Urinary + Spleen Test

Where is the spleen located?

LUQ between stomach and diaphragm in the left hypochondrium

T/F - The spleen is a peritoneal organ?

True

What does the spleen do?

Filters damaged cells, microorganisms and particulate matter

T/F - The spleen is the smallest lymphoid organ in the body

False; THE SPLEEN IS THE BIG DAWG OF LYMPHOIDS

What are the four main functions of the spleen?

The 4 main functions of the spleen are:

1. Destruction of RBC

2. Immune Response- produce WBC and antibodies

3. Hematopoiesis

4. Storage- RBC and platelets for emergencies

What is hematopoiesis?

Hematopoiesis-the process of creating blood cells, including red blood cells, white blood cells, and platelets, in the bone marrow

• In fetus, liver and spleen are responsible up until approx. 5^th month

• Then bone marrow takes over

RBC, most WBC, and platelets are produced in what?

The bone marrow

Normal blood cells last for hour long?

A few hours to a few days

Remember, the normal liver usually doesn’t touch the spleen unless it is enlarged

I see

Anatomic relationships:

Where do the fundus of the stomach, lesser sac, and pancreatic tail lie?

Medial and anterior to the splenic hilum

Anatomic relationships:

Where does the left kidney lie?

Inferior and medial to the spleen

What ligaments hold the awesome spleen in place?

1. Lienorenal ligament

2. Gastrosplenic ligament

3. Phreniococolic ligament

4. Phrenosplenic ligament

What does the spleen measure in an adult?

8-12 or13 cm in length

What does a spleen measure in a child?

5.7 cm  +  .31 x age in years to age 21

When is splenomegaly considered?

>13cm spleen OR if the spleen is inferior to the lower pole of the kidney

What is the normal sonographic appearance of the spleen?

fine uniform homogenous mid-to-low level echo pattern and be slightly more echogenic than the liver parenchyma.

• As the spleen enlarges, the echogenicity increases.

What is the vascular supply of the spleen?

Splenic artery and splenic vein

What da freak is Trabeculae of the spleen?

§connective tissue structures that extend from the spleen's capsule into the splenic parenchyma and provide a framework for the spleen, and form small spaces called areolae that contain the splenic pulp

What are the functional parts of the spleen?

Red and white pulp

What is red pulp?

Basically, a filter and does phagocytosis

Filters arteriole to venous blood passage

Old RBC break down - removed by phagocytic macrophages

What is white pulp?

The goat of immune response

Responsible for production of lymphocytes (WBC), plasma cells (antibodies), Functions similar to nodules of lymph nodes

How can Cirrhosis/Hepatitis affect the poor spleen?

Portal hypertension can cause the spleen to trap white   blood cells and platelets; Spleen enlarges due to increased liver pressure

How can hemolytic anemia affect the spleen?

Hemolytic anemia is basically a disorder in which red blood cells are destroyed faster than they can be made SO, if the spleen is the one that gets rid of RBC, it is basically contributing to the anemia because they are already less RBCs to begin with

How can lymphoma affect the spleen?

Lymphoma affects the spleen because the spleen is the largest lymphoid organ, so obvi cancer that begins in infection is gonna affect the spleen

what is another name for wandering spleen?

Splenoptosis

Wandering spleen?

Abnormally positioned spleen. Not attached properly by its suspensory ligaments; Usually migrates to lower abdomen

• Aka-ectopic, floating

Could be born with it or acquired and may cause torsion, which will then result in acute pain (yeeeouch)

Who is more susceptible to wandering spleen?

Pregnancy and multiparous women

Heterotaxia?

Congenital condition; major organs are abnormally positioned in the chest and abdomen. Occurs because of a failure in the normal establishment of left-right asymmetry during embryonic development, often resulting in complex congenital heart defects and other issues like malformed lungs or spleen abnormalities.

Heterotaxy syndrome affects an estimated 1 in _________ newborns worldwide?

10,000 but could be more common since it is often undiagnosed

What are other names for heterotaxia?

