Lymphoproliferative lesions in BB Wistar rats

Fifteen percent of long-term diabetic BB Wistar rats developed abdominal B cell lymphoproliferative lesions which ranged from minute mesenteric aggregates of plasma cells and lymphocytes to malignant lymphoma with features of immunoblastic sarcoma or plasma-cell lymphoma. Lymph nodes in younger BB Wistar rats, both diabetic and nondiabetic, demonstrated variable degrees, often extensive, of paracortical and medullary replacement by plasmacytoid lymphocytes and/or plasma cells. This study documents morphologic abnormalities in lymph nodes of BB Wistar rats, thus providing additional evidence of altered immunity in this model.