Spontaneous regression of chemotherapy-refractory non-Hodgkin's lymphoma preceding the development of secondary leukaemia.

In this report a rare case of spontaneous regression of a long-standing chemotherapy resistant low grade non-Hodgkin's lymphoma (NHL) of follicular small cleaved cell type is described. Extensive bulky lymphadenopathy substantially resolved, 7 months before the diagnosis of acute myelomonocytic leukaemia was established, in the absence of further treatment. It is possible that in this case the mutagenic effects of alkylating agents given during the course of the NHL reprogrammed lineage commitment in an early progenitor cell, deviating potential B-lineage cells along the myelomonocytic pathway.