Squamous Cell Carcinomas metastasize primarily via the lymph system and the circulatory system. Given the places that they are likely to go to, the scalp is pretty unlikely. Even loco-regional spread from a lesion that has broken through from the oral cavity occurs, but I have never heard of that kind of spread very far away from the oral cavity. Nasopharyngeal SCC will spread up to the orbit of the eye, and these can move quite fast - but to the scalp? I wouldn't be looking for something there. Solar radiation induced carcinomas as an independent etiology could be encountered there, but I would expect to see others develop first such as basal cell carcinoma.

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.