Spontaneous lymphoid neoplasia in the koala (Phascolarctos cinereus).

Thirteen cases of lymphoid neoplasia were examined in koalas from New South Wales and Queensland. Haematological and biochemical data were collected from 2 cases while all were subjected to detailed necropsies. Affected koalas were adults of both sexes and the disease had a variable time course. The 2 koalas examined haematologically were leukaemic. On a morphological basis, 5 cases were classified as multicentric, 7 cases as abdominal (but not necessarily with alimentary tract involvement) and one case as solitary. In most cases, the neoplastic cells appeared to be either lymphoblasts or prolymphocytes.