Spontaneous development of neoplasms in severe combined immunodeficient mice

Severe combined immunodeficient (SCID) mice lack functional T and B cells. This renders them useful for implantation of human cells. The absence of immune cells, however, makes severe combined immunodeficient mice highly susceptible to infections and spontaneous development of malignancies; 2 of 114 CB17/Icr-Prkdcscid/IcrIcoCrl severe combined immunodeficient mice aged 9 and 10 months developed spontaneous acute leukaemia and thymic lymphoma. The differential diagnosis of such an atypical lymphoid infiltrate includes ‘leaky’ severe combined immunodeficient mice, thymic lymphoma and acute leukaemia. Until this time, the link between the development of neoplasms in severe combined immunodeficient mice and the mutation remains unclear.