Arborizing Vessels on Dermoscopy in Various Skin Diseases Other Than Basal Cell Carcinoma

BACKGROUND: Arborizing vessels (AVs) are dermoscopically defined as telangiectasias with distinct treelike branching, and are a characteristic feature of basal cell carcinoma (BCC). However, AVs are observed in various conditions other than BCC. OBJECTIVE: The aim of this study was to investigate skin diseases showing AV and investigates dermoscopic differences between BCC and non-BCC. METHODS: Dermoscopic images showing AV were prospectively collected and classified into BCC/non-BCC. Non-BCC was further classified into tumors (benign cystic, benign non-cystic, premalignant, and malignant) and non-tumors. We compared AV focusing, widest diameter of stem vessels, widest diameter ratio of stem vessel to first branch, and number of ramifications between groups. RESULTS: Among 124 images, 54.0% were BCC and 46.0% were non-BCC. Non-BCC included epidermal cysts, hypertrophic scars/keloids, intradermal nevi, actinic keratoses, etc. The proportion of focused AV in BCC was significantly higher and the proportion of unfocused AV in BCC was lower than that of premalignant and malignant non-BCC. The widest diameter ratio of stem vessel to first branch was higher in non-BCC. Number of ramifications was significantly less in benign cystic non-BCC than BCC. CONCLUSION: Various skin diseases showed AV, so that diagnoses other than BCC should be considered. The findings in this study could help discriminate BCC from non-BCC.