Fluorescence microscopy utilizing acridine orange in oral cytodiagnosis

Adjunctive diagnostic techniques for oral lesions of unknown malignant potential: Systematic review with meta-analysis

BACKGROUND

The purpose of this study was to critically review the published evidence concerning adjunctive diagnostic techniques in the diagnosis of oral lesions of unknown malignant potential.

METHODS

We conducted a systematic literature review with meta-analysis using PubMed to search for articles published from June 1993 through June 2013 to identify prospective studies evaluating any diagnostic method, with tissue biopsy confirmation, in clinically evident oral lesions of unknown malignant potential. Aggregate weighted totals and SEs for true, false-positive, false-negative, and inadequate results were calculated and compared among subgroups.

RESULTS

Forty-eight articles satisfying inclusion criteria were identified. Twenty-five were included in quantitative synthesis.

CONCLUSION

Oral cytology holds higher diagnostic value than specialist's oral examination, which holds higher value than in vivo toluidine blue staining. This study does not support the use of computer-aided or liquid-based cytology. Future studies should be designed to test multiple methods in the same patient population to allow direct comparison among various techniques.

Cytogenetic biomonitoring in petrol station attendants: A micronucleus study

Background:

Benzene, which is a major organic product, on chronic exposure can result in many malignant disorders, and therefore exposure to gasoline vapors is classified by the International Agency for Research of Cancer as possible carcinogenic to humans. Petrol station attendants are chronically exposed to petroleum derivatives through inhalation of petrol during vehicle refuelling.

Aim:

This study is aimed to investigate cytogenotoxic damage in exfoliated buccal cells obtained from petrol station workers and control subjects using micronucleus (MN) test.

Materials and Methods:

This study was carried out on 30 petrol station attendants working at different petrol stations located in Indore. The control group consisted of 30 healthy subjects who were not exposed to benzene. Buccal cell samples were collected at the end of the work shift. Slides were stained and were evaluated to determine the MN frequencies. Exposure monitoring was performed by the detection of phenol excreted in the urine. Urinary phenol measurements were performed following the colorimetric quantitative determination method of Yamaguchi and Hayashi.

Results:

Variations in MN frequencies were seen in control and petrol bunk attendants.

Conclusion:

The MN test in exfoliated epithelial cells seems to be a useful biomarker of occupational exposure to genotoxic chemicals. Phenol is the principal metabolite of benzene. Therefore, phenol concentration in the urine of exposed workers can be used as a biomarker of external exposure.

Oral cytology revisited

During the last decade, oral cytology has once again become the focus of scientific research. This new interest is due to the introduction of a cytobrush for cell collection as well as a computer-assisted analysis (Oral CDx). Although promising, the sensitivity and specificity of conventional oral brush cytology remains limited. To circumvent the problems and improve the accuracy, various adjunctive analytical methods have been attempted. DNA analysis, immunocytochemical and molecular analysis are suggested methodological cytology approaches to improve the validity of oral brush cytology. An increase in sensitivity (up to 100%) and specificity (up to 100%) of oral brush biopsy has been reported on localized pre-malignant and malignant lesions. Oral brush biopsy probably will not replace histopathology in the definitive diagnosis of oral cancer, but it might be valuable for the prevention of misdiagnosis of clinically doubtful oral lesions and for the monitoring of lesions that might proceed on to oral cancer.

[Oral cytology: historical development, current status, and perspectives]

Oral cytology has aroused new interest caused by introduction of the cytobrush as a sampling device and the use of additional analytical methods. By brushing it is possible to reach deeper layers of the oral mucosa where squamous intraepithelial neoplasia (SIN) begins. The biological potential of the oral epithelial cells obtained can be evaluated by the following additional methods: computer-assisted image analysis (OralCDx), DNA cytometry, immunohistochemistry, monolayer cytology, and molecular biological analysis. All of those methods can increase sensitivity (up to 100%) and specificity (up to 100%) of oral brush biopsy. Nevertheless, there are reports that oral epithelial carcinomas were not identified. No comparative study exists allowing conclusions to be drawn about the value of the single methods. Immunocytochemistry with commercial antibodies against laminin-5 is generally available and methodologically easy. Oral brush biopsy as a non invasive diagnostic method can be useful for the early detection of oral mucosal lesions. Positive findings or progression of the lesion despite negative findings are indications to refer the patient to a specialized clinic where a surgical biopsy should be performed, followed by histopathological analysis. Histopathology remains the gold standard for the definitive diagnosis of oral malignant lesions.