Besides a blood clot, what can cause calf pain, burning in the back of the leg? 2 negative d dimers in december...I do have a fatty tumor on my back

Need in-person. Evaluation. It is not feasible to provide a meaningful opinion without examining you in-person. Is the pain on one side or both? Is there a swelling, redness, dilated vessels, varicose veins, skin rash? It would be prudent to see your doctor for an in-person evaluation.