Aggressive basal cell carcinoma: dermatoscopy vascular features as clues to the diagnosis

BACKGROUND Basal cell carcinoma (BCC) can present with indolent or aggressive subtypes. These subtypes usually display vascular features, which are often readily identified using dermatoscopy. OBJECTIVE Dermatoscopy vascular features of aggressive BCC were compared to superficial, superficial and nodular, and nodular BCC for diagnostic discrimination. METHOD Dermatoscopy vascular features were recorded live direct from the patient for 1,098 consecutive BCC. Cases with potential confounding influences were excluded. These tumor vascular features included branching (arborizing), serpentine, dot, coil (glomerular), loop (hairpin) and linear vessels. The proportion of pink within the tumor, central versus peripheral tumor vessel distribution and the presence of large vessels within the tumor boundary were also recorded. RESULTS Different subtypes of BCC have distinctive vascular features. Aggressive BCC (n=213) displays a tumor area with no pink (12.2%) or less than half the area pink (27.2%) and absent vessels in the central tumor area (22.1%, CI 17.0%-28.1%, P<0.001) compared to other subtypes. Superficial BCC (n=284) have more than half the tumor area pink (84.9%) and absent large vessels (92.6%), CI 89.0%-95.1%. Nodular BCC (n=230) is characterized by larger vessels (45.7%, CI 39.3%-52.1%, P<0.001) as compared to other subtypes, as well as less dot, coil and loop vessels. Kappa values for all recorded features ranged from 0.48 to 1.0. LIMITATIONS Aggressive BCCs within the combined aggressive group were not assessed separately. CONCLUSIONS Diagnostic discrimination between different subtypes of BCC is facilitated by vascular feature assessment. Compared to other subtypes, aggressive BCC displays less or no pink and less or absent central tumor vessels.