LA DENSITOMETRIA NELLO STUDIO DELLA PARAPSORIASI IN CHIAZZE

Densitometry, a classical cytophotometric technique that quantitatively evaluates DNA content of cell nuclei, has been renewed through introduction of electronic technology; thus, we have chosen it to study larqe plaque parapsoriasis in prognostical terms. Six patients affected with a slowly progressing form of the disease were found to possess a normal diploid genome. In contrast, 2 surely positive neoplastic controls (1 aggressive form of mycosis fungoides; 1 lymphomatous erythroderma) showed tetraploidy and/or an increased S-phase cell fraction: this could mean active proliferation. This technique is simple, and does spare sample entireness (differently from laser flow cytometry). According to results given by other Authors, densitometry could be proposed as an interesting method to differentiate 'benign' parapsoriasis from insidious mycosis fungoides. Besides, sample preparation is easy (traditional Feulgen-Rossenbeck coloration, as modified by Pearse), within the reach of every equipe working together with an histopathology laboratory. Anyway, we must remark that it is necessary to evaluate critically densitometric results, and to integrate them within a wider context including clinical and other laboratory data. Only under these conditions, densitometry will be able to become an interesting method helping to define prognosis of puzzling lymphoproliferative diseases.