What is a normal spleen size in adults?

Normal Spleen Size in Adults

The normal spleen size in adults is ≤13 cm in vertical length when measured in the coronal plane on imaging studies. 1

Standardized Measurement Approach

Imaging is the gold standard for spleen size assessment, as physical examination alone is unreliable for detecting mild to moderate splenomegaly. 1 The measurement technique should follow these parameters:

• Measure the vertical length in the coronal plane as the greatest longitudinal distance from dome to tip. 1
• CT scan, ultrasound, or PET/CT can all be used for measurement, with CT measuring vertical length on coronal images. 1
• For transverse CT, multiply the number of spleen slices by slice thickness to obtain coronal length. 2
• PET/CT can measure splenic coronal diameter on maximum intensity projection images. 1

Size Classification Thresholds

The 13 cm threshold is established in the Lugano Classification and RECIL 2017 criteria and is widely applied across clinical contexts. 2 The grading system is:

• Normal: ≤13 cm 1
• Mild splenomegaly: 11-13 cm 1, 2
• Clinically significant splenomegaly: >13 cm 1, 2

Critical Clinical Considerations

Several important caveats exist when interpreting spleen size:

• Normal spleen size varies based on race, body size, and height, so the 13 cm cutoff should be interpreted with these factors in mind. 1
• A normal-sized spleen does not rule out splenic pathology—infiltrative processes like lymphoma can be present even with normal measurements. 1, 2
• Enlargement may result from non-pathological causes including variations in blood volume or use of hematopoietic growth factors. 1
• In cirrhotic patients, spleen size is critical for calculating the LSPS score (liver stiffness × spleen size/platelet count) to predict clinically significant portal hypertension. 3

Common Pitfalls to Avoid

• Do not rely on physical examination alone—imaging is necessary for accurate assessment, particularly in mild to moderate cases. 1
• Do not assume a normal-sized spleen excludes disease—always consider clinical context, as infiltrative processes may not cause enlargement. 1, 2
• Be aware that various medical conditions can affect spleen size without indicating primary splenic disease. 1