Oral cytology: its value and its limitations

Reliability of Cytologic Examination in the Diagnosis of Laryngeal Carcinoma

Cytologic examination has been performed as systematic surrey, with drawing by plug in direct laryngoscopy, on 96 patients with intrinsic and extrinsic laryngeal lesions and, as control, on 22 patients with oro- and rhinopharyngeal lesions. The reliability of cytologic diagnosis in relation to the type of the lesion (histologically controlled), to the site of the lesion and to the staining method is evaluated.

Quantitative Exfoliative Cytology of Abnormal Oral Mucosal Smears

In this study quantitative techniques have been applied to smears collected from the buccal mucosa and floor of the mouth. The results display an encouraging success rate for identifying premalignant and malignant lesions. ‘Intrapatient’ normal smears provide a satisfactory control for comparison with pathological smears. Early results indicate that quantitative cytology could be of great value for monitoring and follow-up of suspicious lesions and provide an excellent additional diagnostic test for detecting early oral malignancy.

An evaluation of the Shandon Papspin liquid-based oral test using a novel cytologic scoring system

OBJECTIVES

The aim of this study was to evaluate a cost-effective oral liquid-based cytology screening test, Shandon Papspin (PS).

STUDY DESIGN

We compared the diagnostic accuracy of PS with surgical biopsy in 69 patients. Transepithelial cytology specimens were obtained with the use of cervical cytobrushes. Cytology specimens were graded and scored by using a novel oral cytologic grading and scoring system.

RESULTS

Histologic diagnosis of dysplasia or malignancy was made in 51/69 cases, and cytology identified 49/51 cases, with a sensitivity of 96% and specificity of 100%. The best cutoff value for distinguishing reactive/mildly dysplastic lesions from high grade/invasive squamous cell carcinoma was determined to be a cytologic score of 3, representing a sensitivity of 95% and specificity of 96%.

CONCLUSIONS

PS appears to be an accurate and economical test for detection of high-risk dysplasias and cancers, but the real significance of this method will be its diagnostic accuracy in studies focusing strictly on lesions with a low level of clinical concern.

Avaliação do exame citopatológico como método para diagnosticar a paracoccidioidomicose crônica oral

Com o objetivo de avaliar o exame citológico esfoliativo no diagnóstico das lesões orais da paracoccidioidomicose, foram estudados oito portadores desta doença. Em todos os casos, demonstrou-se o fungo através de esfregaços citológicos corados com impregnação pela prata Gomori-Grocott. Conclui-se que a citologia esfoliativa oral é um método diagnóstico útil e válido na paracoccidioidomicose, podendo auxiliar no controle terapêutico das formas orais desta micose.

Oral malignancies associated with negative transepithelial brush biopsy

PURPOSE

This study was performed to assess the incidence of negative brush biopsy for oral lesions later demonstrated histologically to be squamous cell carcinoma.

METHODS

All diagnoses of oral squamous cell carcinoma from a university oral pathology service for the period June 2000 through March 2002 were reviewed to determine if any had previously undergone brush biopsy reported to be "negative for epithelial abnormality." Those cases identified were further investigated to determine the time lapse between brush biopsy and definitive tissue diagnosis.

RESULTS

Four cases of brush biopsy negative squamous cell carcinoma were identified from 115 total cases of malignancy (3.5%). The average time from brush biopsy to tissue diagnosis was 117.25 days (range, 5 to 292 days).

CONCLUSION

False negative reports are possible with the oral brush biopsy technique. Persistent lesions should undergo tissue biopsy for definitive diagnosis.

Direct oral microscopy and its value in diagnosing mucosal lesions: a pilot study

OBJECTIVE

Clinical examination of the oral mucosa often leads to an uncertain diagnosis, and a supplementary biopsy with a histopathologic examination of the lesion is necessary to establish a definite diagnosis. However, the site for the biopsy is a subjective choice that sometimes raises doubts about its representativeness. So far, no simple and reliable method is available for selecting the most appropriate area for biopsy.

