[New diagnostic methods in non-Hodgkin lymphoma]

We describe five patients with non-Hodgkin's lymphoma (NHL) in which immunohistochemical investigation (IH) and polymerase chain reaction (PCR) were important for diagnosis and choice of treatment. One patient got the diagnosis follicular NHL after PCR showed t(14;18) in a fine needle biopsy from a tumour in the abdomen. Two small and partly traumatized biopsies from two patients were diagnosed as low grade NHL of B-cell type after PCR showed monoclonality for B-lymphocytes and IH showed B-cell phenotype and low proliferation rate. Biopsy from another patient showed positive immunohistochemical reaction for cyclin D1 and t(11;14) by PCR compatible with mantel cell lymphoma. One patient was diagnosed with high grade NHL of T-cell type after IH showed positive reaction for T-cell markers and high proliferation rate, and PCR showed monoclonality for T-lymphocytes. These cases demonstrate that IH and PCR can often benefit patients with NHL. The new methods contribute to enhanced diagnostic security and precision in subclassification and make possible the use of small biopsies which save the patients from major surgery for diagnostic purposes.