# Teledermatology and face-to-face pathways for basal cell carcinoma diagnosis in a southern European cohort: a comparative histopathologic analysis

## TL;DR

Teledermatology leads to the diagnosis of shallower basal cell carcinomas compared to in-person consultations, suggesting earlier detection.

## Contribution

This study is the first to compare histopathologic features of BCCs diagnosed via teledermatology versus face-to-face consultations in a southern European cohort.

## Key findings

- Teledermatology was associated with significantly shallower tumor depth compared to face-to-face consultations.
- Nodular and micronodular BCC subtypes were more common in teledermatology cases, while superficial and sclerodermiform subtypes were more frequent in face-to-face cases.
- Tumor depth was the only independent predictor of consultation pathway, indicating a consistent trend across subtypes.

## Abstract

Teledermatology has expanded markedly in the post-pandemic era; however, its impact on the histopathologic presentation of basal cell carcinoma (BCC) remains insufficiently characterized. Tumor depth and histologic subtype are key prognostic factors and may differ according to diagnostic pathway.

We conducted a retrospective observational study at a tertiary referral hospital in southern Europe, including all histologically confirmed BCCs diagnosed in 2019 through face-to-face dermatology and in 2022 through teledermatology. A total of 486 tumors were analyzed (201 face-to-face; 285 teledermatology). Histologic subtypes (superficial, nodular, micronodular, sclerodermiform) were examined individually and grouped into non-aggressive (superficial/nodular) versus aggressive (micronodular/sclerodermiform) categories. Statistical analyses included Welch’s t-test, chi-square tests, and multivariable logistic regression.

Mean tumor depth was significantly lower in the teledermatology cohort (1.67 mm vs. 2.51 mm; p < 0.001). Histologic subtype distribution differed between pathways (χ2 = 41.3; p = 0.002): superficial BCCs were more frequent in face-to-face consultations (15.9% vs. 8.8%), whereas nodular and micronodular variants predominated in the teledermatology group (65.6% vs. 62.2 and 13.3% vs. 4.0%, respectively). Sclerodermiform tumors were slightly more common in face-to-face evaluations (17.9% vs. 12.3%). When regrouped into non-aggressive versus aggressive patterns, the distribution differed between pathways, although this categorization did not indicate a predominance of low-risk histology in the teledermatology cohort. In multivariable analysis, tumor depth was the only independent predictor of consultation pathway (β = −1.10; p < 0.001).

Teledermatology was associated with the diagnosis of significantly shallower BCCs, even across subtypes, supporting its role in facilitating earlier histologic detection. Subtype differences were pathway-specific but did not fully account for the depth disparity. These findings highlight teledermatology as an effective diagnostic route for timely identification of BCC in contemporary clinical practice.