Squamous cell carcinoma of the nail unit (nSCC) is a rare malignant tumor of the hand and nail. Although skin cancer rarely affects individuals with phototypes IV-VI, its occurrence in these groups is often associated with greater morbidity and mortality. This study aims to characterize the clinical symptoms, presentations, and treatments of nSCC in patients with darker skin types. A systematic review of PubMed and Embase was performed in May 2023 for all peer-reviewed, English-language nSCC studies involving individuals with Fitzpatrick types IV-VI. Most tumors were located on the fingernails (84%), with the right third finger being the most frequently affected (31%). The nail bed (67%) exhibited a higher prevalence than the lateral/proximal nail folds (33%). The duration of symptoms before diagnosis ranged from 1 month to 7 years. nSCC was most commonly treated with Mohs surgery (38%), followed by amputation (35%). Our study was limited to case reports because of a lack of large nSCC studies that provide information on race or images of each patient. These tumors are generally slow-growing yet often misdiagnosed, leading to delays in presentation and diagnosis. Increased awareness about nSCC in phototype IV-VI individuals will reduce misdiagnoses, unnecessary treatment, and recurrences.
Keywords: Fitzpatrick; cancer; nail; nail unit; skin of color (SOC); squamous cell carcinoma; subungual.
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