34 Spleen Flashcards
anatomy and physiology: arterial supply
short gastrics and splenic artery (end arteries), also some from L gastroepiploic
anatomy and physiology: venous drainage
splenic vein is posterior and inferior to splenic artery … drains to portal vein
anatomy and physiology: spleen function
antigen processing center for macrophages, largest producer of IgM
anatomy and physiology: tissue composition
85% red pulp = filter for aged or damaged RBCs (pitting and culling) … 15% white pulp = immunologic function, contains lymphocytes and macrophages
anatomy and physiology: Howell-Jolly bodies
nuclear remnants, removed by spleen (red pulp)
anatomy and physiology: Heinz bodies
Hb, removed by spleen (red pulp)
anatomy and physiology: describe function of red pulp
filter for aged or damaged TBCs … culling = removal of less deformable RBCs …. pitting = removal of abnormalities in RBC membrane (Howell-Jolly bodies = nuclear remnants, Heinz bodies = Hb)
anatomy and physiology: describe function of white pulp
immunologic unction, contains lymphocytes and macrophages, major site of bacterial clearance that lacks preexisting antibodies, site of removal of poorly opsonized bacteria/particles/cellular debris, antigen processing occurs with interactions between macrophages and help T cells
anatomy and physiology: tuftsin
opsonin, facilitates phagocytosis, produced in spleen
anatomy and physiology: poperdin
activates alternate complement pathway, produced in spleen
anatomy and physiology: hematopoiesis
occurs in spleen before birth and in conditions such as myeloid dysplasia
anatomy and physiology: plt
spleen is reservoir
anatomy and physiology: accessory spleen
20%, MC found at splenic hilum
MC condition requiring splenectomy
ITP is the MC nontraumatic condition
indications for splenectomy
trauma, ITP, TTP (ITP much more common than TTP, ITP is MC non traumatic indication for splenectomy)
ITP: causes
drugs, viruses, etc
ITP: pathophys
anti-plt IgG –> bind plt –> decreased plt
ITP: px
petechiae, gingival bleeding, bruising, soft tissue ecchymosis
ITP: spleen abnl
spleen is normal
ITP: natural hx in kids
usually resolves spontaneously in kids <10 … AVOID splenectomy!
ITP: tx
steroids (primary therapy), gammaglobulin if steroid resistant, splenectomy indicated for those who fail steroids - removed IgG production and source of phagocytosis (80% respond after splenectomy), give platelets 1 hour preop
TTP: aka
thrombotic thrombocytopenic purpura
TTP: assoc with what?
medical reactions, infections, inflammation, autoimmune disease
TTP: pathophys
loss of plt inhibition —> thrombosis and infarction, profound thrombocytopenia
TTP: px
purpura, fever, mental status changes, renal dysfunction, hematuria, hemolytic anemia
TTP: response to tx
80% response to medical therapy
TTP: tx
plasmapheresis (primary), immunosuppression … splenectomy rarely indicated
TTP: mortality
death MC 2/2 intracerebral hemorrhage or acute renal failure
post-splenectomy sepsis syndrome: occurrence rate
0.1% after splenectomy, inc risk in kids
post-splenectomy sepsis syndrome: MC causes
strep pneumonia #1, H influenza, N meningitides
post-splenectomy sepsis syndrome: pathophys
specific lack of immunity (immunoglobulin IgM) to capsulated bacteria
post-splenectomy sepsis syndrome: highest risk patients
splenectomy for hemolytic disorders or malignancy
post-splenectomy sepsis syndrome: mortality risk
kids have inc risk of mortality after developing PSSS
post-splenectomy sepsis syndrome: mgmt. in kids
wait until at least 5yo before doing splenectomy b/c allows for Ab formation, child can get fully immunized
post-splenectomy sepsis syndrome: when does this occur?
