Pathologic Report of 29 Necropsies on Dogs with Mastocytoma

Abstract

At necropsy 28 of 29 dogs with cutaneous mastocytoma had internal accumulations of mast cells in various organs. The order of decreasing incidence in these organs was: regional lymph nodes, spleen, liver, bone marrow, kidneys, lungs, and heart. No correlation was obvious between the size of the external lesions and the extent of internal involvement. A good correlation existed between the degree of anaplasia of the initial external tumor and the extent of subsequent internal involvement. Other significant lesions observed in these dogs included a diffuse plasmacytosis and a chronic focal glomerulitis. The distribution of neoplastic mast cells in some dogs inferred a multicentric origin. The possibility of an autoimmune reaction in these dogs is briefly discussed.