Spleen Size Is Significantly Influenced by Body Height and Sex: Establishment of Normal Values for Spleen Size at US with a Cohort of 1200 Healthy Individuals.

PURPOSE: To define height- and sex-corrected normal values for spleen length and volume determined with ultrasonography (US).

MATERIALS AND METHODS: The authors performed a retrospective data review of stem cell donors who had provided written informed consent for stem cell donation and use of anonymized data and biologic materials for scientific and quality control purposes. Spleen length, spleen volume, and anthrophometric data were correlated in 1230 healthy volunteers to identify variables that affect spleen size. Multiple linear regression analysis was performed to weight effects of various variables on spleen size. Linear regression through the 95th percentile for men and women of different height cohorts generated the formula for the upper limit of normal for spleen length and volume. For validation, the upper limit of normal was calculated for each volunteer and compared with the observed value. Formulae to calculate the additional percentiles were similarly generated and validated. A cohort of 75 volunteers was analyzed twice to assess the stability of spleen length and volume over time.

RESULTS: Spleen length and volume were significantly and independently associated with sex (length: P < .001; volume: P = .012), body height (P < .001 for both), and weight (P < .001 for both), with men and taller and heavier individuals having longer and larger spleens. The spleen length of 20 of 324 women (6%) and 234 of 906 men (26%) exceeded the previously reported upper limit of normal of 12 cm. Repeat measurements indicated that spleen length (median difference, 0.10 cm; range, -1.8 to 1.7 cm) and volume (median difference, 3 cm(3); range, -106 to 142 cm(3)) were quite stable. A mobile application that performs these calculations is available for download.

CONCLUSION: The authors define height- and sex-corrected normal values for spleen length and volume for women with a body height of 155-179 cm and men with a body height of 165-199 cm and propose validated algorithms to gauge the percentile of an individual's spleen size.