We report a case of major regression of multiple atypical
melanocytic nevi with a vitiligoid reaction in a patient with metastatic
melanoma who achieved long-lasting complete remission after
ipilimumab therapy. In 2008, a 54-year-old man presented with a
dysplastic nevus syndrome. The patient was diagnosed with a scalp ulcerated
melanoma (Breslow index 5.1 mm and Clark level IV), which was removed surgically. Four years later in April 2012, the patient was diagnosed with a right parietal skin
metastasis, brain, lymph nodes, and bilateral lung
metastases. The patient was first treated with
vemurafenib, which had to be stopped because of renal toxicity. Disease stabilization was achieved after the second line of treatment with
immunotherapy (
ipilimumab, four infusions). However, 6 months later, the lung
metastases had progressed. The patient was treated with pulmonary stereotactic
radiotherapy associated with a second cycle of
ipilimumab. After 6 months, he achieved complete remission. Simultaneously, the patient presented a generalized regression of his
nevi with a vitiligoid reaction, or
halo nevus, associated with a
vitiligo located on the hands and inguinal areas.
Vitiligo is a frequent immune-related adverse event of
immunotherapy.
Immunotherapy-induced
halo nevus reaction is much less frequent than
vitiligo. It was associated in the two case reports from the literature and in our patient with a quick and long-lasting complete remission of nodes and visceral
metastases. Therefore, it might correspond to a stronger antimelanocyte immune reaction, associated with a favorable prognosis. The generalized
halo nevi reaction in our patient could be more important because of the two cycles of
ipilimumab compared with a single one. In conclusion, this case report suggests that a major regression of multiple
nevi on
ipilimumab might be associated with
immunotherapy response.