I can't seem to ever get an unequivocally clean scan. Grrr.
I recently had a PET scan, just routine, no symptoms. I get these scans done every three to four months to make sure I have not relapsed. On this one, in my chest, I have what the radiologist describes as a soft tissue mass in the anterior mediastinum. It has a concave edge and appears triangular. The mass took up the tracer with a SUV of 3.0 to 3.5, which is considered a modest amount of uptake. The radiologist said it was possibly thymic rebound. When I went in to see my oncologist, he said he looked at the scan himself and thought thymic rebound was likely due to the shape, location, and the moderate SUV level. So he said we can just watch it.
I asked him what a thymic rebound is. He said your thymus plays a role in your immune system when you are child, but when you reach adolescence, it has essentially served it's purpose and consequently begins to wither away until when you're an old and decrepit guy like him (haha) it is virtually undetectable. For some reason in younger people treated with chemotherapy or who have undergone a severe trauma, the thymus will sometimes start to grow again. He said thymic rebound is most common in children and younger adults (in their 20s or so). He said although not too much is known about it or what it represents, thymic rebound in a wide variety of cancers seems to be associated with a more favorable prognosis and long-term remission.
So I guess the last part is good. Of course, there is no way to know it is or isn't benign without actually going in and doing a biopsy, but fortunately he isn't suggesting that right now. So I guess I'll just sit tight and see what happens, like usual ...
