Highly aggressive lymphomas in adults.

Highly aggressive lymphomas are relatively uncommon in adults, comprising approximately 4% to 5% of all non-Hodgkin lymphomas in the United States and Western Europe. The designation of "highly aggressive" is generally restricted to precursor T-cell and B-cell lymphoblastic lymphoma/leukemia and Burkitt's lymphoma/leukemia. Treatment strategies for lymphoblastic lymphoma and Burkitt's lymphoma include complex, highly intensive combination chemotherapy regimens, which may be curative. As with other subtypes of NHL, emerging data from gene-expression profiling and related techniques are helping to define these entities more precisely and identify potential new rational therapeutic targets.