[Malignant lymphoma displaying rearrangements of both immunoglobulin and T-cell receptor genes].

A 65-year-old male was admitted to our hospital due to recurred malignant lymphoma of left tonsil origin. Studies using flow cytometry on mononuclear cells in peripheral blood revealed the appearance of intermediate B cells, and examinations on gastrointestinal tract showed diffuse infiltration of medium-sized lymphoid cells into stomach and colon, that had the same phenotype as tumor cells in peripheral blood. They suggested leukemic change and gastrointestinal tract infiltration of malignant lymphoma. Southern blot analysis revealed T-cell receptor beta-chain gene rearrangement as well as immunoglobulin gene rearrangement. Analysis by histo in situ hybridization on infiltrated gastric mucosa specimen showed diffuse expression of immunoglobulin mRNA in tumor cells, but no message of T-cell receptor beta-chain gene. Northern blot analysis showed the same result. It suggests that in this case, the rearrangement of T-cell receptor beta-chain gene is ineffective rearrangement without transcription to mRNA.