High-resolution CT findings of macrophage activation syndrome: a case report

Macrophage activation syndrome (MAS) is a rare disorder characterised by be nign, reactive, excessive, well-differentiated macrophage proliferation, se condary to an immune dysregulation in response to some triggering agents su ch as viral infection. We report a 3-year-old girl with MAS and pulmonary i nvolvement. This is the first radiographic description of MAS on high-resol ution CT.