Subungual melanoma: a deceptive disorder

Area of Science:

• Dermatology
• Oncology

Background:

• Subungual melanoma is an uncommon acral melanoma variant originating in the nail bed.
• Its incidence varies globally, with a higher proportion observed in individuals with darker skin tones.
• It accounts for approximately 2% of non-sun-induced cutaneous melanomas in Western populations, but significantly higher percentages in other ethnicities.

Purpose of the Study:

• To highlight the epidemiological variations of subungual melanoma across different populations.
• To emphasize the diagnostic challenges, including amelanosis and non-specific symptoms.
• To underscore the impact of delayed diagnosis on prognosis and treatment.

Main Methods:

• Literature review and epidemiological data analysis.
• Clinical presentation and diagnostic clue identification.
• Prognostic factor assessment.

Main Results:

• Subungual melanoma prevalence is higher in Africans (up to 75%), Japanese (10%), and Hong Kong Chinese (25%) compared to Western populations (2%).
• Up to 33% of cases are amelanotic, presenting without typical pigmentation.
• Hutchinson's sign (melanonychia of the adjacent nail fold) can be a diagnostic indicator.

Conclusions:

• Subungual melanoma exhibits significant ethnic variations in incidence.
• Amelanosis and non-specific symptoms contribute to delayed diagnosis, worsening patient outcomes.
• Early recognition and prompt treatment are crucial for improving the prognosis of this challenging cancer.