Could you clarify that you have had this biopsied? It doesn't sound like you have, particularly on the current timescale you intimated. That is the only way to

Could you clarify that you have had this biopsied? It doesn't sound like you have, particularly on the current timescale you intimated. That is the only way to know for sure if it's cancerous (I've got first hand experience). I'm not saying don't worry about it, but 'probably cancerous' doesn't sound like a biopsy report and that is needed first as that's the only way to tell. Keep a cool head, take the precautions the others are recommending here regarding your medical cover (God bless the USA) and get some confirmation of what the lump is before you move on.