A woman in her 50s with a right lower-eyelid yellow plaque presented with unremitting abdominal and back pain. Computed tomographic (CT) scan of the chest, abdomen, and pelvis demonstrated extensive infiltrative stranding from the thorax through the retroperitoneal space. Sclerotic changes in multiple osseous structures were noted. Idiopathic retroperitoneal fibrosis was diagnosed following biopsies. Prednisone and azathioprine were started. Biopsy of the lower-eyelid yellow plaque returned xanthelasma (Figure, A). Ureteral obstruction, chronic kidney disease, and lymphedema complicated her course. Azathioprine was stopped after 1 year. Prednisone was slowly tapered but she relapsed 3 years later. A second retroperitoneal biopsy exhibited fibroadipose tissue, foamy macrophages, and chronic inflammation with fibrosis. Azathioprine and prednisone were restarted. She required multiple surgeries for spinal stenosis and ureteral obstruction. Her kidney function continued declining. Then, owing to knee pain, a plain radiograph was obtained which demonstrated osteosclerosis of the distal femur. Consequently, the previous eyelid and retroperitoneal biopsies were reviewed. The clinicopathologic presentation was confirmed with a molecular test.