Discrepancies between biopsy and formal excision histology of non-melanoma skin cancer

Upstaging of basal cell and squamous cell carcinomas during definitive surgery: a review of predictive preoperative clinical and histologic features

The incidence of nonmelanoma skin cancer (NMSC) in the United States is increasing with approximately 3.6 million cases diagnosed per year. The staging and treatment of NMSC is guided by histologic subtype based on skin biopsy, along with other tumor-specific factors. However, a biopsy only represents a portion of the tumor, so there is a risk of upstaging at the time of definitive surgery. We conducted a review of the literature and found that a significant proportion of NMSC were upstaged during surgery. The rate of upstaging of basal cell carcinoma (BCC) was 7-31% and that of squamous cell carcinoma in situ (SCCIS) to squamous cell carcinoma (SCC) was 3-39%. Biopsy sampling error and variability in interpreting and reporting by dermatopathologists contribute to these discrepancies. It is pertinent to consider more comprehensive treatment modalities for tumors at high risk for upstaging. Diligence to identify tumors at higher risk for upstaging will allow clinicians to optimize management.