Insights into basal cell carcinoma with bone metastasis: a comprehensive review

Basal cell carcinoma (BCC), the most common skin cancer worldwide, is closely associated with sunlight exposure and generally exhibits a low metastatic potential, with a frequency ranging from 0.0028% to 0.55%. Despite its rarity, BCC with bony metastases causes important clinical complications. We collected information on published patients with a diagnosis of BCC with bony metastases, and examined patient demographics, tumour characteristics, histological features and treatment modalities to define patterns and outcomes. Our study encompassed 108 patients: 68 men and 40 women with a mean (SD) age of 66.9 (6.4) years. Histologically identified subtypes included 42 nodular, 28 infiltrative, 9 morphoeaform, 5 metatypical and 1 superficial BCC, with 23 patients having a mixed histopathology pattern. The main treatments were -surgery (n = 98), chemotherapy (n = 31), immunotherapy (n = 16) and radiotherapy (n = 34). BCC with bone metastases, although rare, requires more attention due to the complexity of management. Histological subtypes such as infiltrative, sclerosing, morphoeaform, basosquamous and micronodular are associated with aggressive behaviour and the detection of symptoms such as bone pain or hypercalcaemia in patients at high risk of metastasis is important for timely diagnosis. Because of the aggressive potential and clinical implications of some subtypes, a personalized management approach with comprehensive histological and molecular profiling is essential to optimize outcomes in patients with BCC with bone metastasis.