[Macrophage activation syndrome revealing colon carcinoma About a case].

Macrophage activation syndrome is a state of hyper-inflammation that results from increased secretion of proinflammatory cytokines, responsible of the inappropriate activation and proliferation of cells from the lymphohistiocyte lineage. It associates clinical signs, biological abnormalities and images of haemophagocytosis. It is a rare but serious attack, that can be "primary" or "secondary" to an infection, neoplasia, or autoimmune disease.