What are the key clinical features that differentiate cutaneous squamous cell carcinoma from other skin lesions?

Key clinical features that differentiate cutaneous squamous cell carcinoma (cSCC) from other skin lesions include:

• A persistent, non-healing, scaly or crusted lesion often with an irregular surface, which may ulcerate or bleed spontaneously, distinguishing it from benign lesions like actinic keratosis or seborrhoeic keratosis NICE NG12.
• Lesions typically present as firm, erythematous papules, plaques, or nodules that may be tender or painful, unlike basal cell carcinoma which often appears pearly and translucent NICE NG12.
• Rapid growth over weeks to months is more characteristic of cSCC compared to slower-growing benign lesions or other skin cancers NICE NG12.
• Commonly arises on sun-exposed areas such as the face, ears, neck, and hands, which helps differentiate it from other lesions with different distribution patterns NICE NG12.
• Dermoscopy may reveal specific features such as glomerular or dotted vessels and scaling, which are more suggestive of cSCC compared to other lesions Zhu et al. 2024.
• Histologically, cSCC shows invasive atypical keratinocytes with keratin pearl formation, which is distinct from other skin cancers and benign lesions Dessinioti et al. 2024.
• In situ variants like Bowen disease present as well-demarcated, erythematous, scaly plaques, which can be differentiated clinically and histologically from invasive cSCC and other dermatoses Scurtu et al. 2024.

In summary, the combination of a persistent, scaly, sometimes ulcerated lesion on sun-exposed skin, rapid growth, characteristic dermoscopic vascular patterns, and histological confirmation are key to differentiating cSCC from other skin lesions NICE NG12 Dessinioti et al. 2024Zhu et al. 2024Scurtu et al. 2024.