Variations in the nuclear‐cytoplasmic ratio during epithelial differentiation in experimental oral carcinogenesis

Abstract

An increased nuclear‐cyloplasmic ratio is one of the cytological features of epithelial alypia taken into account when the histopathologist subjectively assesses whether an epithelial lesion is likely to become malignant. The present work evaluates this ratio ultrastructurally in the DMBA‐treated hamster cheek pouch model with a view to assessing whether alterations of this feature represent a valid indicator of malignant transformation. Following DMBA treatment, lesions obtained were assigned to three defined histopathological categories, namely epithelial hyperplasia, epithelial dysplasia and squamous cell carcinoma. Untreated pouches served as controls. Electron micrographs were obtained of basal, spinous and granular layer cells from each of these categories and the N/C ratio was evaluated using stereological point counting techniques. The results indicated that progressive decreases in the ratio occurred in all pathological stages during differentiation (i.e., between basal and granular cells). During carcinogenesis there was a tendency for the ratios to decrease in each cell layer but significant differences were not detected between normal and premalignant lesions.

Preliminary assessment of the epithelial nuclear‐cytoplasmic ratio and nuclear volume density in human palatal lesions

“…This observation is confirmed by the present study ( Table 4). In spinous cells, PARs are only elevated in malignant lesions (Table 5) and a similar finding, with a PAR value of 1.62, was detected in chemically induced hamster cheek pouch carcinomas (20).…”

“…perplasias, inflammatory lesions, hyperkeratoses, squamous cell papillomas, lichen planus, leukplakias with dysplasia, and for dysplasias from the edge of malignant lesions as well as in malignant lesions themselves. Although statistically significant increases in both N/C and VVN have been detected in hamster cheek pouch dysplastic and malignant lesions (14,20), PARs for basal cells in oral epithelial lesions calculated from published reports (20,26) reveal a range of values from 0.83-1.15. There seems to be no correlation between values for benign lesions and those lesions with increased malignant potential.…”

Histometric study of leukoplakia, lichen planus and carcinoma in situ of oral mucosa

“…Subjective methods of microscopic examination utilizing classic histopathologic criteria, have been shown to be inadequate (Franklin ct al. 1980, White & Gohari 1981. Histomctric techniques quantifying several histologic parameters in the epitheliutn (Franklin & Craig 1978, Weibel et al 1966, could provide an objective method of differentiating these lesions.…”

Estimating volumes from common carp hepatocytes using design‐based stereology and examining correlations with profile areas: Revisiting a nutritional assay and unveiling guidelines to microscopists

“…Importantly, the only way N / C a and N /Cell a could be computed based on areas would be by randomly sampling all sectioned hepatocytes, no matter the nucleus presence in the sectioned profile, and then estimate the relation between all areas. This strategy to unbiasedly estimate N / C ratios was already used in human pathology (Carvalho, Saldiva, Takagaki, & Capelozzi, ; White & Gohari, ).…”