Last revised by Mohammad Taghi Niknejad on 25 Dec 2023

The spleen is an organ of the hematological system and has a role in immune response, storage of red blood cells and hematopoiesis.

The spleen is a wedge-shaped organ lying mainly in the left upper quadrant (left hypochondrium and partly in the epigastrium) and is protected by the left 9th to 11th ribs. It is soft, highly vascular and dark purple in color.

Size and weight vary from person to person but on average, the spleen is around 2.5 cm thick, 7.5 cm broad and 12 cm in length. Its volume is on average between 100 to 300 cm 3,12. For pediatric measurements, see the article spleen size (pediatric)

The spleen has two poles (superior and inferior), three borders (superior, inferior and intermediate) and two surfaces (diaphragmatic and visceral). It is enclosed by a thin capsule, which is easily ruptured. 

The diaphragmatic surface contains impressions from the 9th to 11th ribs. The visceral surface has three impressions - these are the gastric area for the stomach, the colic area for the splenic flexure of the colon and the renal area for the left kidney.

The spleen is completely covered by peritoneum, except at the hilum, which forms a number of ligaments 6,7:

  • diaphragmatic surface (superoposteriorly): dome of the left hemidiaphragm, left 9th to 11th ribs

  • visceral surface 

    • pancreatic tail - medial 

    • left kidney and adrenal gland - posteromedial 17

    • greater curvature and fundus of stomach - anteromedial 17

    • splenic flexure of the transverse colon - inferior

A normal spleen may indent the cardia of the stomach. The fundus of the stomach may be indented by spleneculi or ectopic spleen 15,16.

  • from splenic hilar lymph nodes to pancreaticosplenic lymph nodes, then draining to celiac lymph nodes

  • best assessed in the supine, right lateral position with the left arm placed behind the head

  • visualized best obliquely in the 9th or 10th intercostal spaces

  • echogenicity usually higher when compared to the liver, but may be iso- or hypoechoic

The splenic parenchyma should be assessed in the portal venous phase as inhomogeneous splenic enhancement (zebra or psychedelic spleen) seen in the arterial phase can mimic a splenic laceration or contusion 5.

Embryologically, the spleen forms from several splenic buds that fuse together within the dorsal mesentery of the foregut (dorsal mesogastrium) 10.

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.