Balloon cell malignant melanoma.

A patient was seen with a pigmented plaque of malignant melanoma and multiple surrounding skin-colored dermal and subcutaneous nodules. Histologic examination showed that the pigmented lesion represented the balloon cell variant of malignant melanoma and that the adjacent nodules were local metastatic lesions. This case, along with a review of the literature, illustrates that many balloon cell melanomas show only mild cellular atypia and minimal mitotic figures, although the tumor has a malignant course, with local or distant metastasis. A careful examination of all the sections of the balloon cell tumor is important.