Process Discerns Sun-Exposed Skin from Melanoma
Many normal sun-exposed skin samples show increased melanocyte confluence and density
TUESDAY, July 18 (HealthDay News) -- Researchers have determined the number of melanocytes in normal Caucasian sun-aged skin that can be used to distinguish it from early in situ melanoma, according to a report in the July issue of the Archives of Dermatology.
Ali Hendi, M.D., from the Mayo Clinic in Jacksonville, Fla., and colleagues randomly selected skin samples from 149 patients undergoing treatment for basal and squamous cell carcinoma of the face and neck. They used the samples to determine the level of melanoma antigen recognized by T cells 1 (MART-1) immunostaining in normal long-standing sun-exposed skin.
The investigators found a mean of 15.6 melanocytes per x400 magnification field with 89 percent of samples showing some degree of confluence and 24.2 percent showing increased density. They did not see pagetoid spread or nesting of melanocytes. About half their samples showed non-specific scattered MART-1 stained cells.
"Melanocytes in long-standing sun-exposed skin have an increased density and a confluence that is often moderate (three to six adjacent melanocytes), but they do not exhibit pagetoid spread or nesting," the authors conclude. "Non-specific MART-1-staining dermal cells should not be interpreted as invasive melanoma."