A quantitative cytopathologic study of early squamous cell carcinoma of the bronchus

Abstract

Sputum cytologic findings of twenty-five cases of resected early squamous cell carcinoma were analyzed quantitatively. All the cases were radiographically occult. Four cases were in situ carcinoma and twenty-one cases showed limited invasion within the bronchial wall. Cytomorphological findings of in situ and early invasive squamous cell carcinoma were compared with those of frankly invasive carcinoma and borderline cases (i.e. sputum in which cancer was cytologically suspected, but for which no cancer was detected after intensive examinations).
Cytomorphological differences among these groups were demonstrated to some extent. Cellular atypism of early squamous cell carcinoma was generally less bizarre than those of frankly invasive carcinoma, and it was sometimes difficult to discriminate these abnormal cells from severe atypical squamous metaplastic cells. These abnormal squamous cells were characterized by the predominant feature of keratinization ranging from small round or oval orangeophilic cells with relatively high N/C ratio to large polygonal slightly orangeophilic cells. Multinucleations were frequently observed.
The essential factors affecting these findings are various degrees of cellular differentiation toward the bronchial surface, surface maturation and abnormal mitoses.