Department of Pathology, Faculty of Veterinary Medicine, Zagazig University, Egypt.
Pathology of Hemopoietic System BY
Prof. Dr. Mohamed Hamed Mohamed mohamedelariny@yahoo.com +201224067373
2012
Hemopoietic System It consists of 3 organs: 1-Lymph nodes 2-Spleen 3-Bone Marrow
(Lymphadenitis). (Splenitis). (Osteomyelitis).
Lymph nodes Lymphadenitis:
inflammation of lymph node (L.n.). I-Classification of lymphadenitis according to Duration: 1-Acute lymphadenitis 2-Chronic lymphadenitis II-Classification of lymphadenitis according to Exudate and Lesions: 1-Serous 2-Fibrinous 3-Suppurative 4-Hemorrhagic 5-Necrotic (caseous) 6-Gangrenous
Acute Lymphadenitis: Macroscopic Picture: 1-The affected L.n. is enlarged. 2-The affected L.n. is congested. 3-Soft and moist in Serous Lymphadenitis. -Firm in Fibrinous Lymphadenitis. -Pus on cut surface in Suppurative Lymphadenitis. -Hemorrhagic (dark red) Hemorrhagic Lymphadenitis. -Black wit bad odor in Gangrenous Lymphadenitis. -Friable cheesy material Necrotic Lymphadenitis.
Microscopic Picture: 1-Active hyperemia. 2-leukoctic infiltrations. 3-Hyperplasia of lymphocytes and REC.
4-Edema (Albumin) in Serous Lymphadenitis. -Fibrin threads in Fibrinous Lymphadenitis. -RBCs in Hemorrhagic Lymphadenitis. -Neutrophils and pus in Suppurative Lymphadenitis. -Loss of cellular details and tissue architecture in Necrotic Lymphadenitis. -Gas bubbles and mo.in Gangrenous Lymphadenitis.
Chronic Lymphadenitis: -Follow the acute type -T.B., Johne’s disease, Glanders, Actinobacillosis
Macroscopic Picture: 1-L.n. is enlarged 3-Firm
2-Edematous 4-Pink in color.
Microscopic Picture: 1-Fibrous connective tissue proliferation. 2-Hyperplasia of the lymphocytes and REC. 3-Caseation and calcification (TB). 4-Macrophages, epithelioid cells and giant cells infiltration.
Spleen Splenitis:
Inflammation of spleen.
I-Classification of Splenitis according to Duration: 1-Acute Splenitis (focal or diffuse)
2-Chronic Splenitis
II-Classification of Splenitis according to Exudate and Lesions: 1-Suppurative: 2-Hemorrhagic: 3-Necrotic: 4-Gangrenous:
pyogenic M.O. (pyemia). Septicemic D. (anthrax) or trauma S. necropherous, TB, Brucella Foreign body with saprophytic mo.
Splenomegaly: Enlargement of spleen as in case of chronic anemia.
Bone Marrow In Young Animals: the bone marrow present in the shaft of all long bones. In Old Animals: Red bone marrow present in epiphyses of long bones. Yellow bone marrow present in the shaft.
Gelatinous degeneration of B.M. Causes:
1-Bacterial toxins 2-Chronic debilitating diseases.
Lesions: The yellow and red bone marrow become gelatinous (Jelly-like structure).
Anemia: Polycythemia: Leukocytosis: Neutrophilia: Eosinophilia: Lymphocytosis: Monocytosis: Leukopenia:
Decrease the number of RBCs. Increase the number of RBCs. Increase the number of leukocytes. Increase the number of neutrophils. Increase the number of eosinophils. Increase the number of lymphocytes. Increase the number of Monocytes. Decrease the number of leukocytes.
Leukemia Definition: It is abnormal increase in the number of leukocytes especially with immature cells. Types of Leukemia: 1-Lymphocytic Leukemia. 2-Myelocytic or Granulocytic Leukemia.
Differences between Lymphocytic and Granulocytic Leukemia
Criterion
Lymphocytic
Myelocytic
Cell-types
Increase lymphocytes lymphoblasts
Increase granulocytes myelocytes myeloblasts
Spleen
Enlarged or not
L.ns.
Enlarged with grayish red color Yellowish and grayish (not pinkish)
Enlarged with dark red color and ruptured Not involved
Bone marrow
Liver, kidneys, Lesser affected than lungs the granulocytic
Serous memb.
grayish or pinkish Focal or diffuse neoplastic swelling, greenish in color, fatty changes in liver
Petechial hemorrhages