Two malignant lymphomas arising from the palatine tonsil were investigated with gene rearrangement using Southern blot hybridization (SBH) and polymerase chain reaction (PCR) techniques. Both were non-Hodgkin's lymphomas (NHLs) with B-cell phenotype.
In Case 1, biopsy of the palatine tonsil could not be diagnosed histologically, but NHL was confirmed by cervical lymph node examination. The palatine tonsil and lymph node tissues both showed immunoglobulin (Ig) heavy chain gene rearrangement in SBH and PCR tests.
Palatine tonsil tissue before therapy in Case 2 showed Ig heavy chain gene rearrangement in SBH and PCR examinations. After chemotherapy, gene rearrangement was detected by PCR, but not by SBH. In addition, immunohistological examinations showed that the tumor cells were decreased and infiltrating T cells were markedly increased by chemotherapy.
In conclusion, gene rearrangement examinations of NHL tissues were useful in the diagnosis and in the assessment of the effectiveness of chemotherapy. In Case 2, it was thought that the genes of the tumor cells were destroyed by chemotherapy, so gene rearrangement was not detected by SBH.
