A total of 585 Sprague-Dawley(SD) rats were examined to observe incidence rates. pathologic characteristics, morphological classifications of the spontaneous tumors in the hematopoietic organs of tissues. The tumors were observed gross pathologically and histopathologically.
The resulted obtained were as follows:
1. The incidence rate of hematopoietic tumors was 2.56 percent(15 cases/585 rats).
2. Tumors observed in hematopoietic organs and tissues were classified by morphological features into lymphoma, histiocytic sarcoma and granulocytic leukemia.
3. The incidence rate of lymphoma was 1.2 percent. The lymphoma was classified into lymphoblastic lymphoma and follicular center cell lymphoma. The highest incidence rate of lymphoma was lymphoblastic lymphoma. The manomarphic immature lymphoid cells of lymphoblastic lymphoma were observed in the spleen, liver and lymph node.
4. The incidence rate of histiocytic sarcoma was 0.8 percent. The involved organs were liver, lung and subcutis.
5. The incidence of granulocyte leukemia was 0.5 percent. The tumor cells were distributed in the lung, spleen, bone marrow, kidney and liver.
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