Situs ambiguous and visceral heterotaxy

What is situs solitus?

Type of visceral heterotaxy where organs are in normal position

What is situs inversus?

Type of visceral heterotaxy where organs are flipped/mirrored

What is situs ambiguous/hetetrotaxia?

Type of visceral heterotaxy where organs are just randomly placed in the body; Can be associated with polysplenia and asplenia

What are the characteristics of polysplenia?

1. LT SIDEDNESS

2. Multiple LUQ Spleens

3. Biliary Atresia, absent gallbladder

4. Azygous Continuation of IVC

   • IVC interrupted at level of Hepatic veins, blood from LE and kidneys

5. Intestinal malrotation and GI anomalies

6. Cardiac defects

7. Renal agenesis

8. 2 morphologic left lungs

9. Liver central or left side

Characteristics of asplenia

RT SIDEDNESS

Midline Liver and GB

Absent Spleen

Reversed positions of AO & IVC

Intestinal malrotation

Severe cardiac defects/anomalies

2 morphologic right lungs

What is Agenesis aka Asplenia aka RT isomerism

Failure of the spleen to develop; If the spleen is gone, the liver and lymph nodes take over the spleen’s duties; You can live without a spleen, but you could end up prone to more infections

Agenesis is what?

Strictly structural birth defect where da spleen is gone (technically the same as asplenia but the way it happened is different)

Asplenia

An umbrella diagnosis that covers those born without a spleen (agenesis), someone who had their spleen removed surgically after an accident (trauma splenectomy), or someone whose spleen has shriveled up and stopped working due to chronic illness like sickle cell anemia (functional asplenia)

Accessory/supernumerary spleen

Common variant (30% occurrence rate); Usually located in hilum and has the same echogenicity as the main spleen

Small rounded masses, less than 5 cm diameter

• May enlarge with splenomegaly

Ectopic accessory spleens may undergo torsion & cause severe abdominal pain (yeeeeouch)

Since the spleen is involved in all systematic inflammations, blood disorders, and lots of metabolic disorders, what usually happens to it as a result?

Splenic enlargement because it is fighting for its life

Auto splenectomy happens as a result of what?

Fighting off diseases like lupus, sickle cell, and/or infarction

What is splenomegaly?

When spleen is over 13cm in length; Most common feature of splenic disease

Da spleen will extend anterior, medial & inferior directions when it is enlarged

Who is splenomegaly most commonly associated with?

Adults with portal hypertension

What is congestion a primary cause of?

Splenomegaly, specifically portal hypertension and its little minions aka splenic vein thrombosis, cirrhosis, and congestive heart failure

What is infiltration a primary cause of?

Another primary cause of splenomegaly, specifically infiltration due to malignancies and depository diseases like amyloidosis (protein) and sarcoidosis (granuloma)

What is proliferation a primary cause of?

Another primary cause of splenomegaly where there is hyperfunctioning due to acute infection like mononucleosis

Amyloidosis?

Storage disease where there is a metabolic PROTEIN disorder

Diabetes mellitus?

Storage disease, which is also a metabolic disease, involving inappropriately elevated blood glucose levels

Gaucher disease?

Storage disease where there is a missing enzyme for lipid breakdown

Niemann-pick disease?

Storage disease where there is an inability of the body to transport cholesterol and other fatty substances

Hemachromatosis

Storage disease where there are excessive deposits of iron (remember the liver chapter)

What exactly is splenic congestion?

the pooling of blood in the spleen, often causing an enlarged spleen

Acute = moderately enlarged spleen; Chronic = greatly enlarged spleen

Causes:

• heart failure

• cirrhosis

• portal hypertension

• portal/splenic vein thrombosis

• cystic fibrosis

Polycythemia vera is what?

A blood disorder of uncontrolled RBC production which causes hyperviscosity and hypercoagulation

Polycythemia vera may also be the cause of what?

Splenomegaly

Budd-Chiari

Portal Vein thrombosis

Splenic Infarcts

What are some infections associated with the spleen?

