What the Hell is a "Mediastinum"?

Two days after the lymph nodes on the left side of my next popped out, I was back at the Dr's office, this time seeing another PA. She was young and seemed fairly new but also very competent. As I described my symptoms again, she asked me a bunch of new questions and didn't seemed particularly thrilled with the answers. She didn't say as much but here body language was a giveaway. She ordered up a more thorough round of blood tests, a urine analysus, and a chest x-ray. All of this was done in house so we could get immediate analysis of the x-ray.

To my surprise, there were some concerns with the x-ray. She said my mediastinum was showing signs of enlargement. My what? At this point, I've heard a lot of medical terms but that one was completely new to me. She explained that it is the "mass of flesh" in the chest that includes the heart, blood vessels, esophageus, and lymph nodes. It could be enlarged due to infection but since I was showing no other symptoms of upper respiratory issues (coughing, congestion, etc) it could also be something more deviant. She consulted with another doctor and the recommended getting a CT scan of my chest. Since that is an extremely expensive test ($1700) and it would have been entirely out-of-pocket, we agreed to run a course of 5-day antibiotics to see if that cleared things up and to follow up with the doctor after that.

Then I went home and Googled "mediastinum" and began to freak out a little bit. nearly every link involving mediastinum and enlargement referred Hodkin's lymphoma. This was the Friday before Thanksgiving and I was unable to set a follow up appointment with the other doctor until the Monday after Thanksgiving. This prove to be a LONG week of sleepless nights and Google research. When I complete the antibiotics the day before Thanksgiving and my symptoms had not changed, I really began to worry. Worst Thanksgiving weekend ever.