Clinical and Dermoscopic Characterization of Mixed-Type Basal Cell Carcinoma

Introduction: Basal cell carcinoma (BCC) is a malignant skin tumor that originates from epidermal basal cells or the outer root sheath of hair follicles. Identifying histopathological subtypes is crucial to guiding treatment and patient follow-up. While dermoscopic features associated with histopathological subtypes have been studied, the changes in dermoscopic findings in mixed-type BCC remain unclear. Objectives: This study aimed to analyze the demographic characteristics of patients diagnosed with single and mixed-type BCC and to investigate the correlation between clinical and dermoscopic findings and histopathological subtypes. Results: A total of 186 BCC lesions from 157 patients were analyzed. The mean patient age was 68.8±12.7 years (range: 30–94). The most common lesion location was the head and neck region (74.7%). The distribution of histopathological subtypes was as follows: nodular (42.5%), mixed-type (37.6%), superficial (12.4%), basosquamous (3.2%), infiltrative (2.7%), micronodular (1.1%), and fibroepithelial (0.5%). The most frequent mixed-type BCC combinations were nodular-infiltrative (32.9%), nodular-superficial (31.4%), and nodular-micronodular (12.9%). Short fine telangiectasia, yellow-white structureless areas, scales, and rosette structures were more frequent in mixed-type BCC. Corkscrew vessel patterns were more common in single-type lesions. The presence of a superficial component in mixed-type BCC was associated with wheel-like structures, while infiltrative components correlated with dotted and glomerular vessel patterns, and basosquamous components were linked to arborizing vessel patterns. Additionally, arborizing vessel patterns (P=0.019) and dotted vessel patterns (P=0.025) were associated with high-risk subtypes in mixed-type BCC. Conclusion: Our study suggests that dermoscopic findings may serve as a guide to recognizing mixed-type BCC lesions, distinguishing between subtype components, and assisting in treatment decision-making based on these observations.