Serpentine supravenous hyperpigmentation induced by the nitrosourea fotemustine.

Two cases of serpentine supravenous hyperpigmentation developing in the area of fotemustine infusions are reported. Histological features showed an increased melanin synthesis and the presence of melanophages without focal degeneration of basal cells or dermal inflammatory infiltrate. Perls' strain was negative. Hypotheses concerning the mechanisms of increased melanin synthesis over the veins are discussed.