Abdominal mass Definition An abdominal mass is swelling in one
part of the belly area (abdomen). Mass in the abdomen An
abdominal mass is usually found during a routine physical
examination. Most of the time the mass develops slowly. You may
not be able to feel the mass. Finding where the pain occurs
helps the doctor make a diagnosis. For example, the abdomen is
usually divided into four areas: Other terms used to find the
location of abdominal pain or masses include: Epigastric --
center of the abdomen just below the rib cage Periumbilical --
area around the bellybutton The location of the mass and its
firmness, texture, and other qualities can provide clues to its
cause. Common Causes Abdominal aortic aneurysm can cause a
pulsating mass around the navel. Bladder distention (urinary
bladder over-filled with fluid) can cause a firm mass in the
center of the lower abdomen above the pelvic bones. In extreme
cases it can reach as far up as the navel. Cholecystitis can
cause a very tender mass that is felt below