Well since the location is not where HPV positive cancer is typically found I seriously doubt the virus is involved. Once the virus has invaded the cell, worse case it basically alters the reproductive cycle of the cell turning it to the dark side or cancer. The only way to determine if that cancer cell was invaded by HPV is to study and stain the cell looking for a specific protein. Other than other oral pre cancer conditions like leukoplakia I have never heard of any pre cancerous HPV positive SSC because I assume the virus is either killed off by our immune system (99% of the time) or converts the cell to cancer. Most/many HPV oral cancers are first discovered by a swollen lymph node and then traced back to the primary site which is usually the tonsils or the Base of Tongue.