Establishing the accuracy of a new and cheaper sample collection tool: Oral cytology versus oral histopathology

Analysis of false-negatives in exfoliative cytology in oral potentially malignant disorders: A retrospective cohort study

INTRODUCTION

Keratinized lesions have been a conceivable false-negative (FN) factor in oral exfoliative cytology (OEC); however, other factors are poorly analyzed. In this study, we aimed to identify the factors influencing the accuracy of OEC and FNs focusing on the lesion characteristics, patient background, and surgeon factors in oral potentially malignant disorders (OPMD).

MATERIAL AND METHODS

We retrospectively studied 44 patients who underwent both OEC and histopathological diagnosis. Sensitivity, specificity, FN rate, false-positive (FP) rate, and prevalence of both methods were compared. Similarly, accuracy indices were compared among clinical diagnosis groups (leukoplakia vs. other diagnosis). The association between patient and surgeon-related factors influencing FN OEC results were investigated using Fisher's exact test and a multiple logistic regression analysis.

RESULTS

Overall, the sensitivity; specificity; and FN, FP, and prevalence rates of OEC were 31.8%, 82.1%, and 68.8%, 17.9%, and 36.4%, respectively. Leukoplakia was significantly more common in clinical diagnosis (P = 0.007) with sensitivity, specificity, and FN rates of 20.0%, 95.2%, and 80.0%, respectively. Contrarily, non-keratinized lesions had sensitivity, specificity, and FN of 83.3%, 85.7%, and 16.7%, respectively. In the prevalent group, leukoplakia and anucleate squamous cells were significantly associated with FN cases (P = 0.013, P = 0.050). On multivariate analysis in OEC negative patients, age ≤64 (P = 0.050) and location on the tongue (P = 0.047) was independently associated with FNs.

CONCLUSION

FN of OEC was conceivable to be due to poor deep-seated cell sampling, which was associated with leukoplakia, age, and location. Therefore, these factors may be considered in the evaluation of OEC results.

Comparison of transepithelial cytology and histopathology in the diagnosis of potentially malignant and malignant lesions of the oral mucosa

Background/Aim: The objective of the study was to compare cytological diagnoses using transepithelial cytology (oral brush biopsy) with histopathological diagnoses obtained by incisional biopsy in patients with benign lesions, oral potentially malignant disorders and oral squamous cell carcinoma. Material and Methods: The study included 57 patients. Brush biopsy was performed after local anaesthesia administration using the cervical brush. It was immediately followed by an incisional biopsy. Modified Bethesda System was used for cytological analysis and correlated with histopathological diagnoses according to intraepithelial neoplasia. Results: Good agreement was shown between cytological and histopathological diagnosis (kappa = 0.791). The sensitivity of the study was 92.85%, specificity 100%, positive predictive value (PPV) was 100% and negative predictive value (NPV) 93.54%. Conclusions: Oral brush biopsy, which allows the collection of epithelial cells of all layers can provide fast, precise and efficient cytological results which are in good agreement with the 'gold standard'-incisional biopsy followed by histopathology.

The potential impact of vegetarian diet on the oral mucosa: A preliminary cytopathological study

BACKGROUND/PURPOSE

Actually, many individuals have opted for the vegetarian diet. The objective of this study was to evaluate the impact of the vegetarian diet on the oral epithelium through cytopathology.

METHODS

Oral smears of the tongue and buccal mucosa of 60 adult subjects (30 vegetarians and 30 controls) were collected. Smears were analyzed morphologically and for three morphometric variables: nucleus area (NA), cytoplasm area (CA) and nucleus/cytoplasm ratio.

RESULTS

Vegetarians were classified as ovolactovegetarian (53.3%), vegans (30%) and strict vegetarians (16.7%). The NA and CA of the epithelial cells of vegetarian individuals were smaller when compared to controls both in the region of the buccal mucosa and tongue. However, there was no statistically significant difference according to the Student's t-test. For the NA/CA ratio, cells in the oral mucosa region were larger for vegetarians compared to controls. For the tongue, both groups had the same value and the Mann-Whitney U test confirmed that there is no difference between the groups for this cytomorphometric variable.

RESULTS

Vegan individuals had a smaller (but not larger) area of CA when compared to controls for the tongue (vegan = 2604.2 ± 179.2 versus control = 3256.7 ± 463.8 p = 0.013). Most smears showed normal epithelial cells and some individuals had changes of an inflammatory nature, mainly in the tongue.

CONCLUSION

Despite the small sample size, the results of this study raise the hypothesis that the vegetarian diet (especially the vegan diet) can compromise the thickness of the oral epithelium of the tongue.