Biological monitoring of chemical exposure in nickel workers by imaging cytometry (ICM) of nasal smears.

Highly sensitive and inexpensive methods that are not time consuming are desirable for monitoring the workplace environment for the detection of cytotoxic hazards, particularly cancerous risks. It is possible to detect precancerous and cancerous lesions in samples taken by brushing the nose, but the cytological diagnoses can be affected by an inability to obtain representative smears from the sometimes very small focal lesions, and uncertainties in the subjective interpretation of suspicious cells when these are small in number. In an attempt to improve diagnosis we applied imaging cytometry (ICM) and tested the concept of malignancy-associated changes (MAC) in routinely Papanicolaou-stained smears. Cells of non-goblet type that visually appeared normal were selected from nickel workers with and without dysplastic lesions of the nasal mucosa. A set of nuclear features was measured by ICM and used for discriminant analysis. We were able to differentiate between workers with non-dysplastic normal and suspicious mucosa smears and those with dysplastic lesions. Unexpectedly, it was found possible to distinguish between workers in the roasting/smelting and the electrolysis departments, who were exposed to different carcinogenic nickel compounds. A further surprising finding was the possibility to distinguish smokers and non-smokers among the nickel workers.

How often is dysplasia diagnosed by biopsy or smear examination? Application of a maximum likelihood based method to the assessment of detection rates in the nasal mucosa of nickel workers.

In view of the known increased risk of nasal carcinoma and the high prevalence of dysplastic lesions of the nasal mucosa among nickel workers, regular screening for the existence of possibly precancerous dysplastic lesions is offered to workers in a Norwegian nickel refinery. Unfortunately, available sampling techniques do not allow the identification of all subjects in whom dysplastic changes are present. Independent histological and cytological (brush cytology) diagnoses, obtained for each of a group of 90 workers, have been used to estimate, by a maximum likelihood method, the probabilities that existing dysplastic lesions will be detected by each of these two screening methods. In the group studied, cytology performed rather less well than histology in unambiguously detecting dysplasia. However, when cytological specimens showing irregular (possibly dysplastic) epithelial cells were grouped with those showing clear dysplastic changes, detection probabilities were estimated at 0.52 by histology and 0.57 by cytology. Detection probabilities were estimated to be higher among subjects with a previously known history of dysplasia, particularly by histology (P < 0.01), probably due to larger dysplastic areas. In view of both its greater facility and speed of sampling, and its greater acceptability, brush cytology may be preferable to biopsy sampling for the screening of large numbers of workers at risk.

Development of brush cytology for detection of metaplastic and dysplastic nasal mucosa lesions. A preliminary report.

Nickel workers and wood workers have an increased incidence of carcinoma and of lesions of the nasal mucosa regarded as precancerous, i.e. dysplasia. This preliminary study demonstrates how metaplastic and dysplastic changes of the nasal epithelium may be diagnosed independently from cytological smears and from histological sections of samples from the same middle nasal turbinate. The sampling technique described yielded excellent material for cytological diagnosis and was also suitable for detailed cell surface characterization by scanning electron microscopy (SEM). Exfoliative cytology was found to be a reliable means of detecting preneoplastic changes in the nasal mucosa of individuals in selected risk groups. The sampling procedure causes less discomfort to the subjects and requires fewer resources than biopsy procedures.