[Pancreatic cytosteatonecrosis].

If cutaneous panniculitis, made of dermo-hypodermic nodules, is the most constant manifestation of pancreatic cytosteatonecrosis, articular and bony localizations are quite frequent and sometimes the first manifestation of the disease. Articular lesions: monoarthritis, oligo-arthritis and mostly polyarthritis, often assume a very inflammatory picture; the synovial fluid is oily or puriform, and has a high content of polynuclear cells or macrophages with a foamy cytoplasm, lipid droplets, triglycerides, non-esterified fatty acids, and pancreatic enzymes; the most typical synovial lesion is a cytosteatonecrosis with adipocytes showing a huge lipidic vacuole. The bony lesions are mostly osteolytic, microgeodic lesions, or more extended ones, pseudo-tumoral without soft tissue invasion: more rarely, there is a periosteal thickening, bony infarctions, or epiphyseal osteonecrosis; these lesions do not always demonstrate a hyperfixation on scintigrams. The physiopathology of these various lesions is usually linked to a diffusion of pancreatic lipases, but other enzymes or enzymatic inhibitors also intervene, as well as a cytotoxic and local inflammatory activity of the fatty acids themselves. Surgical treatment of the pancreatic lesions, when possible, is the only treatment that is truly effective.