Identifying threshold sizes for enlarged abdominal lymph nodes in different age ranges from about 200,000 individual’s data

The threshold size for enlarged abdominal lymph nodes (E-ALNs), a common pediatric disorder, has yet to be standardized. According to the maximum short-axis diameter, this study divided ALNs into Grade A (≥ 10 mm), Grade B (8–10 mm), Grade C (5–8 mm), and Grade D (< 5 mm, normal). To identify the threshold size for E-ALNs, the prevalence of each grade was compared between asymptomatic individuals and symptomatic (e.g., abdominal pain) individuals without other diseases (e.g., appendicitis) that could explain the symptoms for different ages using data from > 200,000 individuals. The results showed the following: (1) For ages 1–3 years, the recommended threshold size is 8 mm, as the differences in the prevalence between the two groups were nonsignificant for Grade C but significant (p < 0.05) for both Grades A and B. (2) For ages 3–14 years, the recommended threshold size is 5 mm, as the differences between the two groups were significant (p < 0.05) for Grades A, B, and C. (3) The prevalence of Grades A, B, and C was very low for ages 0–1 years and high for ages 1–6 years. (4) The prevalence for males was generally higher than that for females for Grades A and B.