The Cytological Findings of Oral Inflammatory Lesions, Lichen Planus and Leukoplakia Coexisted with and without Candida : With Special Reference to Clinical, Histopathological, Immunohistochemical and Flow Cytometrical Analyses

To evaluate the coexistence of Candida in potentially malignant oral mucosal lesions : inflammatory lesions without features of leukoplakia and lichen planus (IL), lichen planus and leukoplakia using exfoliative cytology (EC). This was evaluated and compared with clinical findings, histopathology, immunohistochemistry and flow cytometrical analysis (FCMA). In order to assess the coexistence of Candida with inflammation, lichen planus and leukoplakia, the smears were taken for Papanicolaou staining. To improve accuracy, PAS staining was performed. Forty-nine cases of smears with biopsy specimens were used for comparative study of EC and histopathology. Also, the immunohistochemical activity of these cases was measured using p53, Ki-67 and COX-2. As for FCMA, the D.I. and P.I. were calculated for all EC smears. One hundred and seventy-five cases of EC smears were obtained from 40 normal tissue samples (control), inflammatory lesions (IL) ｢42｣, lichen planus ｢49｣ and leukoplakia ｢44｣. Clinical findings revealed the presence of whitish patches with erythema in lichen planus and leukoplakia, except for IL where erythema was present in all cases. Overall, 70 cases (40.0%) were confirmed by PAS to contain Candida in the smear : IL ｢20｣, lichen planus ｢24｣, and leukoplakia ｢26｣ with the coexistence rate of 47.6%, 49.0% and 59.1%, respectively. The cytological atypia in these cases was stronger than those without Candida, but was different from dysplastic change. Forty-nine cases (28.0%) were available for immunohistochemical investigation where both smear and histopathology specimens were taken. The mutation of p53, cell proliferation Ki-67 and inflammatory index of COX-2 ; related with prostaglandlins, were also elevated in cases coexisted with Candida. FCMA showed higher aneuploidy (D.I.) in cases with Candida : 1.8 for IL, 2.1 for lichen planus and 2.2 for leukoplakia, respectively. Those without Candida were 1.5, 1.9 and 2.0, respectively. The P.I. also showed the same tendency. Generally, Candida coexisted with these lesions found in Papanicolaou and PAS stainings showed an increased cytological atypia. Immunohistochemical results showed higher positive reaction of p53, Ki-67 and COX-2 in Candida infected diseases than those without Candida. The results indicated a strong relationship with the FCM findings. The study concluded the DNA alterations in cases coexisted with Candida was likely to be considered as irritative factor or promoter of dysplastic changes. The higher aneuploidy and proliferative index, and the immunohistochemical results gave significant indications that candidal infection may disturb the DNA cellular content.