Knot On Head, Hard, Has Grown. Does Not Pain, No Skin Symptoms. What Can This Be?
Your question is a very good one and I will work on providing you with some good information and recommendations regarding what is going on. From the history which you have submitted so far it seems that you have experienced a degree of soft tissue swelling of the scalp which seems to be progressively getting larger albeit slowly.
I am assuming the remainder of your health is excellent and that you do not have any systemic symptoms such as fevers chills night sweats or unexplained weight loss or excessive fatigue. The most common cause of what you're describing is sebaceous cyst. These are soft tissue cysts which can be very firm to touch. These tend to form on areas of the body where there are hair follicles. Sometimes the hair follicles can become inflamed which causes the development of the cyst.
At the same time the symptoms you are experiencing cannot be ignored. I think it is extremely important that you visit with your doctor should also pay very close attention to the remainder of your lymph nodes. Lymph nodes are located under your arm in your groin as well as in your neck. Your doctor can examine these to make sure your lymph nodes are not enlarged.
What you are experiencing is highly unlikely to be any type of cancer or worrisome process. Again I would like to emphasize that you should have your doctor take a look at these areas in question. If you would like the ultimate degree of reassurance you might consider seeing a surgeon to have a small biopsy of one of these areas obtained. This will allow a pathologist to study these areas under the microscope to again reassure us that this is something that is benign.
I thank you again for submitting a question. I hope you have found my response to be informative and helpful. If you have any additional concerns please do not hesitate to ask.
Sincerely,
Dr. Robert