Anatomic distribution and temporal trends of malignant melanoma among 960 cutaneous malignancies managed over 22 years at a tertiary plastic surgery department

BACKGROUND: Melanoma, though less common than other cutaneous malignancies, remains clinically significant. In Asia, acral and nailunit melanoma-less related to ultraviolet exposure-pose diagnostic and reconstructive challenges. Clarifying temporal and anatomic trends in melanoma within plastic surgery practice may enhance early recognition and guide standardized reconstruction. METHODS: We retrospectively reviewed 960 surgically treated cutaneous malignancies (2000-2022) in a tertiary plastic surgery department, classifying tumors as basal cell carcinoma (BCC), squamous cell carcinoma (SCC), malignant melanoma (MM), or others. For MM, we analyzed anatomic site (head/neck, trunk, non-acral extremity, acral), sex, age, comorbidities, and lifestyle factors, comparing period A (2000-2017) with period B (2018-2022). Group comparisons used the chi-square or Fisher exact test and the Mann-Whitney test. Incidence rates were calculated with Poisson confidence intervals; between-period differences were evaluated using exact binomial tests and rate ratios. RESULTS: Of 960 tumors, BCC, SCC, MM, and others comprised 47.4%, 44.3%, 5.8%, and 2.5%. MM site distribution was heterogeneous: head/neck 14.3%, trunk 30.4%, non-acral extremity 21.4%, acral 33.9%. Distribution shifted significantly (chi-square p= 0.043), with head/neck lesions decreasing from 28.0% to 3.2% and trunk and acral lesions each increasing to 38.7%. Annual MM incidence rose from 1.39 to 6.20 cases per year (rate ratio, 4.46; p< 0.001). Hypertension (64.5%) and diabetes (35.5%) were more frequent in period B. CONCLUSION: Recent years showed a sharply increased MM caseload and redistribution toward trunk and acral sites with greater metabolic comorbidity, reflecting both epidemiologic change and evolving detection or referral patterns.