Histological spectrum of lip basal cell carcinomas: a retrospective study

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.

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.

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).

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.