Palpation is a fundamental technique in the physical examination used to feel the size, texture, and location of organs. The primary application of this technique to the upper abdomen is to determine if the spleen is enlarged, a condition known as splenomegaly. This physical assessment provides an initial indication of potential underlying health issues.
The Spleen’s Normal State and Location
The spleen is located deep within the left upper quadrant (LUQ) of the abdomen, lying under the diaphragm and protected by the ninth through eleventh ribs. In a healthy adult, the spleen is roughly the size of a fist. Due to this protected position high up beneath the rib cage, the spleen is generally not palpable during a routine physical examination.
This highly vascular organ serves as the body’s primary blood filter. It is responsible for recycling old or damaged red blood cells and plays a significant role in immune surveillance, helping to defend the body against pathogens.
Clinical Reasons for Spleen Palpation
The physical examination for splenomegaly is indicated when a patient presents with signs or symptoms suggesting an underlying condition is causing the spleen to swell. A palpable spleen below the left costal margin is considered an abnormal finding, prompting further investigation. The organ can enlarge due to various pathophysiological mechanisms, often classified as congestive, infiltrative, immune, or neoplastic processes.
Infectious diseases frequently cause splenomegaly as the organ works to filter and combat pathogens. Examples include viral infections like infectious mononucleosis, bacterial infections such as endocarditis, or parasitic diseases like malaria. Blood disorders and hematologic malignancies, including leukemias, lymphomas, or hemolytic anemias, also lead to enlargement where the spleen’s workload is dramatically increased.
Conditions that increase pressure in the veins supplying the liver, such as portal hypertension often caused by cirrhosis, result in blood backing up and pooling in the spleen. This congestive mechanism causes the organ to swell considerably.
Step-by-Step Palpation Techniques
To begin the examination, the patient should be positioned lying flat on their back, known as the supine position, with their knees slightly bent. This positioning helps to relax the abdominal muscles, making the area more accessible for the examiner. The examiner typically stands on the patient’s right side to perform the palpation.
The most common method is the bimanual technique. The examiner places their left hand underneath the patient’s lower left rib cage to provide support and gently push the spleen forward. The right hand is then placed flat on the abdomen, beginning well below the left costal margin. Palpation starts low because an extremely enlarged spleen can extend far down into the abdomen.
The examiner presses gently inward and upward with the right hand, asking the patient to take a deep breath. Deep inhalation causes the diaphragm to push the spleen downward, bringing its edge into contact with the examiner’s fingertips if it is enlarged. The examiner should feel for the splenic tip to “bump” the fingers during peak inspiration. If the spleen is not felt, the patient may be repositioned onto their right side, known as the right lateral decubitus position, which uses gravity to shift the spleen more anteriorly and inferiorly.
An alternative approach is the hooking technique, where the examiner stands on the patient’s left side and “hooks” their fingers under the left costal margin, again instructing the patient to inhale deeply. Across all techniques, the examiner must use light pressure, as overly aggressive palpation can be dangerous, especially in cases of fragile enlargement. The goal is to let the spleen descend and gently meet the fingertips, rather than forcefully pressing to find it.
Interpreting the Findings
A palpable spleen indicates splenomegaly, meaning the organ has become enlarged. The finding is considered abnormal if the splenic edge is felt more than 2 centimeters below the left costal margin. Clinicians use a grading system to quantify the degree of enlargement, measuring the distance the spleen extends below the costal margin in centimeters.
Mild splenomegaly is defined as an extension less than 5 centimeters below the costal margin. Moderate enlargement is considered to be between 5 and 10 centimeters below the margin, while massive splenomegaly is an extension greater than 10 centimeters or one that crosses the midline of the abdomen.
Following palpation, the positive finding of an enlarged spleen is usually confirmed and precisely measured using non-invasive imaging, most commonly an abdominal ultrasound. Imaging provides a more accurate measurement of the spleen’s craniocaudal length or volume, which helps to track the progression or regression of the underlying disease.