• Hepatitis

• Infectious mononucleosis

• Tuberculosis

• Malaria/typhoid

• Histoplasmosis

• HIV/AIDS

• Bacterial infections

Hemolytic anemia is what?

General term meaning decrease in erythrocytes

Spherocytosis

Hereditary or congenital form of hemolytic anemia where erythrocytes are spherical rather than concave

Thalassemia

Type of hemolytic anemia where there is decreased hemoglobin due to abnormally shaped, small and pale, blood cells.

Very prevalent in Mediterranean people like (Greek/Italians)

What is sickle cell anemia?

Hereditary; Type of sickle cell disease where the spleen begins to enlarge at the end of 1st year of life and remains enlarged due to splenic sequestration (pooling of sickle cells); Due to repeated flares over time, the spleen will become fibrotic and shrink (autosplenectomy) before the end of childhood :(

Where is sickle cell anemia most common?

Most common in people of African descent, particularly sub-Sahara Africa, also prevalent

• Hispanic

• Middle Eastern

• South Asia

• Mediterranean

What are some neoplastic diseases of the spleen?

Leukemia (can cause extreme enlargement)

Lymphoma

Metastasis

What are some focal disease processes of the spleen?

Cyst, abscess, infarction, rupture, calcifications (granulomas), neoplasms, cavernous hemangioma, and splenic artery aneurysm

Hydatid splenic cyst

Parasitic cyst that is most common in the liver

Autosomal dominant polycystic disease

Type of splenic cysts where there are lots of cysts

Epidermoid cyst

 Ring like appearance-may have calcified rim; Average 10 cm in size; Internal contents may appear echogenic

What da helly is a splenic abscess?

Usually, a result of sepsis due to endocarditis, dental infections, or urosepsis; Sonographically seen as a complex cystic lesion. May also be gas-producing (comet tail)

What da helly is infarction of the spleen?

 Common with bacterial endocarditis and Splenic artery aneurysms

 Wedge-shaped hypoechoic lesion

◦Later anechoic, then calcify

Subcapsular/intraparenchymal hematoma

Type of rupture where the splenic capsule stays intact

Ruptures are best seen with which modality?

CT

Perisplenic/Intraperitoneal hematomas

Type of rupture where the capsule ruptures and fluid generally loculated around spleen although can spread within peritoneal cavity

What happens after a rupture of the spleen?

POSTTRAUMATIC SPLENOSIS- ruptured cells may implant throughout the body

Granuloma

Type of calcification most commonly caused by Histoplasmosis (bird droppings) and Tuberculosis (air droplets from sneeze or coughs); Could also be associated with splenic artery wall calcifications, splenic artery aneurysms, and splenic infarcts

What is the most common benign primary neoplasm of the spleen?

Hemangioma

Remember, primary neoplasms are RARE in the spleen (this basically means it is extremely rare for cancer to start in the spleen, it usually spreads from somewhere else)

I see

Malignant melanoma

Most frequent cancer to the spleen followed by breast and lung cancer

T/F - Metastases to the spleen is very common

False

Cancer of the spleen mostly looks how?

Commonly hypoechoic

What is the thymus?

Lymphatic organ that plays a vital role in the development of the immune system during childhood. The thymus is disproportionately larger in infants.

•  As children grow, and their immune system matures, the thymus undergoes physiologic involution.

Where is the thymus gland located?

Upper chest behind your breastbone (sternum). It sits between your lungs in a part of your chest called the mediastinum. Your thymus is just in front of and above your heart.

Remember, the kidneys are retroperitoneal organs that are bean shaped with a smooth capsule and the right one is lower than the left

Wow, so cool

What are nephrons?

located in the parenchyma, they are the functional unit of the kidney

Each kidney contains more than a million nephrons.

What are some super fun functions of the nephrons?

• filter waste products from the blood

• reabsorb water and nutrients (e.g., glucose and amino acids) from the tubular fluid

• secrete excess substances in the form of urine.