57 Hypersplenism and Hyposplenism Flashcards
Defined as blood cytopenias in the setting of splenomegaly
Hypersplenism
Accompanied by hyperplasia of the affected cell precursors in the marrow
TRUE OR FALSE
The blood cytopenias are generally corrected by relief of portal hypertension.
FALSE
The blood cytopenias are not generally corrected by relief of portal hypertension.
The embryonic spleen appears in the __________of gestation as a multiply lobulated condensation of highly vascular mesenchymal cell aggregates interposed in the arterial circulation in the dorsal mesogastrium.
First trimester
Genes are essential for spleen formation, and defects in their expression result in hyposplenia or asplenia
HOX11 and WT1 genes
The lymphoid compartment, the white pulp, begins its development early in the __________of gestation, when mature T cells, principally ________ lymphocytes, form a continuous layer along the length of the vessels (periarteriolar sheaths).
Second trimester
CD4+ lymphocytes
CD8+ cells reside in_______________ and a specialized subset of γδT cells home to the_________
Splenic cords
Pulp
Immunoglobulin (Ig) D+ and IgG+ B lymphocytes form localized deposits, the (primary or secondary) lymph follicles.
Primary lymph follicles
(Primary or Secondary) follicles arise later in life, after exposure to immunologic stimuli, and have a distinctive structure that includes a germinal center, a mantle zone, and a marginal zone containing IgM+ and IgG+ B lymphocytes.
Secondary follicles
The normal adult spleen weighs _______and has a blood flow that is approximately ____% of the cardiac output.
135 ± 30 g
5%
The spleen is composed of (3 components)
- White pulp
- Marginal zone
- Red pulp
Approximately__________ of platelets are normally sequestered in the spleen
One-third
TRUE OR FALSE
The red pulp plays a major role in adaptive immunity.
FALSE
The white pulp plays a major role in adaptive immunity.
The spleen is involved in the phagocytosis of encapsulated bacteria, including:
- Streptococcus pneumoniae
- Haemophilus influenzae
- Neisseria meningitidis
The benefits of splenectomy in immune thrombocytopenia is a result of :
- Decreased production of antiplatelet antibodies
- Decreased clearance by macrophages of antibody-coated platelets through the Fc recognition function of its large macrophage population
Spleen enlargement may result from:
- Expansion of the red pulp compartment with increased blood flow
- Extramedullary hematopoiesis, notable in primary myelofibrosis
- Hyperplasia or neoplasia involving the white pulp, such as in infectious mononucleosis or lymphoma; or histiophagocytic hyperplasia
The increased size of the filtering bed is more pronounced when the splenomegaly is caused by congestion as in _____________ than when it is caused by cellular infiltration as in leukemias, extramedullary hematopoiesis, or amyloidosis.
Portal hypertension
TRUE OR FALSE
Sequestered white cells and platelets survive in the spleen and may be available when increased demand requires neutrophils or platelets, although their release may be slow.
TRUE
Sequestered white cells and platelets survive in the spleen and may be available when increased demand requires neutrophils or platelets, although their release may be slow.
Causes of Massive Splenomegaly
- Myeloproliferative disorders
a. Primary myelofibrosis
b. Chronic myeloid leukemia - Lymphomas
a. Hairy cell leukemia
b. Chronic lymphocytic leukemia (especially
prolymphocytic variant) - Infectious
a. Malaria
b. Leishmaniasis (kala azar) - Extramedullary hematopoiesis
a. Thalassemia major - Infiltrative
a. Gaucher disease
TRUE OR FALSE
Slight to moderate enlargement of the spleen usually does not produce local symptoms.
TRUE
Slight to moderate enlargement of the spleen usually does not produce local symptoms.
Even massive splenomegaly can be well tolerated if it develops gradually.
Splenic rupture is uncommon but can occur spontaneously with most causes of:
Splenic enlargement or after blunt trauma
TRUE OR FALSE
Generally, a palpable spleen signifies splenomegaly and is measured by the number of centimeters the spleen extends below the left costal margin.
TRUE
Generally, a palpable spleen signifies splenomegaly and is measured by the number of centimeters the spleen extends below the left costal margin.
Splenic size is most accurately measured with
Abdominal ultrasound or computed tomographic scans
Imaging used primarily to identify cysts, abscesses, and infarcts
Magnetic resonance imaging
A wandering spleen
An uncommon phenomenon in which the spleen hangs by a long pedicle of mesentery
Splenoptosis
Splenoptosis may present in three ways:
(a) an asymptomatic mass in the pelvis;
(b) intermittent abdominal pain with or without gastrointestinal symptoms; or less often,
(c) an acute abdomen resulting from torsion
Initially mistaken for a pelvic or lower abdominal tumor
The characteristic features of hypersplenism are
- Splenomegaly
- Blood cytopenias
- Absence of other causes of cytopenias (eg, anemia caused by bleeding)
Thrombocytopenia is a common finding in patients with:
Hepatic cirrhosis, portal hypertension, and splenomegaly
TRUE OR FALSE
The presence of thrombocytopenia or leukopenia in patients with chronic liver disease is associated with increased mortality.
