Lymphoid System Flashcards
Primary lymphoid organs
Thymus
Bone marrow
Bursa of Fabricius
Secondary lymphoid organs
Spleen
Lymph nodes
MALT
Tonsils
Causes of thymic pathology
Congenital
Atrophy
Inflammation
Hematoma
Neoplasia
Small lymph nodes
Developmental disorders
Lack of antigenic stimulation
Malnutrition
Aging
Viral infections
Enlarged lymph nodes
Hyperplasia +/- drainage
Lymphadenitis
Metastatic or primary neoplasia
Discoloration/pigment
Histiocytic sarcoma
Interstitial dendritic cell origin
Localized or disseminated forms
Splenomegaly / bloody spleen
Congestion (torsion, barbiturate euthansia)
Septicemia
Acute hemolytic anemia
Splenomegaly / meaty spleen
Chronic infectious disease
Chronic hemolytic anemia
Diffuse granulomatous disease
Disseminate follicular hyperplasia
Neoplasia
Storage material EMH
Nodular spleen with bloody consistency
Hematoma
Hemangiosarcoma
Incomplete/irregular contraction
Acute splenic infarct
Nodular spleen / firm consistency
Focal nodular hyperplasia
Granuloma or abscess
Neoplasia
Small spleen
Developmental (immunodeficiency disorder)
Atrophy (aging, wasting disease)
Contraction
Choristoma
Normal spleen in abnormal place
Siderofibrotic plaques
Hemosiderin
Common in old dogs
Tonsilar illness
Lymphoid depletion (viral infection)
Inflammation (primary/hematogenous infectious)
Inflammatory polyps - older dogs
Neoplasia
SCID
Genetic immunodeficiency
In horses: defect in catalytic subunit of DNA dependent protein kinase
In dogs: defect in common gamma chain of numerous cytokines; defect in catalytic subunit of DNA-dependent protein kinase (like in Arabian foals)
