What Can You Tell Me About Tumors On The Spleen

What can you tell me about tumors on the spleen that may be malignant? Where do they usually begin? What is the treatment? I have a 54 yr. old retarded cousin, (cerebral palsy?), with 50+ lbs wt loss over the last 6 mos, now has bronchitis and uti. Has recently fallen and got small cut on head. Walking is not a problem generally. We know he cannot tell us if he is in pain because he doesn't understand what pain is. I need some guidelines. Any information we can get to help him with the proper care would be wonderful. Thank You.