What are the major functions of the spleen?
Removal of elements in the blood:
-clearing blood cells and bacteria
-recycling iron and globins
Secondary lymphoid organ
-Ag capture and presentation to T/B cells
-normal during fetal development
-compensatory extramedullary site in adults
Stores formed elements:
-stores 30-40% of platelets
What effects can be seen as result of splenomegaly/hypersplenism?
-pressure/pain in LUQ
-risk of rupture
-anemia (sequestration of RBCs)
-leukopenia (sequestration of leukocytes)
-thrombocytopenia (sequestration of platelets, up to 80-90% of total)
What are common causes of splenomegaly?
-blood cell disorders (neoplasms and anemias)
-IEM (Gaucher, Neimann-Pick, etc.)
-cancer of the spleen/metastasis to the spleen
What are causes of congestive splenomegaly?
-cardiac decompensation/right heart failure
-obstruction of portal or splenic vein
What are causes of splenic infarcts?
Occlusion of splenic artery (lack of collateral blood supply):
-myeloproliferative disorders (MPD)
What are common effects of splenic infarcts?
-dramatic increased risk of infection by encapsulated bacteria (pneumococcus, H. influenzae, meningococcus)
What are the most common primary and secondary neoplasms of the spleen?
-rare; lymphagiomas and hemangioma
What conginital abnormalities of the spleen exist?
What is their significance if any?
-rare, typically associated with other abnormalities
-more common that aplasia
-splenectomy is used as treatment in immune thrombocytopenia and hereditary shperocytosis; if an accessory spleen is not removed, theraputic benefit is diminished
What are common causes of splenic rupture?
Trauma, especially to an acutely enlarged spleen
Uncommon in chronically enlarged spleens (fibrosis)
Especially in the setting of:
-neoplasms of the spleen
What are the effects of splenic rupture?
massive intraperitoneal hemorrhage resulting in death if not treated with emergent splenectomy
What are signs of splenic rupture?
Can present with:
-left shoulder pain (Kehr sign)
What is a possible post-splenectomy complication?
Overwhelming post-splenectomy infection (OPSI)
encapsulated bacteria are mainly eliminated by the spleen
- Streptococcus pneumoniae
- Neisseria meningitidis
- Haemophilus influenae B
- highest risk first 3 years following splenectomy