Hi Elizabeth,
I am sorry that I didn't respond to this sooner. Last year I had a root canal fail where a crack developed in one of the roots. An infection formed at the base of the root and vented through a fistula for quite some time before I had an oral surgeon extract the tooth. The fistula healed almost immediately. Fistulas are pretty normal occurances for infections in the root system. I went through several courses of antibiotics also with varying results. The lumps under your arm are probably a response to the infection.

There was no relation between my cancer and the fractured tooth. I am grateful that the tooth failed BEFORE the cancer however.