Morphologic classification and correlation of incidence of hyperplastic and neoplastic hematopoietic lesions in mice with age.

Information from the NCTR control pathology data base was examined to morphologically classify and correlate the incidence off hyperplastic and neoplastic hematopoietic lesions with age in over 15,000 male and female mice of a variety of strains. Hyperplasia affected lymphoid and reticular cells, erythropoietic and granulopoietic cells, mast cells, plasma cells and megakaryocytes. Neoplastic lesions included lymphocytic lymphoma, mixed cell lymphoma, histiocytic lymphoma, granulocytic leukemia, plasma cell neoplasms and mast cell neoplasms. Most hyperplastic and neoplastic hematopoietic lesions increased wtih age and most were slightly more common in the female than in the male mice.