Extensive Dermoscopic Ulceration and Brown Globules Predict Aggressive Subtypes of Basal Cell Carcinoma

Background Basal cell carcinoma (BCC) subtypes differ in biological behaviour, with aggressive variants demonstrating increased invasiveness and recurrence risk. Reliable dermoscopic indicators require further investigation. Objectives To evaluate whether semi‐quantitative assessment of dermoscopic ulceration and selected features improves recognition of aggressive BCC. Methods This retrospective study included histopathologically confirmed BCCs (April 2020–April 2024). Inclusion required definitive subtype classification and a pre‐treatment dermoscopic image. Tumours were categorised as superficial, non‐superficial low‐risk, or aggressive. Ulceration (0%, < 50%, > 50%, 100%) and dermoscopic features were assessed by three blinded investigators. Subgroup analyses investigated ulceration extent in infiltrative BCC, and brown globules in micronodular BCC. Results Of 1040 lesions, 842 BCCs from 759 patients were included (22.6% superficial, 64.1% low‐risk, 13.3% aggressive). Increasing ulceration extent demonstrated a dose–response relationship with aggressiveness (univariate OR: 1.80, 95% CI: 1.01–3.20 for 50%–99% ulceration; OR: 2.94, 95% CI: 1.60–5.40 for 100% ulceration). Ulceration ≥ 50% was associated with a twofold increased risk of aggressive BCC (adjusted OR [aOR]: 2.03, 95% CI: 1.30–3.16, p = 0.002), showing 36.6% sensitivity, 78.8% specificity, 20.9% PPV, and 89.0% NPV. Infiltrative BCC significantly associated with ulceration extent (χ 2 =9.146, p = 0.027). Brown globules increased the likelihood of aggressive BCC (aOR: 2.21, 95% CI: 1.00–4.87, p = 0.049) and were significantly associated with micronodular BCC (χ 2 =12.681, p = 0.005; 19.0% vs. 4.5% in non‐micronodular lesions). Limitations Retrospective design, reliance on dermoscopic images, and lack of external validation. Conclusions Extensive ulceration and brown globules aid recognition of aggressive BCC subtypes, being associated with infiltrative and micronodular BCC, respectively.