Eruptive Nevi Mimicking Wart-Like Lesions under Selective BRAF Inhibition in a 37-Year-Old Female Melanoma Patient

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.

Drug-induced eruptive melanocytic nevi

INTRODUCTION

The sudden eruption of melanocytic nevi has been associated with a number of conditions, such as bullous skin diseases, immunodeficiency and immunosuppression. The exact mechanisms leading to the development of eruptive melanocytic nevi are unknown. Areas covered: The aim of this article is to review the literature concerning eruptive melanocytic nevi following the administration of immunosuppressive drugs and other medications. Expert opinion: The literature regarding the development of eruptive nevi in association with pharmacological therapies includes a relatively low number of reports. Prevalence of this phenomenon is likely to be underestimated, thus reporting should be encouraged in order to better define the actual significance and related clinical implications. The development of multiple melanocytic nevi during immunosuppressive treatments highlights the importance of immune system integrity in the regulation of nevi growth. The observation of eruptive nevi as an unexpected effect of targeted therapies for specific types of cancer, including melanoma, provided intriguing hints to understand the mechanisms underlying this paradoxical event. The synergistic role of additional triggers in the occurrence of drug-induced eruptive nevi has not been explored and may be an interesting area of research.

Cutaneous adverse events in patients treated with BRAF inhibitor-based therapies for metastatic melanoma for longer than 52 weeks

BACKGROUND

BRAF inhibitor-based therapies have been shown to induce cutaneous toxicities, with onset generally in the first 8-26 weeks of therapy.

OBJECTIVES

To determine whether cutaneous toxicities persist in patients who have remained on BRAF inhibitor-based therapies for longer than 52 weeks, and therefore whether ongoing dermatology assessment is required.

METHODS

All patients treated with the BRAF inhibitors vemurafenib or dabrafenib or combination BRAF inhibitor and mitogen-activated protein kinase kinase (MEK) inhibitor therapy at Westmead Hospital, Sydney, Australia underwent regular dermatological assessments for the duration of therapy. All patients enrolled in a clinical trial, and 18% of patients in the compassionate access scheme underwent a baseline assessment prior to commencement of therapy and every 4-8 weeks thereafter. Patients' adverse events were recorded in a specific database.

RESULTS

Patients continued to develop cutaneous adverse events after 52 weeks of continuous therapy. Patients on single-agent BRAF inhibitor therapy suffered from Grover disease (45%), plantar hyperkeratosis (45%), verrucal keratosis (18%) and even cutaneous squamous cell carcinoma (16%). The most frequent adverse event seen in patients in the combination BRAF and MEK inhibitor group was an acneiform eruption (40%).

CONCLUSIONS

Patients on BRAF inhibitor-based therapies need to continue to have regular dermatological follow-up independent of the duration of their therapy.

Melanoma patients under vemurafenib: prospective follow-up of melanocytic lesions by digital dermoscopy

Second primary melanomas (SPMs) induced by vemurafenib have been recently described. The aim of this study was to define the dermoscopical signs of melanoma in this context. Patients underwent a total body examination before receiving vemurafenib. Each single melanocytic lesion was registered before therapy by digital dermoscopy (DD), and then repeated monthly until therapy disruption. Forty-two patients were included, the mean duration of follow-up was 6.7 months, and a mean number of 51 lesions per patients were captured and followed. A total number of 2,155 lesions were recorded, of which 56.1% presented at least one change during the study. More common changes concerned the color of the lesions (up to 15%) and appearance or disappearance of globules (14.6%). Thirty-six of the melanocytic lesions were surgically excised, 21 were classified as a nevus, 1 was a lentigo, and 14 as a second new primary melanoma (occurring in 21% of our patients). DD allowed us to excise only 36/2,155 (1.6%) of the lesions and permitted us to detect 14 SPM in the 42 patients with a highly efficient malignant/benign ratio of 63.6%. Although vemurafenib is now tested in an adjuvant setting DD should be systematically used in order to accurately detect SPM and reduce the number of unnecessary excisions.