Introduction: Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer, accounting for 20% of malignant skin tumors. Dermoscopy is a very useful tool for diagnosing cSCC, and its findings are confirmed through histopathological studies.
Objectives: to describe the different dermoscopic structures of invasive cSCC and investigate their association with the clinical form and histopathological grade of differentiation.
Methods: We conducted a cross-sectional study, collecting all patients diagnosed with squamous cell carcinoma over a period of 5 years. The study population was divided into two groups based on histological differentiation (well-differentiated and non-well-differentiated) and clinical form ( nodulo-ulcerative and nodular). Various dermoscopic parameters were compared between these groups.
Results: Out of 72 invasive cSCC, 81.9% were well-differentiated, while 18.1% were non-well-differentiated. The clinical form of cSCC was nodulo-ulcerative in 83.3% of cases and nodular in 16.7%. Well-differentiated tumors showed dotted, glomerular and hairpin vessels, along with a predominant white pattern characterized by centrally distributed keratin as well as white circles, and whitish perivascular halo (P < 0.05). The distribution of these white structures was radial in nodulo-ulcerarive lesions, whereas in nodular lesions, their distribution, as well as that of keratin, was more diffuse (P < 0.05). Non-well-differentiated tumors showed a combined white-red pattern with the predominance of arborizing vessels (P < 0.05).
Conclusions: Our results show the reliability of dermoscopy as a tool for distinguishing between well- and poorly differentiated cSCC. This distinction is characterized by an increase in predominantly arborizing vessels and a corresponding decrease in white structures as the tumor progresses from a well-differentiated to a poorly differentiated state. Additionally, the nodulo-ulcerative form exhibits a central distribution of keratin, while the nodular form displays a diffuse distribution.