T-cell prolymphocytic leukemia is a rare post-thymic lymphoid disorder, which 
has distinctive clinical, morphologic, immunophenotypic and cytogenetic 
features. It has previously been associated with an aggressive course, poor 
response to conventional chemotherapy and a short median survival. Treatment 
with purine analogs and the monoclonal antibody alemtuzumab has resulted in 
significantly higher response rates and increased survival. However, responses 
are transient and allogeneic hematopoietic progenitor-cell transplantation 
remains the only potential curative option. The proportion of patients eligible 
for transplant is low, owing to the older age group of patients, and 
nonmyeloablative transplantation is a promising alternative that needs to be 
explored.