Chapter 34 - Spleen Flashcards
Where is the splenic v in relation to splenic a?
Posterior and inferior
Spleen is the largest producer of what antibody?
IgM
What % of the spleen is red pulp? Function?
85%; acts as filter for aged or damaged RBCs
What is pitting?
Removal of abnormalities in RBC membrane
What are Howell-Jolly bodies?
Nuclear remnants
What are Heinz bodies?
Hemoglobin
What is culling?
Removal of less deformable RBCs
What % of the spleen is white pulp? Function?
15%; immunologic function, contains lymphocytes and macrophages; major site of bacterial clearance that lacks preexisting abs; site of removal of poorly opsonized bacteria/debris
What is tuftsin?
An opsonin; facilitates phagocytosis (produced in spleen)
What is properidin?
Activates alternate complement pathway (produced in spleen)
When does hematopoiesis occur in the spleen?
Before birth and in conditions such as myeloid dysplasia
Where is the most common location of accessory spleen?
Splenic hilum (20%)
What is the most common nontraumatic condition requiring splenectomy?
ITP
What happens in ITP?
Antiplatelet IgG binds platelets, cause dec. platelet count –> gingival bleeding, petechiae, bruising, soft tissue ecchymosis
Treatment for ITP in children? Adults?
Children <10, usually resolves spontaneously; steroids (primary therapy), plasmapheresis, gammaglobulin for steroid-resistant disease, splenectomy for those who fail steroids
Why does splenectomy fix ITP?
Spleen is normal; removes IgG production and source of phagocytosis (80% respond)
TTP associated with what conditions?
Medial reactions, infections, inflammation, autoimmune disease
What happens in TTP?
Loss of platelet inhibition leads to thrombosis and infarction, profound thrombocytopenia; purpura, fever, AMS, renal dysfunction, hematuria, hemolytic anemia
Treatment for TTP?
Plasmapheresis (primary), steroids, ASA - 80% respond to medical therapy
Most common cause of death due to TTP?
Due to ICH or acute renal failure
Risk of postsplenectomy sepsis?
0.1%, increased risk in children; highest in pts with splenectomy due to hemolytic disorders or malignancy
Most common bacteria causing OPSS?
S. pneumonia, N. meningitidis, H. flu
Most episodes occur within what time frame?
2y post-splenectomy
Ideally how old should a child be before splenectomy?
5; allows Ab formation, child can get fully immunized
Vaccines needed before splenectomy?
Pneumococcus, meningococcus, H. flu
Postsplenectomy lab changes?
Increased RBCs, WBCs, platelets; if plt >1x10^6, need ASA
What is the #1 splenic tumor overall as well as the #1 benign splenic tumor? Treatment?
Hemangioma; splenectomy if symptomatic
What is the #1 malignant splenic tumor?
Non-Hodgkin’s lymphoma
When is operation indicated for splenic cyst?
If symptomatic or >10cm
Lab changes in hypersplenism?
Decreased platelets, WBCs, and RBCs
What is the definition of hypersplenism?
Dec. in circulating RBC, plts, or WBC AND normal compensatory hematopoietic response in bone marrow AND correction of cytopenia by splenectomy W/ or W/OUT splenomegaly
What is the most common cause of hypersplenism?
Secondary: increased venous pressure (portal HTN, CHF), malignant disease, chronic inflammatory disease, myeloproliferative disease, infectious, amyloidosis, AIDS, hemolytic anemias, polycythemia vera
Sarcoidosis of the spleen causes what?
Anemia, decreased platelets
What is Felty’s syndrome?
RA, hepatomegaly, splenomegaly
What is Gaucher’s disease?
Lipid metabolism disorder leading to splenomegaly
What is the most common congenital hemolytic anemia requiring splenectomy?
Spherocytosis
What is the defect in spherocytosis?
Spectrin deficit (membrane protein) causing deformed RBCs and splenic sequestration
What does spherocytosis lead to?
Pigmented stones, anemia, reticulocytosis, jaundice, splenomegaly
Treatment for spherocytosis?
Splenectomy and cholecystectomy
What is elliptocytosis?
Spectrin and protein 4.1 deficit (membrane protein); causes symptoms similar to spherocytosis
What does pyruvate kinase deficiency cause?
Results in congenital hemolytic anemia; altered glucose metabolism, RBC survival enhanced by splenectomy
What is the most common congenital hemolytic anemia NOT involving a membrane protein deficit?
Pyruvate kinase deficiency
What precipitates hemolysis with G6PD deficiency?
Infection, certain drugs, fava beans; splenectomy usually not required
Is splenectomy required for sickle cell anemia?
Spleen autoinfarcts, splenectomy NOT required
Use of splenectomy in beta thalassemia?
May decrease hemolysis and symptoms; most die in teens secondary to hemosiderosis
What cells are characteristic of Hodgkin’s disease?
Reed-Sternberg cells
How is Hodgkin’s disease staged?
Stage I: 1 area or 2 contiguous areas on same side of diaphragm; stage II: 2 noncontiguous areas on same side of diaphragm; stage III: involved on each side of diaphragm; stage IV: liver, bone, lung or any other nonlymphoid tissue except spleen
What are the different types of Hodgkin’s lymphoma? What has the best prognosis? Most common?
Lymphocyte predominant (best prognosis), lymphocyte depleted (worst prognosis), nodular sclerosing (most common)
What is the most common cause of chylous ascites?
Lymphoma
What % of non-Hodgkin’s lymphomas are B cell?
90%
Treatment for hairy cell leukemia?
Splenectomy, INF-gamma
What are the causes of spontaneous splenic rupture?
Mononucleosis, malaria, sepsis, sarcoid, leukemia, polycythemia vera
What is splenosis? Cause?
Splenic implants; usually related to trauma
When do you see Howell-Jolly bodies?
In hyposplenism
What is the most common cause of splenic artery or splenic vein thrombosis?
Pancreatitis
What patients get splenic artery aneurysms?
Females; secondary to fibromuscular dysplasia, atherosclerosis
What are pappenheimer bodies?
Iron deposits
