat,rather than an actual decrease in hematopoietic tissue.

Question 8

Which of the following age groups normally has the lowest mean red cell values (red cell count, hemoglobin, hematocrit)?

Accepted Answer

Preterm premature infants are at risk for anemia of prematurity due to their underdeveloped erythropoietin production and shortened red cell lifespan. This results in low mean red cell values such as red cell count, hemoglobin, and hematocrit.

Question 9

A Complete blood count (CBC) is requested on a full-term newborn girl, and the following results are obtained:

What conclusion can be made regarding these data for this infant?

Accepted Answer

The answer of A Complete blood count (CBC) is requested...

Question 10

Why is there a relative lymphocytosis in a 2 year old?

Accepted Answer

Lymphocytes are a type of white blood cell involved in the immune response. In young children, the immune system is still developing and maturing, leading to an increased number of lymphocytes. This is why there is a relative lymphocytosis in a 2 year old. An absolute neutropenia (choice A) occurs when there is a decreased number of neutrophils, another type of white blood cell, in the blood. This is not relevant to the question. The proportion of marginated neutrophils (choice C) or lymphocytes (choice D) has no direct relation to the presence of a relative lymphocytosis, so they are not the best choice.

Question 11

Which of the following is most commonly seen in the population older than70 years?

Accepted Answer

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults, particularly in those older than 70 years, characterized by the accumulation of functionally incompetent lymphocytes.

Question 12

Which of the following is true concerning age-related changes of hemostasis in older adults?

Accepted Answer

Increased fibrinogen is a common age-related change in hemostasis among older adults. Aging is associated with a prothrombotic state, characterized by increased levels of certain coagulation factors, such as fibrinogen, rather than decreased platelet activity or increased fibrinolysis.

Question 13

All of the following are normal peripheral blood RBC findings at birth in a full-term infant except:

Accepted Answer

At birth, full-term infants typically have a higher mean cell volume (MCV), often greater than 90 fL, reflecting the presence of larger, more immature red blood cells. The other options (nucleated RBCs, reticulocytosis of 5%, and hemoglobin of 20.2 g/dL) are normal findings in newborns.

Question 14

Which of the following is more likely to result from poor absorption rather than inadequate nutritional intake in older adults?

Accepted Answer

Vitamin B12 deficiency in older adults is more commonly due to poor absorption rather than inadequate dietary intake. This is because as people age, they may develop conditions such as atrophic gastritis that reduce the stomach's ability to absorb vitamin B12.

Quiz 38: Pediatric and Geriatric Hematology

At what age is it normal for bone marrow cellularity to be 80% to 90% (i.e., has very little fat) ?