Thank you very much for your input. It is very good news that you don't have any of the above symptoms and conditions.Actually, the place on the head where this lump is located is not very unusual and there are different structures which may be present here.
For example , LYMPH NODES, and if they are stony hard they might indicated either a local cancer or indicate spread of a distant cancerous lesion.But , if like that , they are most likely accompanied by loss of weight, generalized weakness, etc.Likewise if the lump here is rubbery hard might indicate infection , but likely to be accompanied by fever, etc.
I think , the lump you have might be an OSSIFYING fibromas , i.e. it could be collection of fibrous tissue with core bony material attached to your skull hence hard.Such lumps are very rarely cancerous , especially if they are NOT growing also.They can be removed through simple surgical procedure and sent for biopsy if needed.One more possibility is sebaceous or epidermal cyst, which is actually part of the follicle containing hair, sebum etc.But for this lump, this place and such consistency is unusual .
You should see your physician or a surgeon and i believe it is more likely to be an ossifying fibroma.
General symptoms of almost all cancers are fatigue, weight loss, generalized weakness , and the a number of other symptoms depend upon the location and the structures, cancer affects.Like cancer of the brain accompanies symptoms of convulsions, weight loss fatigue,vision problems, weakness of the corresponding limbs loss of memory, personality changes, and severe headaches.
What i want to impress upon you is the possible condition you could be having. Unfortunately , without , having first hand examination of the patient or client , leaves you with too much space and i don't think an online discussion can replace a true doctor -patient relationship. This discussion should be duly taken as informative , but to ascertain the exact cause , you should see your physician.
God bless Hope i have answered your question.