Answer :
Final answer:
In a 3-year-old girl with a history of constipation and knee pain being evaluated for potential lead poisoning, one would expect to see basophilic stippling on the peripheral blood smear.
Explanation:
The clinical scenario describes a 3-year-old girl presenting with a limp and knee pain, which are non-specific symptoms that could be associated with a range of conditions, including infection, trauma, inflammatory conditions, or possibly an underlying hematological condition such as a blood disorder. Given the context of the history of constipation and that the question suggests examining a peripheral blood smear, one relevant condition to consider would be lead poisoning, which can present with gastrointestinal symptoms (like constipation) and can cause a limp or joint pain due to its effects on the bones and joints. Lead poisoning is known to produce characteristic findings on a peripheral blood smear, specifically basophilic stippling of red blood cells.
Furthermore, the inclusion of other options like Heinz bodies, hypersegmented neutrophils, and schistocytes suggest that the answer is not about the other conditions associated with these findings. Heinz bodies are seen with oxidative damage to red blood cells as in G6PD deficiency; hypersegmented neutrophils are a hallmark of megaloblastic anemias; and schistocytes are associated with mechanical hemolysis, as seen in conditions like disseminated intravascular coagulation (DIC) or thrombotic thrombocytopenic purpura (TTP). Based on the information given and common pediatric clinical scenarios, basophilic stippling would be the expected finding on the blood smear of a child with symptoms possibly indicative of lead poisoning.
