Mast cell tumours in CD-1 mice.

A survey of the occurrence of mast cell tumours in CD-1 mice (Caesarian derived) recorded nine tumours in 24352 mice used for carcinogenicity studies over a period of six years (1984-1989). All except one appeared as multi centric tumours. Three of the mice had deposits only in the bone marrow, one of those cases was associated with intestinal adenocarcinoma and harderian gland adenoma. Case four had deposits in lung, thymus, lymph nodes, liver, spleen and kidney and occurred in association with pulmonary adenocarcinoma and pleomorphic lymphoma. Case five showed the tumour deposits in mesenteric lymph nodes and liver. Case six showed deposits of the tumour in lung, liver, kidney and bone marrow and in this case there was also a cutaneous fibrosarcoma. Case seven was diagnosed as mast cell leukaemia. Case eight was a subcutaneous tumour, case nine showed subcutaneous deposits and deposits in lungs, lymph nodes, liver, spleen and bone marrow.