Karyometry of nuclear phenotypes in cutaneous squamous cell cancer.

Objective: To establish the karyometric characteristics of the two main nuclear phenotypes in cutaneous squamous cell cancer (cSCC) lesions.

Study design: The clinical materials comprised 75 cases of cSCC, 38 with aggressive lesions and 37 with nonaggressive lesions. High-resolution images of 100 nuclei per case were recorded. Data were partitioned into four subgroups covering the range of lesion progression. Four discriminant functions were derived to distinguish aggressive from nonaggressive lesions. The most typical nuclei from the phenotype predominant in aggressive lesions and nonaggressive lesions were separated out by thresholding on the discriminant function score axes. For these homogeneous sets of nuclei the karyometric features were computed.

Results: The nuclear populations in cSCC lesions are a very heterogeneous set. There are two axes of dispersion, along the line of lesion progression and between aggressive and nonaggressive lesions. The analysis faces the difficulty that lesions from both diagnostic categories contain nuclei of the same two phenotypes with the difference between categories consisting only of differences in proportion of the two phenotypes.

Conclusion: The nuclei of the aggressive phenotype I and nonaggressive phenotype II have substantially different chromatin patterns and can be distinguished with > 90% correct recognition rate.