Search

Simple Summary: Due to their high incidence, thin melanomas represent a significant portion of all melanoma-related deaths (30%). In this retrospective case–control study, metastasizing thin melanomas (≤0.8 mm) showed at least one atypical clinical–dermoscopic feature (diameter > 10 mm, at least three colors, regression structures, atypical vascular pattern and absence of a pigment network) and at least one conventional adverse histopathological feature (regression, dermal mitoses, vertical growth phase and ulceration). In thin melanomas, the identification of specific clinical–dermoscopic features (statistically significant) coupled with adverse histopathological features may suggest an early detection of potentially metastatic patients who require prolonged and close monitoring. Despite being early-stage tumors, thin cutaneous melanomas contribute significantly to mortality and have a rising incidence. A retrospective case–control study was performed to identify clinical–dermoscopic and histopathological variables linked to local and distant metastases in melanomas ≤0.8 mm. Data from 1 January 2000 to 22 June 2022 were analyzed from two Italian skin cancer referral centers. Sixteen patients with ≤0.8 mm melanomas developing metastases were studied compared to controls without metastases over 5 years. Statistical analysis involved Pearson's chi-squared test or Fisher's exact test. Of the 1396 cases, 1.1% progressed. The median diagnosis age was 49 (range 28–83), with 56.3% men and 43.7% women. The torso was the primary tumor site (43.7%). Clinically, lesions were pigmented (>10 mm diameter: 73.3%, ≥3 colors: 80%). Dermoscopically, the common features were white patches (73.3%), atypical vascular patterns (66.5%), blue-gray areas (60%) and absent pigment networks (60%). Histopathologically, all cases had adverse features like regression (87.4%), dermal mitoses (50%), a vertical growth phase (62.5%) and ulceration (12.5%). These findings were statistically significant compared to controls (p < 0.05). In ≤0.8 mm melanomas, specific clinical–dermoscopic traits might indicate higher metastatic potential when paired with adverse histopathological features. [ABSTRACT FROM AUTHOR]