Poster Presentation New Zealand Association of Plastic Surgeons Annual Scientific Meeting

Metastatic BCC – A rare outcome in a common malignancy. Case series and literature review (1557)

Maxim Devine 1 , Mark Edmondson 1 , Vachara Niumsawatt 1
  1. Plastic and Reconstructive Surgery , Peter MacCallum Cancer Centre , Melbourne , Victoria , Australia

Basal Cell Carcinoma (BCC) is the most common cancer in Australia, representing 80% of non-melanoma skin cancers. Metastatic BCC is very uncommon (incidence up to 0.0028%) so few clinicians have experience with managing this disease. Methodology: We performed a literature review of metastatic BCC in light of two cases referred to our specialist tertiary cancer centre in 2022. Results: Case 1: 65 year old man with T3 infiltrative BCC of the scalp with perineural invasion (PNI) excised with clear margins 2 years prior. A right level V neck mass was noted on ultrasound with features suggestive of a sebaceous cyst. Excisional biopsy revealed a subcutaneous deposit of metastatic BCC with invasion of a single lymph node. Selective neck dissection was performed with no further metastases in 24 lymph nodes followed by adjuvant radiotherapy. Case 2: 83 year old man on cemiplimab for multiple unresectable cutaneous Squamous Cell Carcinomas (SCC) developed an enlarged PET-avid axillary node, favoured to be SCC, on fine needle aspiration cytology. After 10 months of immunotherapy, the node failed to respond and repeat biopsy was suggestive of BCC, with an overlying cutaneous lesion noted. Axillary lymphadenectomy found 2/14 nodes involved with metastatic nodular BCC with PNI. The patient continued cemiplimab treatment without complication. Conclusion: Clinicians should maintain an index of suspicion for the occurrence of metastatic BCC, particularly when the working diagnosis is not concordant with clinical and radiological findings. The role for nodal clearance, adjuvant radiotherapy, and hedgehog pathway inhibitors in this setting warrants further study.