From the Guidelines
Squamous cell carcinoma in situ of the nail unit can present with various symptoms, including hyperkeratotic, papillomatous or warty proliferations, erosions or scaling of the nail fold, and should be treated as if there is a concurrent invasive component due to the difficulty in diagnosing SCC vs. SCC in situ with periungual lesions. When considering lines on nails, it is essential to differentiate between benign and potentially malignant conditions. According to the British Association of Dermatologists' guidelines for the management of squamous cell carcinoma in situ (Bowen's disease) 2014 1, squamous cell carcinoma in situ can present in any part of the nail unit or periungual tissue. Key symptoms to look out for include:
- Hyperkeratotic, papillomatous or warty proliferations
- Erosions or scaling of the nail fold
- Whitish cuticle
- Periungual swelling, paronychia and fissure or ulceration of the lateral nail groove
- Subungual involvement, which is the most common presentation, and may also present with onycholysis and extensive hyperkeratosis of the nail bed
- Longitudinal melanonychia as a presenting feature of SCC in situ of the nail. The presence of ulceration, bleeding or a nodule is indicative of the transformation to invasive carcinoma, which has a low rate of metastases, approximately 2% 1. Given the potential for malignancy and the difficulty in diagnosing SCC vs. SCC in situ with periungual lesions, it is crucial to treat biopsy specimens indicating SCC in situ as if there is a concurrent invasive component. If the condition persists, the threshold for a repeat biopsy should be low to ensure timely diagnosis and treatment.
From the Research
Nail Lines
- Nail lines are a common presenting finding and can be a clue to underlying systemic diseases or infections 2
- There are different types of nail lines, including:
- Leukonychia striata (white lines)
- Longitudinal melanonychia (brown-black lines)
- Longitudinal erythronychia (red lines)
- Nail-plate grooves (Beau lines) 2
- Each type of nail line has a particular differential diagnosis and can be used to diagnose and treat nail disorders 2
Diagnosis and Treatment
- A thorough inspection of the fingernails and toenails is an integral part of the complete physical examination 2, 3
- Diagnosis of nail diseases should include a detailed history and clinical examination of all 20 nail units 4
- Treatments for nail diseases include topical and/or systemic medications, discontinuation of offending drugs or surgical intervention, depending on the condition 4
- Patient education on proper nail care and techniques to minimize further damage to the affected nails is also important 4