A spontaneous lymphoblastic lymphoma in a guinea-pig.

The exceptional carcinoresistance of guinea-pigs is well known and only a few cases of spontaneous leukaemia and several very rare cases of lymphoma have been reported in the literature. A spontaneous malignant tumor in an old male hybrid guinea-pig is described. The monomorphous aspect of the tumour, the cellular cohesiveness, the "starry-sky" pattern and the immunocytological characterization of tumour cells as B lymphocytes bearing IgM, lead to describe this tumour as a probable spontaneous Burkitt-type malignant lymphoblastic lymphoma.