Presence of human papillomavirus type 6f in tonsillar condyloma acuminatum and clinically normal tonsillar mucosa

An attempt was made to detect human papillomavirus (HPV) in 8 cases of oral papilloma by Southern blot hybridization. HPV type 6 was identified in a case of tonsillar condyloma acuminatum, but neither HPV type 6 nor 11 was found in the 7 other cases of squamous papilloma. The hybridization pattern of the HPV type 6 DNA after digestion with restriction enzymes revealed that the HPV was of the 6f subtype. DNA samples isolated from the condyloma acuminatum, 3 peripheral specimens of clinically normal tonsillar mucosa, a swab sample and saliva from the male patient with this tonsillar condyloma acuminatum were examined further by polymerase chain reaction (PCR). HPV type 6 DNA was detected in the tonsillar condyloma acuminatum and the 3 specimens of clinically normal tonsillar mucosa, but no HPV type 6 DNA was detectable in the normal tonsillar mucosa by Southern blot hybridization using a whole HPV DNA probe. The presence of a small amount of HPV in clinically normal tissue detectable only by PCR suggests latent infection of peripheral tissues with HPV produced from the condyloma acuminatum. Although HPV type 6 DNA was not detectable in the swab and saliva samples of this single case, further study is necessary for the clinical application of preoperative virological diagnosis by PCR using these samples.