enlarged lymph glands, groin

Prelim diagnoses via ER two nights ago-- possible lymphoma. This arrived at due to CT scan indication of enlarged lymph nodes in abdomen. Possibly related med history: Recent, (April 22, 09), full knee replacement, am still in rehab/recovering. Lots of sweling/edema of affected leg. Swelling greatly reduced during twice weekly visits for physical therapy, but swelling comes back almost immediately/within an hour or so, (unless leg is in raised position of course). I am wondering if the swelling of the lymph glands might... might... be due to the ultrasound procedure to 'push' fluid back up leg and into groin? Have some, but nowhere near all the so called 'required set' of symptoms for lymphoma and have had most of those for several decades now, (26 years of mostly gastro-related problems, such as pain in abdomen, 'stomach dumping', bowel obstructions, nausea and so forth. Have also had 'breathlessness' and 'weakness' all those years as well, however no 'night sweats' nor 'itching' nor 'headaches' or some of the other classic symptoms of lymphoma). So could ultrasound treatment for leg edema conceivably irritate lymph glands in the groin area and cause them to swell as an associated effect of the movement of the fluid? Have to wait until July 7th or later for PET scan for further definition per lymphoma suspicion and in interim would sure like to know if this thought as attempted to articulate just above might have any merit/applicablility. Thank you.