About 18 months ago I discovered a semi hard lump on the outside of my shin bone. It feel like a bump but can only be felt on contraction of the muscle. The lump radiates pain whenever I go for walks or contract if for long periods of time. It doesn't appear to have grown but the pain has become more apparent. The lump also doesn't move and almost feels a bit like muscle tissue. I have been to see my GP on a few occasions with them verifying something was there but nothing has shown up on Xray or ultrasound in both showed nothing.
Other symptoms (could be completely unrelated) very hot at night this could be hormonal, I am 26 year old female.
In need of some advice or reassurance as I have read up on Sarcomas and as this does not feel fatty, doesn't move and has persisted for so long I am bit concerned.
From the description of your symptoms and findings, you most likely have a herniation of muscle through a fascial defect. These are very common. Since it is just normal muscle tissue protruding through the fascial defect, there is nothing "abnormal" to pick up on any studies.
The muscles in the leg are contained within compartments (four of them). The outside sheath of the compartment is called fascia. It is not uncommon for a small defect to occur in the fascia. Then, the muscle can herniate through the defect. The muscle is more likely to come through the fascial covering during or after exercise, because the muscle swells slightly from the increase in blood flow during exercise.
In some patients, when they squat, the bumps will appear up and down the anterior aspect of their shins. Some runners will have several of these muscle herniations.
There is no specific treatment for the fascial defects and muscle herniations. It is not recommended that the defect be closed, as this has led to the development of compartment syndromes.
If the patient is having increased discomfort in the muscle compartment during exercise, with the development of swelling, pain, numbness, tingling, then a release of the fascia can be done. In this case, the patient most likely has exertional compartment syndrome (not to be confused with traumatic compartment syndrome). The percutaneous release of the fascia usually takes care of the symptoms.
So, if you are having significant enough symptoms to affect your daily or exercise activities, then you should see an orthopedic surgeon. An orthopedic surgeon who is fellowship trained in sportsmedicine is probably the best to see, but any orthopedic surgeon can help you.