Spleen

Question 0

What is the average adult spleen size?

Answer 0

12 cm – longitudinal
8 cm – transverse
4 cm – thickness

Question 1

What is the largest lymphoid organ that filters damaged cells, micro organisms and particulate matter?

Answer 1

The spleen

Question 2

What are the indications for splenomegaly?

Answer 2

Longitudinal measurement greater than 12 cm or if the spleen is inferior to the lower pole of the left kidney

Question 3

When is the left lobe of the liver seen anterior to the spleen?

Answer 3

If the left lobe is enlarged

Third trimester pregnancy

Question 4

Where are the fundus of the stomach, lesser sac and pancreatic tail located in relation to the spleen?

Answer 4

Medial and anterior to the splenic hilum

Question 5

What is a normal variant that is commonly found with a spleen?

Answer 5

Accessory spleen

Question 6

Where are accessory spleens normally located?

Answer 6

Near the splenic hilum with identical echogenicity to the adjacent spleen

Question 7

What are splenic granulomas?

Answer 7

Focal lesions resulting from previous infections

Question 8

What are the most common causes of splenic granulomas?

Answer 8

Histoplasmosis and tuberculosis

Question 9

What are some splenic calcifications associated with?

Answer 9

Splenic artery wall calcifications
Splenic artery aneurysms calcifications
Pneumocystis carinii infection
Splenic infarcts

Question 10

List examples of cystic lesions found in the spleen.

Answer 10

Autosomal dominant polycystic disease
Hydatid cysts
Epidermoid cysts
Liquefied infarcts or hematomas
Pancreatic pseudocysts

Question 11

What are epidermoid cysts of the spleen?

Answer 11

True cysts lined by squamous epithelium

Question 12

What are the most common benign primary neoplasms of the spleen?

Answer 12

Hemangiomas

Question 13

What is the most common metastases to the spleen?

Answer 13

Malignant melanoma

Question 14

How do you metastatic lesions commonly appear in the spleen on ultrasound?

Answer 14

Hypoechoic, but the appearance may vary

Question 15

Splenic infarct are commonly associated with what disease process?

Answer 15

Bacterial endocarditis

Splenic artery aneurysms

Question 16

How do you splenic infarcts appear on ultrasound?

Answer 16

Wedge shaped hypoechoic lesion

Question 17

What are splenic abscesses a result of?

Answer 17

Sepsis due to endocarditis, dental infections or urosepsis

Question 18

How do splenic abscesses appear sonagraphically?

Answer 18

Complex cystic lesions

Presence of gas may produce echogenic foci with an associated reverberation artifact

Question 19

What happens to the spleen in sickle cell disease?

Answer 19

Spleen enlarges at the end of the first year of life
Spleen remains enlarged because of splenic sequestration
Over time, the spleen becomes fibrotic and shrinks (autosplenectomy)

Question 20

What are different mechanisms that cause splenomegaly?

Answer 20

Congestive
Immune response hypertrophy
RBC destruction hypertrophy
Myeloproliferative
Infiltrative
Neoplastic

Question 21

What is the most common mechanism for splenomegaly?

Answer 21

Congestive

Portal hypertension and splenic vein thrombosis

Question 22

What is polycythemia vera?

Answer 22

Blood disorder resulting in uncontrolled RBC production causing hyperviscosity and hypercoagulation

Question 23

How does a splenic artery aneurysm appear on x-ray?

Answer 23

Calcified circle seen in the left upper quadrant

Question 24

How does a splenic artery aneurysm appear on ultrasound?

Answer 24

Cystic mass | If calcified, a hyperechoic shadowing foci near the splenic hilum

Question 25

What are heterotaxy syndromes?

Answer 25

Spectrum of situs disorders with a wide range of findings

Question 26

What is situs solitus?

Answer 26

Normal asymmetrical arrangement of anatomy

Question 27

What is situs inversus?

Answer 27

Mirror image of situs solitus

Question 28

What is situs ambiguous or heterotaxia?

Answer 28

Disruption in the development of normal asymmetric arrangement abdominal organs and vessels

Question 29

What are the two classifications of heterotaxy?

Answer 29

Polysplenia and asplenia

Question 30

What is polysplenia associated with?

Answer 30

``` Multiple LUQ spleens Biliary atresia/absent gallbladder Intestinal malrotation Azygous continuation of interrupted IVC Cardiac defects ```

Question 31

What is asplenia associated with?

Answer 31

``` Absent spleen Midline liver and gallbladder Intestinal malrotation Reversed positions of aorta and IVC Cardiac defects ```

Question 32

When do splenic subcapsular and intraparenchymal hematomas occur?

Answer 32

Trauma where the capsule remains intact

Question 33

When do perisplenic or intraperitoneal hematomas occur?

Answer 33

Splenic trauma when the capsule ruptures

Question 34

How does intraperitoneal blood appear on ultrasound?

Answer 34

Depends on the age, amount and physical state of the clot

Question 35

What is hematocrit?

Answer 35

Volume of red blood cells found in 100ml of blood

Question 36

What is posttraumatic splenosis?

Answer 36

Ectopic spleen that occurs in the patient with a history of splenic rupture or surgery where splenic cells implant throughout the peritoneal cavity (autotransplantation)