Histological spectrum of lip basal cell carcinomas: a retrospective study

OBJECTIVE: To characterize the histopathological subtypes of basal cell carcinoma (BCC) in the lip region, emphasizing common and rare morphological features and determining the proportion of high-risk tumors at this site. STUDY DESIGN: This study analyzed histopathological records of BCCs located in the lip and labial commissure regions in 3 Brazilian dental institutions. Demographic and clinical data were collected. Histopathological evaluation was independently performed by 3 oral pathologists and 1 dermatopathologist, with consensus reached when necessary. Tumors were classified according to contemporary histopathological criteria and stratified by risk based on World Health Organization guidelines. RESULTS: Among 68 lip BCCs, the upper lip was the most frequently affected site (52.9%). The nodular subtype was the most prevalent (52.9%) and predominantly classified as low risk. However, 45.6% of tumors were considered high risk, mainly due to aggressive variants, including micronodular and sclerodermiform patterns, and mixed histological subtypes. Ulcerated lesions tended to be high risk (68.4%; P = .07). Depth of invasion (mean 1.27 mm) showed a tendency toward greater infiltration in high-risk tumors (P = .05). CONCLUSION: Lip BCCs exhibit marked histopathological heterogeneity. Although low-risk nodular tumors predominate, a substantial proportion present high-risk features, reinforcing the importance of detailed histopathological assessment.