Your total leukocyte count, ESR and ultrasound are normal; you have no lymph nodes and there are absolutely no symptoms - I wonder what made you think of lymphoma! Please be reassured that there is nothing at all to suggest a lymphoma. Swelling in the armpit can be due to any number of reasons, with a local infection being most likely. The surest way to diagnose a lymphoma is to biopsy the enlarged lymph node. There is no cause for concern and try to engage yourself in some sport or hobby rather than dwell needlessly on medical conditions.