[Familial multiple naevogene melanomas. Electronmicroscopical findings in pigmented moles of the B-K-mole syndrome (author's transl)].

Report of a patient with familial melanocytic moles and melanomas as designated by Clark et al. as B-K-mole-syndrome. Beside the typical clinical and histological features, the ultrastructural changes of B-K-moles are described. Nevus cells in these moles showed lobed nuclei, active Golgi complexes and swollen mitochondriae. Membrane rich melanosomes and melanosome complexes were found. The B-K-moles had no distinctive ultrastructure. An ultrastructural differentiation between tumor cells of the B-K-moles and melanoma cells was not possible.