Eruptive melanocytic nevi heralding the diagnosis of metastatic malignant melanoma: A case report

Eruptive melanocytic nevi in a patient with amelanotic melanoma: a paraneoplastic phenomenon?

Eruptive melanocytic nevi (EMN) describes the sudden onset of cutaneous nevi over weeks or months. Such a clinical event is generally seen in young adult patients and may be related to several possible causes. We report here a case of EMN in an old male patient followed up for a thick amelanotic cutaneous melanoma. A few months after the eruption, multiple hepatic masses, diagnosed as melanoma metastasis, were detected. The presented case may suggest that EMN may be a paraneoplastic phenomenon of alert in patients being followed for melanoma or other malignancies.

Imatinib-induced eruptive nevi

Imatinib mesylate is a tyrosine kinase inhibitor used in the treatment of a variety of oncological conditions. It has been associated with a spectrum of pigmentary cutaneous side effects. Despite the well-known association of eruptive melanocytic nevi with the use of other tyrosine kinase inhibitors, this phenomenon has not been linked to the administration of imatinib. We present the first case of imatinib-induced eruptive nevi in an 18-year-old patient with acute lymphocytic leukaemia in remission.

Eruptive Melanocytic Nevi: A Review

Eruptive melanocytic nevi (EMN) is a phenomenon characterized by the sudden onset of nevi. Our objective was to compile all published reports of EMN to identify possible precipitating factors and to evaluate the clinical appearance and course. We conducted a systematic bibliographic search and selected 93 articles, representing 179 patients with EMN. The suspected causes were skin and other diseases (50%); immunosuppressive agents, chemotherapy or melanotan (41%); and miscellaneous, including idiopathic (9%). The clinical manifestations could largely be divided into two categories: EMN associated with skin diseases were frequently few in number (fewer than ten nevi), large, and localized to the site of previous skin disease, whereas those due to other causes presented most often with multiple small widespread nevi. In general, EMN seem to persist unchanged after their appearance, but development over several years or fading has also been reported. Overall, 16% of the cases had at least one histologically confirmed dysplastic nevus. Five cases of associated melanoma were reported. We conclude that the clinical appearance of EMN may differ according to the suggested triggering factor. Based on the clinical distinction, we propose a new subclassification of EMN: (1) widespread eruptive nevi (WEN), with numerous small nevi, triggered by, for example, drugs and internal diseases, and (2) Köbner-like eruptive nevi, often with big and few nevi, associated with skin diseases and most often localized at the site of previous skin disease/trauma. The nature of the data precluded assessment of risk of malignant transformation.