Marrow involvement with T cell lymphoma initially presenting as abnormal myelopoiesis.

Three cases of T cell lymphoma affecting the marrow, in which initial bone marrow appearances were misleading, occurred. In each case the initial clinical presentation was related to cytopenia, but the marrow abnormalities at this time suggested an abnormal myeloid proliferative state, with no evidence of a malignant lymphoid proliferation. Later in the course of the disease, however, the characteristic pattern of marrow infiltration by mature post-thymic T cells became evident. The consequent delay (two to 36 months) in diagnosis was noted.