What clinical or pathologic features would make you more concerned that a new skin SCC is from metastatic disease or a new cutaneous primary?  

Histologic examination should reveal an epidermal connection in a primary SCC. If one cannot be found, the pathologist must raise the possibility of a metastatic lesion and state that alternatively could be a portion of primary SCC (epidermal connection may not be included in biopsy sampling). If th...