Keywords: Epidemiology; Surveillance; adenoid cystic carcinoma; and End Results; apocrine adenocarcinoma; cutaneous adnexal tumors; cutaneous appendageal carcinoma; eccrine adenocarcinoma; epidemiology; hidradenocarcinoma; incidence; malignant mixed tumor; microcystic adnexal carcinoma; porocarcinoma; sebaceous adenocarcinoma; sebaceous carcinoma; skin cancer; spiradenocarcinoma; trends.