Purpose
Giant basal cell carcinomas (GBCC), defined as >5cms, account for <1% of all BCCs diagnosed. Characteristics include; locally aggressive behaviour, recurrence and higher rates of metastasis. Lesions >10cm are associated with a 45% mortality rate. Associated risk factors include; recurrence post treatment and high-risk subtypes. With no clear guidelines due to the condition rarity, analysis of risk factors, aetiology and treatment options was required.
Methodology:
A retrospective case series of 5 patients with GBCC, collected over a 2-year period from the Royal Brisbane and Woman’s and Rockhampton Hospitals, in Queensland Australia. Data collected from medical records included; demographic information, aetiology, risk factors and treatments received. A systematic literature search of Medline and PubMed databases was conducted to review available treatment options.
Results:
3 men and 2 women were analysed. Wide local excision was utilised in 3 cases with reconstruction involving; 2 Pectoralis Major flaps and 1 VRAM. Common factors among patients included; neglect, delayed presentation and 4/5 had a mental illness. Vismodigib, a Sonic Hedgehog Inhibitor, was used in 1 patient with recurrent disease. It inhibits Smoothened, a transmembrane protein relevant in more than 90% of GBCCs. Indications include; advanced disease where surgery or radiotherapy are not suitable. 3-month treatments have shown clear reductions in tumour size.
Conclusions:
GBCC are rare, with limited guidelines for treatment. Mental illness can delay treatment with poorer outcomes. Effective results have been achieved with single stage reconstructions. However, Vismodigib is an emerging therapy that improves prognosis and surgical candidacy while reducing surgical morbidity.