Low-grade lymphoma following intensive treatment of large-cell lymphoma.

Progression of a low-grade non-Hodgkin's lymphoma into a more aggressive histologic pattern is a well-described phenomenon. The converse phenomenon, often called downgrading, is much less frequent. We report 2 patients in whom relapse with an indolent lymphoma was noted after chemotherapy for higher-grade disease. Other previously reported cases are reviewed. The implications for appropriate management and pathogenesis are discussed.