Would you offer definitive radiation therapy for a Merkel cell carcinoma in which surgical resection would be disfiguring or result in significant dysfunction?  

I would, but after an appropriate discussion. First, I favor full staging of all Merkel cell patients with a PET/CT (though many would argue this is not mandatory for small tumor, node-negative patients). I would also recommend a sentinel node procedure because the risk of nodal disease is significa...