Recognition of preleukemia.

Preleukemia, which can only be diagnosed retrospectively with certainty, presents multiple findings and clinical data which contribute to a pattern recognition process. The development of cytogenetic and marrow culture studies has not only provided additional criteria for diagnosis but also better indices of prognosis. Preleukemia can be considered to be an early expression of neoplastic disease that merges into smoldering leukemia and progresses to acute leukemia. However, in the prospective evaluation of a patient, the term hemopoietic dysplasia should be used since there are no criteria to predict the outcome in an individual case.