CH 11 Pediatric Spleen Flashcards
Spleen
intraperitoneal organ located in the LUQ. part of the reticuloendothelial system (** responsible for phagocytosis = engulfing and destroying of damaged/old cells and their debris, foreign material and pathogens and taking them out of the circulating blood)
largest lymphoid organ (primarily lymph tissue)
not essential for life (you can live without)
Spleen sono:
neonate- is iso- or hypoechoic relative to kidneys.
by end of first year of life, it becomes hyperechoic relative to the kidneys.
Accessory Spleen
arises from failure of the individual clumps of mesenchyme to fuse during development. Usually single and found at the splenic hilum.
may be found attached to the left ovary or within the scrotum due to the relationship of splenic, mesonephric and left gonadal development.
can hypertrophy if spleen is removed
Wandering spleen
spleen is highly mobile and on a long/absent pedicle.
common in “prune belly” syndrome.
Splenic torsion
twisting may occur compromising the blood supply.
In acute torsion a large, hypoechoic spleen will be seen due to infarction and congestion.
In chronic torsion the spleen will be very small and difficult to image.
Polysplenia (heterotaxy syndrome)
- Left isomerism, multiple splenules
more common in females.
present with midline liver, malrotated bowel, absent GB, bilateral BI-lobed lungs, interrupted intrahepatic IVC, with an azygous or hemiazygous continuation.
Asplenia
*right isomerism, absence of spleen
more common in males
associated: complex cyantoic congenital heart disease, transposition of the great vessels, absent GB, bilateral TRI-lobed lungs and transverse liver.
Situs Inversus
congenital condition where the major visceral organs are reversed or “mirrored”
Spleen on the Right, Liver on the Left.
Splenomegaly causes:
Hepatomegaly- issue with splenic v or portal v leukemia ECMO infiltrative storage disorders mononucleosis infections focal lesions portal HTN heart failure lymphoma hemolytic anemias
Small spleen causes:
Infarction due to wandering spleen/ sickle cell anemia
congenital absence or hypoplasia
partial splenectomy
celiac dz
fanconi anemia (rare, inherited disorder, common in Jewish descent and South Africans, leads to bone marrow failure.
Splenic cysts
may be congenital (true epithelial or epidermoid) or aquired (false or pseudocysts- post traumatic)
they may rupture or become infected.
can not differentiate between congenital and aquired by ultrasound
Congenital Splenic cysts
epithelial lining and imperceptible walls.
cysts secondary to a hematoma or infective process will have no epithelial lining. Post-traumatic cysts have thicker walls and may be calcified.
Epidermoid splenic cysts
primary congenital cyst, well-defined cystic lesions which may have calcifications present in the cyst or wall. May be septated and have internal echoes due to hemorrhage.
Hydatid cyst (spleen)
from ruptured liver cyst or systemic infection (due to parasites)
well-defined, may be single or multiple and have wall calcifications.
Lymphangiomas of Spleen
rare multiple cystic spaces of variable thickness, filled with lymph, which have vascular spetations.
Hemangiomas of Spleen
common benign neoplasms. similar in appearance to those in liver of adults.
associated with: beckwith-wiedemann syndrome, klippel-trenaunay-weber, turners syndrome, and Kasabach-Merrit syndrome (large hemangioma which causes platelet trapping and damage resulting in disseminated intravascular coagulation - may be fatal)
appearance varies due to size of vessels
Abscesses in spleen
have thick walls and internal echoes and are usually > 1.5 cm. Form due to the spread of infection through the bloodstream.
Abscess is a collection of pus within the splenic parenchyma.
Children with splenic abscesses are usually immunocompromised.
spread due to appendicitis, empyema, osteromyelitis, bacterial endocarditis or ear infection.
Fungal abscesses in liver
seen in cases of candida, aspergillus and cryptococcus.
“bull’s-eye” or “target” appearance and are usually small
Candida abscesses (spleen)
occur in immunocompromised children
Cat-scratch disease
can cause multiple splenic abscesses
Splenic calcifications
may be due to histoplasmosis or TB
caves in midwest
Neoplastic conditions of spleen
Lymphoma and leukemia are the most common.
The spleen may be involved in a focal or diffuse manner.
Lymphoma
may cause enlargement of the spleen and focal hypoechoic lesions within the parenchyma (hypo- or hyperechoic appearance)
Leukemia
hypo- or hyperechoic parenchyma with enlargement of the spleen. may see small focal lesions.
big spleen, usually no lesions seen
*Langerhans cell histiocytosis
proliferation of the hisiocytes involving the skin, bone marrow, reticuloendothelial system and lungs.
Enlarged spleen with multiple focal hypoechoic nodules is seen.
*Gaucher disease
congenital storage disorder where the enzyme glucocerebrosidase is lacking. This enzyme breaks down a fatty substance, glucocerbroside. Without enzyme glucocerebroside builds up to toxic levels and accumulates in the liver and spleen.
causes hyper- or hypoechoic nodules in the spleen. Extramedullary hemopoiesis (failure of RBC development in the bone marrow) infarction and fibrosis of the spleen.
Splenic infarction
Spleen in very vulnerable to infarction.
*sono infarcts appear wedge-shaped
conditions causing infarcts: sickle cell splenic torsion cardiac emboli vascular diseases portal HTN (rarely)
following splenic infarct pseudocyst formation or rupture of the infection with abscess formation may occur.
Splenic peliosis
rare condition associated with TB, steroid therapy, and hematologic malignancies, leishmaniasis (a rare tropical parasitic infection, middle east).
Blood-filled spaces are seen in the spleen with this condition.
Splenic trauma
usually due to abdominal trauma. *Spleen is the most commonly injured solid organ in children.
abnormalities may include: lacerations, subcapsular hematoma, hematoma, fracture or rupture of the spleen.
Acute bleeding hyperechoic and may be difficult to distinguish from normal splenic tissue.
subcapsular fluid will present as a crescent-shaped collection seen just beneath the capsule.
Splenic rupture
fluid in the flank or rest of the abdomen will be seen.
*Splenosis
when the spleen is injured, splenic tissue scatters throughout peritoneal cavity.