The relationship between the nuclear DNA content in smears of aspirates and the prognosis of mucoepidermoid carcinoma.

Cytophometric analysis of nuclear DNA content was performed in a series of mucoepidermoid carcinomas with an extreme difference in the clinical course, which was observed during a follow-up period of 6-13 years. The prerequisite for such a study was the development of a method, which made it possible to study the nuclear DNA content in tumour cells obtained at the time of diagnosis, i.e. 6-13 years ago in the present material. A special cytochemical procedure with destaining of the original Giemsa stain, refixation and subsequent Feulgen staining of the smears of aspirates in the original cytological material was developed. The cytophotometric nuclear DNA analysis of tumour cells in smears of aspirate from mucoepidermoid carcinomas showed that higher ploidy tumours (near-triploid) had a worse prognosis when compared with near-diploid tumours. These data are supported by our previous findings that a shift from a near-diploid to a near-triploid DNA content of the tumour cell nuclei was associated with the prognostic important property of invasive growth. Thus, the cytophotometric nuclear DNA analysis of aspirated tumour cells seems to give valuable information about the malignancy degree of the individual tumour, which is not possible to obtain only from the cytomorphological features.