Abstract
Accurate clinical diagnosis of skin cancer allows for timely treatment, however, distinguishing between keratinocyte carcinoma (KC) subtypes based solely on clinical examination is challenging due to overlapping features. This study aims to evaluate the congruence between clinically diagnosed basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) and their corresponding histopathological diagnoses. Data collected retrospectively from 11,145 KCs diagnosed between January 2017 and December 2021 provided information on the subtype of BCC or SCC a lesion was initially diagnosed with and its corresponding histologic diagnosis. There was an overall clinical mismatch rate of 10.63% among all KCs, with SCC subtypes having a notably higher clinical mismatch rate (15.83%) compared to BCC subtypes (7.03%). The most clinically misdiagnosed lesion was poorly differentiated SCC with a mismatch rate of 38.46%. Alternatively, sclerosing BCC was the least misdiagnosed with a mismatch rate of 1.33%. The high mismatch rate in poorly differentiated SCC may be attributed to its atypical presentation, diverging from typical SCC characteristics as a flat lesion with the absence of scaling, keratin, or bleeding, leading to the misdiagnosis of BCC. Dermoscopy is recognized as a valuable tool as it provides improved diagnostic abilities compared to a naked-eye examination, but its limitations with the ambiguous characteristics of some lesions may still lead to misdiagnosis. Though our data presents an overall high rate of diagnostic accuracy upon suspicion of malignancy, the different variables affecting clinical presentation highlight the unmatched diagnostic capabilities of histological examination in skin cancer diagnoses.