Environmental modification of the shape of pigment-producing cells.

With fluorescence-histochemical methods (FIF method) pigment-producing cells were investigated in benign and malignant skin lesions. Here, pigment cells appear predominantly dendritic, whilst they are separated from each other by keratinocytes, cells of hair follicles, or cells of sebaceous glands. In lentigo maligna melanoma, superficial spreading melanoma as well as in nodular melanoma and some metastases of these melanomas, the tumour cells can show a dendritic pattern under special environmental situations. It is, therefore, assumed that the shape of tumour cells in melanomas is more closely dependent on their particular environment and other modifying factors than on a different histogenesis.