Eruptive pigmentation around naevi and seborrhoeic keratoses in a patient with stage III melanoma: hyperpigmented halo or ‘Nottus’ phenomenon

Abstract

Funding sources: none. Conflicts of interest: none declared. Madam, The appearance of white, vitiligo‐like macules around pigmented moles (Sutton halo naevus or Sutton phenomenon) is a well‐known phenomenon, and has been described in the context of melanoma. We report the case of a man with stage III melanoma who developed a sudden and synchronous, eruptive pigmentation around most of his naevi and seborrhoeic keratoses. A 65‐year‐old man with a medical history of tobacco smoking and dyslipidaemia presented in March 2006 with an extensive subcutaneous mass of the right scapular region, which was resected. Histological examination demonstrated dermal metastasis of melanoma. Thorough skin examination revealed many melanocytic naevi without atypical features and a few seborrhoeic keratoses, but no lesion consistent with primitive cutaneous melanoma. A highly suspect, enlarged, right axillary lymph node was detected and lymph node dissection was performed in December 2006, showing melanoma metastases with extracapsular extension in two of 12 resected lymph nodes. Staging investigations, including a positron‐emission tomography scan and a full body computed tomography (CT) scan, did not detect any visceral metastasis. Adjuvant immunotherapy with interferon alfa‐2a (3 × 3 million IU weekly) was administered, but had to be discontinued 5 months later because of liver enzyme elevation. At a follow‐up visit 6 months after discontinuation of the treatment, a striking modification of his skin lesions was noted. Most of his naevi were surrounded by a light‐brown, ill‐defined, round or oval macular halo (Fig. 1), associated with brownish macules without a central lesion. He had experienced neither pruritus nor perilesional erythema, and his general condition was good. Histological examination of five lesions surrounded by brown macules demonstrated hypermelanosis of the epidermal basal layer without significant melanocytic hyperplasia in the periphery (corresponding to the pigmented halo) (Fig. 2), and a typical compound dermal naevus in the centre. In one sample, the central brown papule corresponded to a seborrhoeic keratosis (not shown). There was no pigmentary incontinence, melanophages, inflammatory cells or fibrosis in the underlying dermis. A full body CT scan at this time did not reveal any visceral metastasis, while urine analysis ruled out melanuria. Regular clinical and paraclinical follow‐up was pursued, allowing the detection in 2010 of a right axillar metastatic lymph node recurrence, treated with lymph node dissection. Since this date, he has remained recurrence free.