Evaluation of exfoliative cytology in the diagnosis of oral premalignant and malignant lesions: A cytomorphometric analysis

Abstract

Background: Many oral squamous cell carcinomas (OSCCs) arise within regions that previously

had premalignant lesion. Early diagnosis and prompt treatment of premalignant lesions offers the

best hope of improving the prognosis in patients with OSCC. Exfoliative cytology is a simple and

non-invasive diagnostic technique that could be used for early detection of oral premalignant

and malignant lesions. This study was undertaken to evaluate the quantitative changes in nuclear

area (NA), cytoplasmic area (CA) and nuclear-to-cytoplasmic ratio (NA/CA) in cytological

buccal smears of oral leukoplakia with dysplasia (OLD) and OSCC patients while comparing

with normal healthy mucosa.

Materials and Methods: A quantitative study was conducted over 90 subjects including

30 cases each of OLD, OSCC and clinically normal oral mucosa. The smears obtained

were stained with Papanicolaou (PAP) stain and cytomorphological assessment of the

keratinocytes was carried out. The statistical tools included arithmetic mean, standard deviation,

Chi-square test, analysis of variance, Tukey multiple comparison. P < 0.001 was considered

as signifi cant.

Results: The mean NA of keratinocytes in the normal mucosa was 65.47 ± 4.77 μm2 while for

OLD it was 107.97 ± 5.44 μm2 and 139.02 ± 8.10 μm2 for that of OSCC. The differences show a

statistically signifi cant increment in NA (P < 0.001). There was signifi cant reduction (P < 0.001) in

the CA of keratinocytes from OSCC when compared with those from smears of OLD and normal

mucosa with the values of 1535.80 ± 79.38 μm2, 1078.51 ± 56.65 μm2 and 769.70 ± 38.77 μm2

respectively. The NA/CA ratio in the smears from normal oral mucosa, OLD and OSCC showed a

mean value of 0.043 ± 0.004, 0.100 ± 0.008, 0.181 ± 0.015 respectively with a signifi cant difference

among the groups (P < 0.001).

Conclusion: Evaluation of nuclear and CA of keratinocytes by cytomorphometry can serve as

a useful adjunct in the diagnosis and prognosis of a dysplastic lesion which may lead to OSCC.

Key Words: Cytomorphometry, dysplasia, exfoliative cytology, oral leukoplakia, oral squamous cell carcinoma