Difficult to diagnose squamous cell carcinoma: a literature review and a case report

Squamous cell carcinoma (SCC) is the second most common type of skin cancer, right behind basal cell carcinoma (BCC), arising from the keratinocytes of the epidermis. It is typically associated with cumulative ultraviolet (UV) exposure, especially in childhood and youth. In recent years, immunosuppression, as therapeutic approach, has emerged as an increasingly important contributor to tumorigenesis, and the appearance of SCC in areas of chronic inflammation must also be kept in mind. While SCC is usually straightforward diagnosis due to its characteristic clinical presentation, some variants of SCC can be difficult to diagnose. These “difficult-to-diagnose” SCCs may present with atypical features, mimic other dermatological conditions, or arise in non-sun-exposed areas, leading to diagnostic challenges and delays in treatment. This paper discusses the clinical and histopathological features that complicate the diagnosis of SCC, with an emphasis on specific SCC subtypes and diagnostic techniques. We also present a case report of Bowen’s disease in a 78-year old patient.