spleen powerpoint Flashcards
2 main functions of spleen
- Defense against disease
* Produces lymphocytes and plasma cells
* prevents infection (especially in children) - Erythropoiesis
* In fetal period, responsible for producing
erythrocytes (RBC)
* although bone marrow assumes the function after
birth, spleen retains capacity to produce red blood
cells throughout life - Destruction and removal of defective red blood cells
- Acts as storage depot
how does the spleen defend against disease?
- Produces lymphocytes and plasma cells
- prevents infection (especially in children)
where does the Destruction and removal of defective red blood cells occur
mainly in the cord of Billroth
- Destroys aged RBCs and metabolizes their iron for
reuse in hemoglobin - Removes defective cells (i.e. spherocytes, sickle cells,
and thalassemic cells); called culling - Cells with a granular inclusion or parasites are not
culled, only the extraneous material is removed and
RBC returned to circulation; called pitting
what is culling
removal of defective cells
what is pitting
removal of the extraneous material and rbc returned to circulation
how does the spleen act as storage depot
- Stores iron and other metabolites
- Pooles platelets in large numbers
spleen Echogenicity is comparable to the ________
liver
spleen pathology
Changes in size Trauma
* Splenomegaly - Hematoma
* Atrophy - Splenic rupture
Focal lesions Diffuse Diseases
* Abscesses - Sickle cell anemia
* Infarcts - Hemolytic anemia
* Cysts - Polycythemia vera
* Tumors - Thalassemia
- Leukemia
name pathology
Clinical symptoms include LUQ fullness or pain, jaundice,
lymphadenopathy, fever, or hemorrhage
>13cm
spleenomegaly
name pathology
- Occurs in “wasting” diseases (chronic hemolytic
anemias) - Characterized by an excessive loss of pulp, increasing
fibrosis, scarring, and incrustation with iron and
calcium deposits - Spleen may get very small
atrophy
- Calcifications
- Sickle-Cell anemia
- Polycythemia vera
- Thalassemia
- Leukemia
- Aids
diffuse diseases
- Appear echogenic
- Demonstrate varying degrees of shadowing
- Can be caused by granulomatous disease -
histoplasmosis, or TB - Can result from previous infarction or hematoma
SPLENIC CALCIFICATIONS
- Early stages, spleen is enlarged
- Later, spleen undergoes progressive infarction and
fibrosis
SICKLE-CELL ANEMIA
- An abnormal proliferation in bone marrow elements,
red cell mass, and total blood volume - Spleen is variably enlarged
- Infarcts and thrombosis are common
POLYCYTHEMIA VERA
- Synthesis of normal hemoglobin is suppressed
- Spleen is VERY large
THALASSEMIA
2 types of leukemia
both produce inhomogeneous spleen
Chronic myelogenous leukemia
Chronic lymphocytic leukemia
which form of leukemia forms the largest spleenomegaly
chronic myelogenous leukemia
A progressive, malignant
disease of the blood-
forming organs,
characterized by distorted
proliferation and
development of leukocytes
leukemia
- Frequently accompanied by infections and lymphoma
- Splenomegaly is common
- May appear as hypodense nodular implants within
splenic parenchyma
AIDS
4 focal lesions of spleen
- Abscess
- Infarcts
- Cysts
- Neoplasms
abscess description
Single, focal abscesses within spleen are uncommon
* More often multiple
* Result from infection
* Complex in appearance; mixed echogenic properties
* Similar appearance to metastatic lesions and hematomas
* Pt presents with classic signs of infection (fever,
tenderness, WBC elevated)
INFARCTION ultrasound description and why it happens
Disruption of the blood flow to the organ. Sonographically
appears as a well-demarcated, hypoechoic wedge-shaped or
round area located at the periphery of the organ, ranging
from 1-2 cm (becomes increasingly echogenic with time)
can spleen cyst be congenital
yes and can also be acquired
ACQUIRED SPLEEN CYST ARE EITHER _________
OR _________
PARASITIC
NON-PARASITIC
Cystic disease of the spleen is an (common/uncommon) condition and the majority of cases are due to parasitic infection with Echinococcus granulosus resulting in hydatid disease
uncommon
- Epidermoid cysts - congenital
- Usually solitary and unilocular
- Rarely contain calcification
- More common in females
- Should demonstrate characteristics of cyst
spleen primary cyst
Spleen is most frequently damaged organ in blunt
abdominal trauma:
* Fracture of capsule
* Parenchymal lacerations
* Focal parenchymal or subcapular hematoma
tumors- spleen
* Rare
* Benign or malignant
* Benign tumors are generally isoechoic and will
demonstrate splenomegaly
BENIGN
Hamartoma
Hemangioma
Cystic lymphangioma
MALIGNANT
Lymphoma
Hodgkin’s tumor
Hemangiosarcoma
- Composed of lymphoid tissue and normal splenic
tissue (an overgrowth of mature cells & tissues that
normally occur in the spleen) - Has both solid and cystic components
- Generally hyperechoic
- May be solitary or multiple
- Well defined-not encapsulated
HAMARTOMA
- Most common benign neoplasm of the spleen
- 1:600 at autopsy
- Either capillary or cavernous types
- Sonographic appearance is variable
- May be complicated by rupture
- May be isoechoic or complex making it difficult to
sonographically differentiate from other splenic processes
HEMANGIOMA
- A malformation of lymphatics
- Appears as mass with extensive cystic spaces
- Usually involves multiple organs
- Rarely involves spleen
CYSTIC LYMPHANGIOMA
- Usually begins in lymph nodes, the most common site of
extranodal involvement is spleen, but primary disease in
spleen is rare - Irregular tumor-like nodules will appear in the spleen
- Sonographically may appear as focal hypoechoic or
hyperechoic masses, diffuse splenomegaly, or normal splenic
contour and size
HODGKIN’S TUMOR (malignant neoplasm)
- Rare, but most common PRIMARY splenic malignancy
- Arises from vascular endothelium of spleen
- Usually has a mixed cystic ultrasound pattern—and/or
may be hyperechoic - Grow rapidly and metastasize early
- May rupture spontaneously due to fast growth
HEMANGIOSARCOMA(malignant neoplasm)
- Metastasis is uncommon
- ___________ is most frequent metastatic lesion within
spleen (board question) - Also can spread from lung, breast, pancreas, and
ovary—there is no way for us to know where it came
from
Melanoma
- _______________________- is a term that refers to
a group of cancers of the lymphatic system (there are
many types and sub-types of NHL) - These cancers can have different symptoms and signs,
findings on a physical examination, and treatments. - May result in splenic enlargement
Non-Hodgkin lymphoma (NHL)
