Exfoliative-cytologic diagnosis of basal-cell carcinoma, with the use of DNA image cytometry as a diagnostic aid.

Eighty-four skin lesions clinically suspected of being basal-cell carcinomas were investigated by exfoliative cytology. Specific criteria were found for the cytologic diagnosis of basal-cell carcinoma. All 37 cases of basal-cell carcinoma were correctly classified cytologically and could be differentiated from the 8 cases of squamous-cell carcinoma. There were no false-positive or false-negative diagnoses. Insufficient cellular material was obtained in 17% of the cases. The technique for collecting exfoliated epidermal cells with a new swab is described. DNA image cytometry was used as a diagnostic aid in doubtful cases. DNA image cytometry showed that 83% of the basal-cell carcinomas had an aneuploid nuclear DNA content.