Applied Pathology

1
Applied Pathology

• Module 2 Pathology of the spleen

2
Anatomy and physiology readings

• http//en.wikipedia.org/wiki/Spleen
• http//www.theodora.com/anatomy/the_spleen.html

3
Stomach
spleen
Capsule trabecula Red pulp White pulp
4
http//www.defra.gov.uk/animalh/diseases/images/v2
/asfn_5.jpg
Enlarged spleen (splenomegaly) on top and normal
spleen on bottom
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Splenomegaly

• Neoplasia
• Diffuse whole organ
• Congestion
• Blood collecting passively
• Erythropoiesis
• Production of red and white blood cells
• Inflammation
• Infectious process

6
Splenomegaly. There is generalized
enlargement of this cat spleen. The organ is
bulging and has rounded edges.
7
Splenomegaly. The diffuse enlargement of
this horse spleen is inflammation caused by the
equine infectious anemia virus
8
Splenic nodules

• Chronic nodular hyperplasia
• Common in old dogs
• Neoplasia
• Hemangiosarcoma (tumor of blood vessels)
• Lymphosarcoma (tumor of lymphocytes)
• Abscess
• Purulent (neutrophils)
• Pyogranulomatous
• Hematoma
• blood

9
There is focal nodular enlargement of this
dog spleen. This is splenic nodular hyperplasia
in an old dog. It is a common aging change and
not associated with cancer or inflammation.
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The nodules on this horse spleen are caused by
cancerous lymphocytes. This is lymphosarcoma.
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The dark nodules on this horse spleen are caused
by a tumor of melanocytes. This is malignant
melanoma.
12
The pale areas in this cow spleen are due to
inflammation caused by a bacterial infection.
13
End of Module 2

• Proceed to Module 3 Pathology of the liver.