usually within 2 years of splenectomy
post-splenectomy sepsis syndrome: post op mgmt. in kdis
kids <10yo should get ppx abx for 6 months (controversial)
post-splenectomy sepsis syndrome: vaccines
BEFORE splenectomy give pneumococcus, meningococcus, H flu
definition of hypersplenism
dec in circulating cell count of erythrocytes a/oplt a/o leukocytes AND normal compensatory heatopoietic responses present in bone marrow AND correction of cytopenia by splenectomy WITH OR WITHOUT splenomegaly
hemolytic anemias: list
membrane protein defects = spherocytosis, elliptocytosis … non-membrane protein defects = pyruvate kinase deficiency, G6PD deficiency, warm Ab-type acquired immune hemolytic anemia, sickle cell, beta thal
hemolytic anemias: MC congenital type that leads to splenectomy
overall = spherocytosis …. non-membrane protein defect = pyruvate kinase deficiency
hemolytic anemias: spherocytosis - describe, pathophys, result, mgmt
membrane protein deficit …. MC congenital hemolytic anemia requiring splenectomy … spectrin deficit (membrane protein) - deforms RBCs and leads to splenic sequestration (hypersplenism) … causes pigmented stones, anemia, reticulocytosis, jaundice, splenomegaly …. tx = splenectomy (curative) and cholecystectomy (ideal to wait until >5yo before splenectomy, give immunizations first)
hemolytic anemias: elliptocytosis - pathophys, px
membrane protein deficit …. sx and mech similar to - spherocytosis, but elliptocytosis is less common …. spectrin AND PROTEIN 4.1 deficit - deforms RBCs and leads to splenic sequestration (hypersplenism) … causes pigmented stones, anemia, reticulocytosis, jaundice, splenomegaly
pyruvate kinase deficiency - epi, describe, pathophys
hemolytic anemia 2/2 non-membrane protein defect …. results in congenital hemolytic anemia … MC of this subtype of hemolytic anemia to result in splenectomy …. causes altered glucose metabolism, RBC survival is enhanced by splenectomy
G6PD deficiency - describe
hemolytic anemia 2/2 non-membrane protein defect …. precipitated by infection, certain drugs, fava beans … splenectomy usually NOT needed
warm Ab-type acquired immune hemolytic anemia
hemolytic anemia 2/2 non-membrane protein defect …. indication for splenectomy
sickle cell anemia - pathophys
hemolytic anemia 2/2 non-membrane protein defect …. HbgA replaced with HgbS —> spleen usually auto-infarcts and splenectomy NOT required
beta thalassemia - pathophys, sx, mgmt., natural hx, tx
MC thalassemia …. 2/2 persistent HbgF, major = btoh chain affected, minor = 1 chain affected and a-sx …. sx = pallor, retarded body growth, head enlargement …. most pts die in teens 2/2 hemosiderosis … tx = medical - blood transfusions and iron chelators (deferoxamine, deferiprone), splenectomy (if pt has splenomegaly) may decrease hemolysis and sx
Reed-Sternberg cells vs Howell-Jolly bodies
Hodgkin’s disease (fried eggs) vs hyposplenism (dark spot on RBC)
Hodgkin’s disease: types
A - a-sx …. B - night sweats, fever, weight loss, unfavorable prognosis
Hodgkin’s disease: stages
1 = 1 area or 2 contiguous areas on the same side of the diaphragm …. 2 = 2 non-contiguous areas on the same side of the diaphragm …. 3 = incolced on each side of diaphragm … 4 = liver, bone, lung, or any other non-lymphoid tissue except spleen
Hodgkin’s disease: MC type
nodular sclerosing
Hodgkin’s disease: prognosis
lymphocyte predominant = best prognosis vs lymphocyte depleted = worse prognosis
Hodgkin’s disease: cells seen
Reed-Sternberg cells
Hodgkin’s disease: tx
chemo
Hodgkin’s disease: MCC of chylous ascites
lymphoma
non-Hodgkin’s lymphoma: prognosis, MC type, dx, tx
worse than Hodgkin’s …. 90% B cell lymphoma …. usually systemic disease by the time the diagnosis is made …. tx w chemo
hairy cell leukemia - tx
rarely need splenectomy
spontaneous spleen rupture - occurs in what conditions?
mononucleosis, malaria, sepsis, sarcoid, leukemia, polycythemia vera
splenosis
splenic implants, usually related to trauma
hyposplenism
see Howell-Jolly bodies
MC cause od splenic artery or splenic vein thrombosis
pancreatitis
postsplenectomy changes
inc RBCs, inc WBCs, inc plts (if plt >1x10^6 then give ASA)
MC splenic tumor - overall, benign, malignant
hemangioma is MC overall and benign … NHL is MC malignant
splenic hemangioma mgmt
tx w splenectomy IF sx … (remember it is MC splenic tumor - overall and benign)
NHL epi
MC malignant splenic tumor
mgmt. of splenic cysts
surgery if sx or >10cm
sarcoidosis of spleen - px and tx
anemia, dec plt …. tx = splenectomy for sx splenomegaly
felty’s syndrome - describe, tx
rheumatoid arthritis, hepatomegaly, splenomegaly … tx = splenectomy for sx splenomegaly
splenic abscess tx
usually splenectomy (bleeding risk w perc drainage)
echinococcal splenic cyst tx
splenectomy
results of splenectomy/hyposplenic condition - erythtocytes, plt, leukocytes
erythrocytes = howell-jolly bodies (nuclear fragments, dark purple spot on RBC), Heinz bodies (Hb deposits, dark blue spot on RBC), pappenheimer bodies (Fe deposits, lots of dark speckles), target cells, spur cells (acanthocytes) …. plt = transient thrombocytosis …. leukocytes = transient leukocytosis, persistent lymphocytosis, persistent monocytosis
guildelines for prevention of postsplenic sepsis
(1) vaccinate with polyvalent pneumococcal vaccine at least 10-14 days BEFORE splenectomy if possible …. () if urgent splenectomy, wait at least 14 days postprocedure to vaccinate … (3) for high risk pts (immunosuppressed, kids <10yo), give meningococcal vaccine and H flu vaccine …. (4) abx ppx for kids <5yo …. (5) early abx tx for initial signs of infection …. (6) MedicAlert bracelet
