['Overexpression of the c-myc oncoprotein has been observed to be of prognostic significance in several human cancers. This study was undertaken to establish whether c-myc has any prognostic significance in melanoma.', 'Expression of c-myc oncoprotein was studied in a prospective series of primary and secondary malignant melanomas. Ethanol-fixed tissue was digested into nuclei and stained for flow cytometric analysis using a pan-myc antibody.', 'Overexpression of the c-myc oncoprotein was prevalent in both disease stages. In primary disease, overexpression was associated with tumour thickness and with the presence of ulceration, age and reduced disease-free interval. Of most importance, high expression of c-myc predicted poor outcome in both primary and metastatic disease. In addition, c-myc was able to discriminate prognosis in melanomas uniformly stratified as thick (greater than 3 mm) lesions.'] Does expression of c-myc oncoprotein represent a new prognostic marker in cutaneous melanoma?