Autocrine growth stimulation as a potential source of asymmetry in melanocytic skin tumors

The presence of asymmetry is a major diagnostic criterion for the differentiation of melanoma from benign melanocytic proliferations. It is helpful in both clinical and histological evaluation. The underlying biological features that determine asymmetry have not yet been evaluated. Using computer simulation of the growth of neoplasms, we demonstrate that a functionally homogeneous cell population can give rise to asymmetric lesions when the cells respond to autocrine growth signals. In contrast, neoplastic cells that depend on paracrine stimuli tend to form symmetric lesions. Since the progression of melanocytic neoplasms has been demonstrated to be accompanied by increasing independence of paracrine growth signals and the development of autocrine loops, autocrine growth stimulation has to be considered as a potential source of asymmetry in melanoma.