Hello Dr. Bhatti - yesterday I found a hard knot in the mastoid region. I am 41 and on no medications and all prior CBC screenings have always been normal. I do suffer from chronic fatigue and headaches . I have not had any recent illnesses or ear infections of any sort. The only ongoing symptom is fatigue. Please explain if these nodules tend to weigh on the side of harmless or more likely a serious condition that needs medical attention and also what your experience has been in the realm of diagnosis.