STUDY DESIGN

In a prospective study, we performed direct oral microscopy (oral application of the colposcopy technique used in gynecology) in 35 patients with various clinical diagnoses, such as leukoplakia, oral lichenoid lesions, or suspected malignancy. First, the oral mucosa was examined with direct microscopy, and the most representative site, according to colposcopic criteria, was selected. Then, the mucosa was clinically inspected by an independent examiner. The best site for biopsy according to clinical criteria was noted, and any difference in biopsy sites was recorded. Biopsy specimens were taken from 2 of these sites.

RESULTS

Twenty-nine patients (83%) showed changes in the vascular picture on microscopy, according to the colposcopy criteria. In 14 patients (40%), the biopsy sites identified by direct oral microscopy showed more advanced histologic signs than those selected by routine clinical examination (0.01 < P </=.05). Four patients (11%) had more advanced histologic signs in the biopsy samples, as identified during routine clinical examination. In 17 patients (49%), we found no differences between the biopsy specimens.

CONCLUSION

Direct oral microscopy of mucosal lesions seems to offer advantages in selecting more representative sites for biopsy than routine clinical examination alone.

Performance of a computer simulated neural network trained to categorise normal, premalignant and malignant oral smears

The accurate detection of malignant neoplasms whilst they are still small is recognised as one of the main factors increasing chances of survival. Neural networks have many biomedical applications and they have been applied to neoplasia but their use in oral pathology has only recently been documented. The objectives of this study were to train networks to discriminate between normal and dysplastic mucosa. Each network was trained by back propagation, internal cross validation and tested on additional data. The data were derived by analysing 348 intra-oral smears and included mean nuclear and mean cytoplasmic areas of the smears measured by image analysis. A neural network differentiated between normal/non-dysplastic mucosa and dysplastic/malignant mucosa (specificity 0.82, sensitivity 0.76). These early results suggest that integrating neural networks and image analysis, as well as investigating additional criteria, could enhance automation and accuracy of smear techniques in diagnosing oral malignancy.

Comparison of planimetry and image analysis for the discrimination between normal and abnormal cells in cytological smears of suspicious lesions of the oral cavity

Light microscope analysis of cytological smears of suspicious lesions of the oral cavity is used as a method for detecting early cancer in the oral cavity. The sensitivity of this approach can be improved by quantitative analysis of the cells in the cytological smears. We have compared the efficiency of planimetry and the Vids V system of image analysis, as quantitative methods for discriminating between normal and abnormal cells in cytological smears of suspicious lesions in the oral cavity. Both methods detected an increase in nuclear area and a decrease in cytoplasmic area in abnormal epithelial cells from dysplastic lesions of increasing severity. However, image analysis was better able to discriminate between benign and malignant cells on the basis of nuclear size. Thus the Vids V system of image analysis is more appropriate than planimetry for quantitative analysis of cytological smears from the oral cavity.

Quantitative exfoliative cytology of normal oral squames: an age, site and sex-related survey

This study describes the development of quantitative cytological techniques and their application to oral smears. Nuclear and cell size has been measured and matched with age, sex and site in an attempt to produce a baseline for comparison with identical measurements carried out on pathological smears. The results displayed a significant variation in nuclear and cytoplasmic area between different sites. Nuclear size varied significantly with advancing age; however, this was not the case for cytoplasmic area. There was no significant variation in either criterion between males and females.

Quantitative exfoliative cytology of normal and abnormal oral mucosal squames: preliminary communication

Quantitative techniques have been applied to the exfoliative cytology of normal and abnormal human oral mucosal squames. This study is ongoing but early results indicate that a normal baseline for clinically normal oral squames, related to age and site, may be difficult to achieve. However, results obtained for the pathological smears suggest that these techniques may improve the diagnostic sensitivity of cytology in the management of oral cancer.