Vitiligo- and melanoma-associated hypopigmentation: a similar appearance but a different mechanism.

The significance of the association between the appearance of hypopigmentation in patients with melanoma and the prognosis is still not clear. It was postulated that, in melanoma, an immune response is responsible for the destruction of the malignant as well as the normal pigmented cells, and that the eventual development of vitiligo-like patches in melanoma patients improves their prognosis. We studied the level of anti-melanoma antibodies in the sera of patients with melanoma with hypopigmentation and compared it to the titer in patients with melanoma only, to the titer of patients with vitiligo, and to that of healthy subjects. Only IgG-type antibodies were found in the sera of patients with vitiligo, with melanoma, or with melanoma with hypopigmentation. No significant differences in the titer of anti-melanoma antibodies could be found between the patients with melanoma when subgrouped according to the initial stage and the status of the disease at the time when the test was carried out. Statistically significantly (P < 0.001) higher titers of antibodies were detected in the sera of patients with vitiligo in comparison to the lower titers in the other groups. Our results point to a similar immunobiological status, which probably does not give any advantage to patients with melanoma with hypopigmentation compared to patients without it. The appearance of hypopigmentary plaques in melanoma patients should be regarded, in our opinion, as a concomitant immunological phenomenon of the disease.