What are the key clinical findings in a 2-year-old boy likely suffering from ALL?

In a 2-year-old boy likely suffering from acute lymphoblastic leukemia (ALL), the presence of irritability and elevated white blood cell (WBC) count are key clinical findings that support this diagnosis.

Irritability can be a result of anemia, fatigue, or malaise commonly associated with ALL, owing to the bone marrow's compromised ability to produce healthy blood cells. The elevated WBC count is particularly significant in ALL; while the total white blood cell count may be high, the cells present are often immature and dysfunctional lymphoblasts rather than mature lymphocytes.

These findings are indicative of how leukemia can interfere with normal blood production, leading to not only the symptoms of irritability due to decreased overall health but also the characteristic peripheral blood abnormalities. The combination of such signs would lead healthcare providers to further investigate the possibility of ALL in this age group.

Other options do not reflect the primary hallmarks of ALL as distinctly as variable irritability and elevated WBC counts, which are more directly linked to the pathophysiology of the disease.