My Husband - 71 - COPD, Over Weight, Diabetes, Has

my husband - 71 - COPD, over weight, diabetes, has developed a swelling over the liver/stomach area just below the ribs. No pain at all, no fever, no "hot to touch". We have watched it for 3 days and it has grown larger. We contacted his doc (whom we love) and she asked about weight gain (he doesn't get on the scale), but with no other symptoms, it's almost a non-issue. About 4 years ago, he developed pleurisy on the same side and was in-patient for 18 days. I'm almost confident they are not related as he's having no pain or other symptoms. But it is a puzzlement. Do you have ideas? And thank you!