Nail Unit Melanoma: Uncommon Presentations to Keep in Mind.

Area of Science:

• Dermatology
• Oncology
• Pathology

Background:

• Nail unit melanoma (NUM) is a significant variant of malignant melanoma, particularly in certain ethnic groups.
• Unlike other melanomas, NUM is often linked to factors like trauma and chronic inflammation, not sun exposure.
• While common on toes and thumbs, NUM originating from the hyponychium is exceptionally rare.

Purpose of the Study:

• To present a case of hyponychial nail unit melanoma (NUM).
• To emphasize the diagnostic utility of dermoscopy for pigmented lesions of the nail unit.
• To highlight the need for personalized treatment strategies due to the lack of standardized NUM guidelines.

Main Methods:

• A clinical case presentation of a 72-year-old woman with a pigmented lesion on her right second finger.
• Dermoscopic examination of the lesion.
• Histopathological confirmation of acral lentiginous melanoma.
• Surgical excision of the nail unit with a 5-mm margin toward the hyponychium.

Main Results:

• The patient presented with a hyperpigmented macule exhibiting irregular borders and heterogeneous pigment distribution.
• Biopsy confirmed acral lentiginous melanoma.
• Surgical intervention was performed with a 5-mm margin.

Conclusions:

• NUM, especially from the hyponychium, presents unique diagnostic challenges.
• Dermoscopy is an indispensable tool for evaluating pigmented nail unit lesions.
• Individualized surgical approaches, including conservative options, are vital for managing NUM while preserving function and survival.