We report a composite nodular ganglioneuroblastoma, distinctive for th
e presence of coarsely granular black intracellular pigment, which was
histochemically indistinguishable from melanin. Ultrastructurally, th
e pigment was resolved as numerous heterogeneous lysosomes, containing
material compatible with oxidized lipid residues, the accumulation of
which may reflect acquired lysosomal dysfunction in individual tumour
cells-a tumour cell 'storage disease'.