FREQUENT P53 MUTATIONS AT DIPYRIMIDINE SITES IN PATIENTS WITH PYOTHORAX-ASSOCIATED LYMPHOMA

A high incidence of non-Hodgkin's lymphoma of the pleural cavity has d eveloped in Japanese patients with long-standing pyothorax (38 years o n average) resulting from artificial pneumothorax for the treatment of pulmonary tuberculosis or tuberculous pleuritis. Patients with pyotho rax-associated lymphoma (PAL) have long been exposed to antituberculou s drugs, antibiotics, bacterial or viral products, and frequent diagno stic radiation for the confirmation of pneumothorax and pyothorax. We analyzed p53 mutations on paraffin-embedded specimens from 21 patients with PAL by PCR-single-strand conformational polymorphism followed by direct sequencing, An unusually high frequency of p53 mutations (14 o f 21 cases, 67%) was detected in the PAL specimens, and mutations cons isted of 13 nucleotide substitutions and 1 deletion. Furthermore, 10 o f 13 substitutions (77%) occurred at dipyrimidine sites (CC:GG to CT:G A substitution). Such specificity has not been reported, except for so lar Light-related skin canter and AIDS-related lymphoma in some parts. An UV Light mimetic agent may be produced in the long history of chro nic inflammation in tuberculosis or immunodeficient patients.