Poliosis, a localized patch of white hair, may rarely signal underlying melanoma, particularly when appearing over a melanocytic lesion.1 We report a case of poliosis over the scalp associated with melanoma arising on a congenital nevus and provide a brief literature review.

A 30-year-old man with no relevant medical history presented with a painful, palpable nodule on the right parotid region, evolving over five months. Histological evaluation of the lesion confirmed intraparotid lymph node metastasis of melanoma. Clinical examination revealed a congenital melanocytic nevus measuring 8 × 6 cm in the right temporal scalp, with recent enlargement and a central area of white hair (Fig. 1). Partial biopsy confirmed melanoma arising in a congenital nevus.

Fig. 1.

(A) Initial presentation showing localized white hair (poliosis) within a congenital nevus on the right temporal scalp. (B) Same lesion after partial shaving reveals central ulceration and color heterogeneity; histopathology confirmed invasive melanoma arising within the nevus.

The patient underwent complete excision of the lesion, total parotidectomy with facial nerve preservation, and right posterior cervical lymphadenectomy. A staging body CT scan excluded distant metastasis (M0). Histopathology showed invasive melanoma on a congenital nevus (Breslow 1.8 mm, Clark level III, ulceration, regression, 2 mitoses/mm2, BRAF V600E positive) (Fig. 2), with 4 of 37 lymph nodes involved, one with extracapsular extension, corresponding to stage IIIC (AJCC 8). Adjuvant immunotherapy with pembrolizumab was administered for one year, and after 15-months of follow-up, the patient remains free of metastasis.

Fig. 2.

(A) Hematoxylin & eosin stain, original magnification ×10. Continuous lentiginous growth of atypical melanocytes with formation of large nests. Melanocytic infiltration of the deep dermis and adnexal structures is also observed, a characteristic feature of congenital nevi. (B) Hematoxylin & eosin stain, original magnification ×40. Large, atypical melanocytes showing pagetoid spread and infiltration of the hair follicle.

Poliosis has been associated with a broad spectrum of conditions, including autoimmune diseases (e.g., vitiligo, Vogt-Koyanagi-Harada, alopecia areata), inflammatory dermatoses, drug reactions (e.g., prostaglandin analogues, checkpoint inhibitors), and both benign and malignant tumors.2,3 In melanoma, poliosis may reflect the destruction of follicular melanocytes through immune-mediated mechanisms. Molecular mimicry or shared antigens between melanoma cells and follicular melanocytes may explain this phenomenon.

We identified 8 previously reported cases in the literature directly linking circumscribed poliosis to melanoma (Table 1, Supplementary Table S1 and Fig. S1). Among these cases, most occurred in men and involved the scalp. Two cases described poliosis of the eyelashes associated with ocular melanomas ‒ one conjunctival and one orbital ‒ highlighting the relevance of poliosis in this site as a potential clue to intraocular disease. Additionally, in two cases, poliosis appeared at locations distant from the primary tumor, including the scalp and eyelashes, while the melanoma was located on the lower limb. This suggests that poliosis may occasionally act as a clinical marker of metastatic spread from a distant primary melanoma.

Histological features frequently included areas of regression and fibrosis in association with poliosis. Though regression in melanoma remains a debated prognostic factor, recent meta-analyses suggest it may be associated with improved survival.4 Nevertheless, in this small series, 5 of 9 patients showed nodal or systemic involvement, underscoring the importance of prompt recognition and staging. With these findings, poliosis may represent a late-stage sign, potentially associated with a poorer prognosis in melanoma.

Scalp melanomas comprise 3%–5% of cutaneous melanomas but are associated with delayed diagnosis and worse outcomes. Their frequent amelanotic presentation contributes to diagnostic difficulty.5 In this context, the emergence of localized poliosis over a nevus, particularly in adults, should prompt immediate dermoscopic evaluation and consideration of biopsy.

In conclusion, we present a rare case of melanoma arising in a congenital scalp nevus associated with circumscribed poliosis. Clinicians should consider recent onset of poliosis over melanocytic lesions as a potential clinical sign of melanoma requiring early investigation. Special attention should be paid to poliosis of the eyelashes, which may reflect not only ocular melanoma but also metastatic disease from a distant primary tumor.