57 Hypersplenism and Hyposplenism

Question 1

Defined as blood cytopenias in the setting of splenomegaly

Answer 1

Hypersplenism

Accompanied by hyperplasia of the affected cell precursors in the marrow

Question 2

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.

Answer 2

First trimester

Question 3

Genes are essential for spleen formation, and defects in their expression result in hyposplenia or asplenia

Answer 3

HOX11 and WT1 genes

Question 4

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).

Answer 4

Second trimester

CD4+ lymphocytes

Question 5

CD8+ cells reside in_______________ and a specialized subset of γδT cells home to the_________

Answer 5

Splenic cords

Pulp

Question 6

Immunoglobulin (Ig) D+ and IgG+ B lymphocytes form localized deposits, the (primary or secondary) lymph follicles.

Answer 6

Primary lymph follicles

Question 7

(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.

Answer 7

Secondary follicles

Question 8

The normal adult spleen weighs _______and has a blood flow that is approximately ____% of the cardiac output.

Answer 8

135 ± 30 g

5%

Question 9

The spleen is composed of (3 components)

Answer 9

White pulp, a marginal zone, and red pulp

Question 10

Approximately__________ of platelets are normally sequestered in the spleen

Answer 10

One-third

Question 11

TRUE OR FALSE

The red pulp plays a major role in adaptive immunity.

Answer 11

FALSE

The white pulp plays a major role in adaptive immunity.

Question 12

The spleen is involved in the phagocytosis of encapsulated bacteria, including:

Answer 12

Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis

Question 13

The benefits of splenectomy in immune thrombocytopenia is a result of :

Answer 13

Decreased production of antiplatelet antibodies

Decreased clearance by macrophages of antibody-coated platelets through the Fc recognition function of its large macrophage population

Question 14

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.

Answer 14

Portal hypertension

Question 15

Causes of Massive Splenomegaly

Answer 15

1. Myeloproliferative disorders
   a. Primary myelofibrosis
   b. Chronic myeloid leukemia
2. Lymphomas
   a. Hairy cell leukemia
   b. Chronic lymphocytic leukemia (especially
   prolymphocytic variant)
3. Infectious
   a. Malaria
   b. Leishmaniasis (kala azar)
4. Extramedullary hematopoiesis
   a. Thalassemia major
5. Infiltrative
   a. Gaucher disease

Question 16

TRUE OR FALSE

Slight to moderate enlargement of the spleen usually does not produce local symptoms. Even massive splenomegaly can be well tolerated if it develops gradually.

Answer 16

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.

Question 17

Splenic rupture is uncommon but can occur spontaneously with most causes of:

Answer 17

Splenic enlargement or after blunt trauma

Question 18

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.

Answer 18

TRUE

Generally, a palpable spleen signifies splenomegaly and is measured by the number of centimeters the spleen extends below the left costal margin.

Question 19

Splenic size is most accurately measured with

Answer 19

Abdominal ultrasound or computed tomographic scans

Question 20

Imaging used primarily to identify cysts, abscesses, and infarcts

Answer 20

Magnetic resonance imaging

Question 21

A wandering spleen

An uncommon phenomenon in which the spleen hangs by a long pedicle of mesentery

Answer 21

Splenoptosis

Question 22

Splenoptosis may present in three ways:

Answer 22

(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

Question 23

The characteristic features of hypersplenism are

Answer 23

Splenomegaly, blood cytopenias, and absence of other causes of cytopenias (eg, anemia caused by bleeding)

Question 24

Thrombocytopenia is a common finding in patients with:

Answer 24

Hepatic cirrhosis, portal hypertension, and splenomegaly

Question 25

TRUE OR FALSE

The presence of thrombocytopenia or leukopenia in patients with chronic liver disease is associated with increased mortality.

Answer 25

TRUE

The presence of thrombocytopenia or leukopenia in patients with chronic liver disease is associated with increased mortality.

Question 26

Ultrasound-guided fine-needle biopsy of the spleen can be useful in circumstances in which the spleen holds the tissue required for diagnosis, such as ___________

Answer 26

Splenic lymphoma

Question 27

TRUE OR FALSE

The response to transfusion of blood products, especially platelets, is not affected in patients with massive splenomegaly.

Answer 27

FALSE

The response to transfusion of blood products, especially platelets, may be significantly impaired in patients with massive splenomegaly.

