Imaging description
The left lobe of the liver can extend across the midline and hug the splenic capsule. When imaged on ultrasound, this can appear as a heterogeneously echogenic or hypoechoic mass surrounding the spleen. This can be mistaken for a perisplenic hemorrhage, subcapsular splenic hematoma, or mass [1].
Importance
The spleen is the most frequently injured solid organ in the abdomen. Frequently, focused assessment with sonography for trauma (FAST) is used, particularly in hemodynamically unstable patients, to rapidly assess for intraperitoneal and pericardial hemorrhage [2]. An elongated left hepatic lobe can be confused with subcapsular hematoma and potentially result in unnescessary laparotomy, further imaging, or tertiary care transfer (Figure 58.1).
Typical clinical scenario
An elongated left hepatic lobe can be an anatomic variant, most commonly in women, or it can be due to compensatory left lobe hypertrophy secondary to cirrhosis or right hepatic lobe atrophy or surgery [3].
Differential diagnosis
The differential diagnosis includes perisplenic hemorrhage or subcapsular splenic hematoma. Distinguishing an elongated left lobe of the liver is possible using ultrasound. Following the abnormality across the midline to the right upper quadrant will often show contiguity with the liver [1]. Color Doppler imaging over the region of interest should demonstrate the normal peripheral arterial and venous blood flow found in the liver parenchyma, separate from splenic flow [4].