Normal Spleen Size in Adults

Standardized Measurement Technique

The normal spleen size in adults is defined as a vertical length of 13 cm or less when measured in the coronal plane, according to the American College of Radiology and the European Society for Medical Oncology 1, 2, 3
Spleen size should be measured in the coronal plane as a vertical length, as recommended by the American College of Radiology 2, 3
Measurement can be performed using CT scan, ultrasound, or alternative calculation, with CT scan measuring the vertical length in the coronal image, as suggested by the European Society for Medical Oncology 2
PET/CT can also be used to measure splenic coronal diameter on a PET maximum intensity projection image, as recommended by the Society of Nuclear Medicine and Molecular Imaging 3

Length: ≤13 cm is considered normal, according to the American College of Radiology and the European Society for Medical Oncology 1, 2

A spleen measuring 11-13 cm in length is considered mild splenomegaly, as defined by the American College of Radiology 4
Splenomegaly >13 cm is considered clinically significant, according to the American College of Radiology and the European Society for Medical Oncology 1, 4
In lymphoma staging and assessment, splenomegaly is defined as >13 cm in vertical length, as recommended by the National Comprehensive Cancer Network and the European Society for Medical Oncology 1, 5

Normal spleen size can vary based on race, body size, and height, as noted by the American College of Radiology 1
A spleen may be normal in size but still contain pathology (e.g., lymphoma), as cautioned by the American College of Radiology and the European Society for Medical Oncology 1
Enlargement may be due to non-pathological causes such as variations in blood volume or use of hematopoietic growth factors, as explained by the American Society of Hematology and the European Society for Medical Oncology 5
When evaluating spleen size in clinical practice, imaging is more reliable than physical examination, as recommended by the American College of Radiology and the Society of Nuclear Medicine and Molecular Imaging 6

Physical examination alone is unreliable for detecting mild to moderate splenomegaly, as noted by the American College of Radiology and the European Society for Medical Oncology 6
A normal-sized spleen does not rule out splenic pathology, as cautioned by the American College of Radiology and the European Society for Medical Oncology 1, 5
Various medical conditions can affect spleen size without indicating primary splenic disease, as explained by the American College of Radiology and the European Society for Medical Oncology 1