TRUE
The presence of thrombocytopenia or leukopenia in patients with chronic liver disease is associated with increased mortality.
Decompensated liver disease and history of alcohol consumption are independent risk factors for hypersplenism, but why some patients develop marked blood cytopenias is not clear, although folate deficiency is a factor in some instances.
TRUE OR FALSE
The response to transfusion of blood products, especially platelets, is not affected in patients with massive splenomegaly.
FALSE
The response to transfusion of blood products, especially platelets, may be significantly impaired in patients with massive splenomegaly.
Indications for total spenectomy
- Abdominal trauma and partial rupture of the spleen
- Splenic size or infarcts causes sustained left upper abdominal pain or discomfort
- Treatment of functionally significant blood cytopenias
The most common indications for splenectomy
- Hereditary spherocytosis
- Immune thrombocytopenia
- Immune hemolytic anemia
Others: thalassemia major, sickle cell anemia
Improving cell survival and also by decreasing autoantibody production.
TRUE OR FALSE
Splenectomy in patients with a massive spleen size (>1500 g), especially in CML, is accompanied by higher morbidity and mortality than is removal of the spleen for immune blood cytopenia.
FALSE
Splenectomy in patients with a massive spleen size (>1500 g), especially in primary myelofibrosis, is accompanied by higher morbidity and mortality than is removal of the spleen for immune blood cytopenia.
An advantage of open splenectomy in hematologic conditions such as the treatment of immune thrombocytopenia is
Ease of searching assiduously for accessory spleens
Systemic complications after splenectomy
- Infections from encapsulated organisms
- Venous and arterial thromboembolic events
Modes of doing partial splenectomy
- Ligation of some of the splenic arteries
- Arterial embolization
It can be used in patients with an absolute contraindication to splenectomy who might benefit symptomatically from reduction of a massively enlarged spleen
Splenic Radiation
Splenic radiation may be associated with severe cytopenias and especially thrombocytopenia termed as
Abscopal effect
TRUE OR FALSE
Thrombocytopenia may not be corrected after liver transplant if the splenomegaly persists.
TRUE
Thrombocytopenia may not be corrected after liver transplant if the splenomegaly persists.
Thrombopoietin Receptor Agonists have studies that it increase platelets in patients with thrombocytopenia as a result of
Hepatitis C virus–related cirrhosis
The designation for decreased splenic function resulting from:
* Diseases that impair function
* Absence of splenic tissue because of agenesis, atrophy (eg, autoinfarction of sickle cell disease), or splenectomy
Hyposplenism
TRUE OR FALSE
Splenic hypofunction may be associated with a normal spleen size.
TRUE
Splenic hypofunction may be associated with a normal spleen size.
Infectious disease that cause hyposplenism
- Malaria
- Disseminated meningococcemia
PBS findings in hyposplenism
Howell-Jolly bodies and erythrocyte pits
The most common causes of hyposplenism
- Sickle cell anemia
- Surgical splenectomy
TRUE OR FALSE
Although the presence of an enlarged spleen usually suggests hypersplenism, spleen size is not a reliable index of splenic function.
TRUE
Although the presence of an enlarged spleen usually suggests hypersplenism, spleen size is not a reliable index of splenic function.
Example of hyposplenic splenomegaly
Complete splenic replacement by cysts, neoplastic tissue, or amyloid
Congenital asplenia may be found in infants with _________ and other developmental abnormalities.
Situs inversus
TRUE OR FALSE
Splenic replacement by neoplastic cells, as in lymphomas and leukemias, usually does not cause hyper- or hyposplenism.
TRUE
Splenic replacement by neoplastic cells, as in lymphomas and leukemias, usually does not cause hyper- or hyposplenism.
Hematologic
Splenectomy in children should be deferred until _____years of age.
5 years of age
The risk of overwhelming sepsis post splenectomy is reduced by the use of
Pneumococcal and H. influenzae vaccines before splenectomy and prophylactic penicillin therapy
The most specific of all the blood findings
Pitted erythrocytes in wet preparations
Other blood findings: Howell-Jolly bodies, target cells, Pappenheimer (siderotic) bodies, and occasional acanthocytes
Followed by the presence of DNA inclusions in circulating red cells (Howell-Jolly bodies)
Target cells reflecting an increased red cell surface are almost always present in the asplenic state, but only 1 in 100 to 1 in 1000 red cells is affected
A sensitive indication of hyposplenism
Pits or pocks on the cell surface
Pits or pocks on the cell surface consist of
Submembranous vacuoles
Can be seen only in wet preparations of red cells using direct interference-contrast microscopy
A reliable measure of the capacity of the spleen to clear particulate matter from the bloodstream
Spleen scanning with Technetium-99m sulfur-colloid particle
Antibiotic prophylaxis for asplenic patients that is recommended based on publicized guidelines
Oral penicillin or a macrolide antibiotic
TRUE OR FALSE
All asplenic patients with any febrile episode (>38°C) should be considered an emergency requiring immediate medical attention.
TRUE
All asplenic patients with any febrile episode (>38°C) should be considered an emergency requiring immediate medical attention.
