Abstract
Basal cell carcinoma (BCC) is the most common human malignancy, accounting for the majority of all non-melanoma skin cancers (NMSC). In the past several decades the worldwide incidence of BCC has constantly been increasing. Even though it is a slow growing tumour that, left untreated, rarely metastasizes, it has a distinctive invasive growth pattern, posing a considerable risk for local invasion and destruction of underlying tissues, such as muscle, cartilage, bone or vital structures. Advanced BCCs include such locally invasive or metastatic tumours. Complete surgical excision is the standard therapy for most uncomplicated BCC cases with good prognosis and cure rates. Treatment of advanced forms of BCCs poses significant therapeutic challenges, most often requiring complicated surgery, radiotherapy, and/or targeted therapies directed towards the sonic hedgehog signalling pathway (SHH). We present two cases of large BCCs located on the scalp and posterior thorax, which underwent surgical excision with clear margins, followed by reconstruction of the defect after extensive undermining of the skin.