Balloon cell melanoma: a report of two cases.

Two cases of balloon cell malignant melanoma of the skin are reported. The first lesion was pigmented, the second was amelanotic. Histologically, the tumor mass was dermal and intraepidermal and almost exclusively composed of balloon cells. Many of the clear cells demonstrated postivity with the S-100 protein immunostaining. The problems of clear-cell tumor differential diagnosis are discussed.