Question 28

Indications for total spenectomy

Answer 28

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

Question 29

The most common indications for splenectomy

Answer 29

Hereditary spherocytosis, immune thrombocytopenia, and immune hemolytic anemia

Question 30

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.

Answer 30

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.

Question 31

An advantage of open splenectomy in hematologic conditions such as the treatment of immune thrombocytopenia is

Answer 31

Ease of searching assiduously for accessory spleens

Question 32

Systemic complications after splenectomy

Answer 32

Infections from encapsulated organisms and venous and arterial thromboembolic events

Question 33

Modes of doing partial splenectomy

Answer 33

Ligation of some of the splenic arteries

Arterial embolization

Question 34

It can be used in patients with an absolute contraindication to splenectomy who might benefit symptomatically from reduction of a massively enlarged spleen

The procedure may be associated with severe cytopenias and especially thrombocytopenia (abscopal effect)

Answer 34

Splenic Radiation

Question 35

TRUE OR FALSE

Thrombocytopenia may not be corrected after liver transplant if the splenomegaly persists.

Answer 35

TRUE

Thrombocytopenia may not be corrected after liver transplant if the splenomegaly persists.

Question 36

The designation for decreased splenic function resulting from diseases that impair function or from the absence of splenic tissue because of agenesis, atrophy (eg, autoinfarction of sickle cell disease), or splenectomy

Answer 36

Hyposplenism

Question 37

TRUE OR FALSE

Splenic hypofunction may be associated with a normal spleen size.

Answer 37

TRUE

Splenic hypofunction may be associated with a normal spleen size.

Question 38

Infectious disease that cause hyposplenism

Answer 38

Malaria
Disseminated meningococcemia

Question 39

PBS findings in hyposplenism

Answer 39

Howell-Jolly bodies and erythrocyte pits

Question 40

The most common causes of hyposplenism

Answer 40

Sickle cell anemia and surgical splenectomy

Question 41

TRUE OR FALSE

Although the presence of an enlarged spleen usually suggests hypersplenism, spleen size is not a reliable index of splenic function.

Answer 41

TRUE

Although the presence of an enlarged spleen usually suggests hypersplenism, spleen size is not a reliable index of splenic function.

Question 42

Example of hyposplenic splenomegaly

Answer 42

Complete splenic replacement by cysts, neoplastic tissue, or amyloid

Question 43

Congenital asplenia may be found in infants with _________ and other developmental abnormalities.

Answer 43

Situs inversus

Question 44

TRUE OR FALSE

Splenic replacement by neoplastic cells, as in lymphomas and leukemias, usually does not cause hyper- or hyposplenism.

Answer 44

TRUE

Splenic replacement by neoplastic cells, as in lymphomas and leukemias, usually does not cause hyper- or hyposplenism.

Question 45

Splenectomy in children should be deferred until _____years of age.

Answer 45

5 years of age

Question 46

The risk of overwhelming sepsis post splenectomy is reduced by the use of

Answer 46

Pneumococcal and H. influenzae vaccines before splenectomy and prophylactic penicillin therapy

Question 47

The most specific of all the blood findings

Answer 47

Pitted erythrocytes in wet preparations

Other blood findings: Howell-Jolly bodies, target cells, Pappenheimer (siderotic) bodies, and occasional acanthocytes

**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

Question 48

A sensitive indication of hyposplenism

Answer 48

Pits or pocks on the cell surface

Question 49

Pits or pocks on the cell surface consist of

Answer 49

Submembranous vacuoles

** can be seen only in wet preparations of red cells using direct interference-contrast microscopy

Question 50

Most specific evidence of hyposplenism

Answer 50

Vesicles are more numerous and enlarge, forming vacuoles–> Pits or pocks on the cell surface

**Followed by the presence of DNA inclusions in circulating red cells (Howell-Jolly bodies)

Question 51

A reliable measure of the capacity of the spleen to clear particulate matter from the bloodstream

Answer 51

Spleen scanning with Technetium-99m sulfur-colloid particle

Question 52

Antibiotic prophylaxis for asplenic patients that is recommended based on publicized guidelines

Answer 52

Oral penicillin or a macrolide antibiotic

Question 53

TRUE OR FALSE

All asplenic patients with any febrile episode (>38°C) should be considered an emergency requiring immediate medical attention.

Answer 53

TRUE

All asplenic patients with any febrile episode (>38°C) should be considered an emergency requiring immediate medical attention.