GI Section VIII: Spleen Flashcards
spleen reaches its normal adult size by the age of?
15
The spleen
Contains Red and White pulps
Red pulp = blood
20 HU less dense than the liver
More echogenic than the liver
The splenic artery arises from?
The celiac trunk
Essentially an end vessel with minimal collaterals
Pathology involving the spleen can be categorized as
Congenital
Aquired (trauma - portal HTN)
Mass
Normal Spleen on MRI
The spleen is basically a?
a big watery lymph node.
It restricts diffusion (like a lymph node).
Accessory Spleens (Splenule):
- Can mimic a pancreatic tail mass or a bad lymph node
- They will often follow the spleen on different CT contrast phases
- hey can hypertrophy
Cause of splenic hypertrophy
POst splenectomy
ITP
AHA
a wandering spleen is associated with
abnormalities of intestinal rotation.
The other key piece of trivia is that unusual locations set the spleen up for
torsion and subsequent infarction
A chronic partial torsion can lead to gastric varices.
the most common solid organ injured in trauma
Spleen
occurs post trauma where a smashed spleen implants and then recruits blood supply.
Splenosis
If the diaphragm has been ruptured - they can be pleural based nodules.
What can confirm that the implants are splenosis?
Tc Sulfur colloid (or heat-treated RBC)
Absent spleen + lots of soft tissue masses + Hx of trauma =
Think splenosis
if you think mets, check and make sure the spleen is normal.
These are small foci of hemorrhage in the splenic parenchyma that are usually associated with portal hypertension. They are T2 dark.
Gamna Gandy Bodies (Siderotic Module):
Gamna Gandy Bodies (Siderotic Module)
Gradient is the most sensitive sequence.
his is a rare condition characterized by multiple blood filled cyst-like spaces in a solid organ
Peliosis
most common visceral arterial aneurysm.
Splenic artery aneurysm
Pseudoaneurysm can occur in the setting of
Trauma and pancreatitis
The incidence is higher in women of
child bearing age who have had two or more pregnancies {4x more likely to get them, 3x more likely to rupture).
Splenic Artery Aneurysm are usually
Saccular and in the mid-distal artery
Don’t call them a hypervascular pancreatic islet cell mass and biopsy them.
frequently occurs as the result of pancreatitis. Can also occur in the setting of diverticulitis or Crohn’s.
Can lead to isolated gastric varices.
Splenic Vein Thrombosis
Infarction imaging features
a wedge-shaped, peripheral, low attenuation defect.
Most common radiologically detected splenic infection
histoplasmosis (with multiple round calcifications)
Another possible cause of calcified granuloma in the spleen
brucellosis
Solitary
> 2cm
SPleni abscess by brucillosis
a low density center, encircled by calcification giving the lesion a “bull’s eye” appearance.
Felty’s Syndrome
abnormality of granulocytes, with a triad:
(1) Splenomegaly, ^
(2) Rheumatoid Arthritis,
(3) Neutropenia
the most common cystic lesion in the spleen
Post traumatic cysts (pseudocysts)
Secondary to:
Infection
Infarction
Hemorrhage
Extension from pancreatic pseudocyst
PSeudo = no epithelial linging
the second most common cystic lesion in the spleen
Epidermoid cysts
Congenital
the third most common cystic lesion in the spleen.
Hydatid or Echinococcal cysts
Hydatid or Echinococcal cysts
the most common benign neoplasm in the spleen
Hemangioma
Splenic lymphangiomas
RAre
Most occur in childhood
MAy be solitary/multiple in a subscapular
Diffuse lymphangiomas may occur
hyperdense if there is hemosiderin deposition.
Hamartomas
Littoral Cell Angioma
hypoattenuating on late portal phase
MRI: hemosidering (low T1 and T2)
it is highly unlikely that you will encounter a primary malignancy of the spleen
but ifyou do it’s likely to be?
Vascular
The most common malignancy in the spleen
Angiosarcoma
Angiosarcoma
poorly defined area of heterogenicity or low density in an enlarged spleen
Angiosarcoma
can occur from prior thorotrast exposure.
SPlenic angiosarcoma
the most common primary neoplasm that mets to the spleen.
Melanoma
