Relapse with nodular lymphoma following combination chemotherapy for diffuse non-Hodgkin's lymphoma.

Histologic conversion within the non-Hodgkin's lymphomas is a well-described phenomenon. Conversion from an indolent to that of a more aggressive histologic pattern is the most frequently noted form of this variability. We describe two patients in whom relapse with an indolent nodular lymphoma was noted after combination chemotherapy for diffuse disease. Implications for diagnostic evaluation and therapy as well as the pathogenesis of this unique form of conversion are discussed.