Hello, You have a lump under the skin of your shin. It is hard, painless, immovable. You are always feeling fatigue and have lost a lot of weight without change of diet. You are suggested to get clinically examined by an GO or an oncologist. Get the required blood works, imaging tests, biopsy if needed, etc., done to detect if the lump is benign or malignant. You have not mentioned if the lump is growing or not. The treatment will depend on the report obtained. Sudden loss of weight is not a good symptom. You are feeling fatigued so avoid skipping meals, take home made nutritious diet. Stay away from anxiety and stress. In the meantime, make use of supportive measures like resting and leg elevation. If your shin lump lessens or goes away with these supportive measures, your condition is most likely not life-threatening. If detected malignant cancer, your physician will discuss treatment options including surgery, radiation or chemotherapy. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician