Nevus. A, Clinical features; B, nail plate dermoscopy; C, intraoperative dermoscopy. ABCDEF rule information: A (age, 35 years), C (change in band at 2 years; it became enlarged or darker), D (digit, third finger, right hand), and F (no family or personal history of melanoma)
Only 46-55% made the correct diagnosis of nail matrix melanoma in situ in this study. The level of expertise did not statistically influence the correct diagnosis.
- A (age as peak incidence of nail melanoma is between 50 and 70 years. A also reminds us of most commonly affected races: African Americans, Asians, and Native Americans).
- B (band: black to brown, breadth > than 3 mm, blurred borders)
- C (change: enlarging or darkening)
- D (digit: most fingernail melanomas affect the dominant hand)
- E (extension of the pigmentation to the surrounding tissues)
- F (family or personal history of melanoma)
Amelanotic NAM represents 20% to 30% of ungual melanoma cases compared with less than 7% of the other cutaneous melanomas.It usually presents as a chronic paronychia, a torpid granulomatous ulceration, a wartlike keratotic tumor, or a pyogenic granuloma.It is usually located in the periungual folds or in the nail bed.Clinical misdiagnosis, which is particularly frequent in amelanotic melanoma, is responsible for a delay in diagnosis as well as a poor prognosis.
Dermatologists' Accuracy in Early Diagnosis of Melanoma of the Nail Matrix; Nilton Di Chiacchio; Sergio Henrique Hirata; Mauro Yoshiaki Enokihara; Nilceo S. Michalany; Gabriella Fabbrocini; Antonella Tosti; Arch Dermatol. 2010;146(4):382-387.
In Situ Amelanotic Melanoma of the Nail Unit Mimicking Lichen Planus: Report of 3 Cases; Josette André; Isabelle Moulonguet; Sophie Goettmann-Bonvallot; Arch Dermatol. 2010;146(4):418-421.