Clinicopathological Features of Basal Cell Carcinoma of the Skin at Thammasat University Hospital

Background: Basal cell carcinoma (BCC) is one of the most common skin cancers that may result in local invasion and poor cosmetic appearance if left untreated or inadequately excised with tumor remaining in the surgical margin. BCC incidence rates are increasing but the number of studies from Thailand is limited. Objective: To study the clinical and histopathological features of BCC in Thailand and classify lesions as Low- or high-risk and determine factors associated with infiltrated surgical margins. Materials and Methods: This is a retrospective descriptive study that was conducted at Thammasat University Hospital, Thailand between January 2017 to September 2023. Results: A total of 75 excisional specimens were obtained from 71 patients of mean age 69 years and a male to female ratio of 0.64:1. Mixed and pure histological subtypes numbered 49 (65.3%) and 26 (34.7%), respectively, and nodular types predominated in both subtypes: 28/49 (57.1%) and 11/26 (42.3%). Four factors were associated with infiltrated surgical margins (p < 0.05): tumor size > 1.2 cm, tumor depth > 4.4 mm, tumor location in high-risk areas, and tumor invasion into subcutis or deeper levels. The latter was associated with high-risk subtypes (p < 0.001) whilst pigmentation was associated with low-risk subtypes (p < 0.05). Conclusion: Our data is broadly consistent with other case series. Preoperative evaluation to determine BCC subtype (low-/ high-risk), tumor depth, location, and level of invasion from punch or incisional biopsies should be performed to ensure adequate surgical excision and tumor free margins.