Mortality from melanoma, the deadliest of skin cancers, continues to increase in all age
groups. A small number of melanomas spontaneously regress. In vitro studies suggest a role
for the natural killer cell in effecting regression. In this study, the goal was to determine if
natural killer cells are preferentially involved in the cytotoxic response in regressing lesions.
Forty-two cases were selected: nevi with regression, nonregressing melanoma with brisk
inflammation, and regressing melanoma. Sections were stained with hematoxylin and eosin …