Is Still's disease still one disease? A case of Adult-onset Still's disease showing accumulation in the carotids and the large vessels of the legs on positron emission tomography: CT images.

Adult-onset Still's disease (AOSD) is known as a systemic inflammatory disease of unknown etiology and pathogenesis, characterized by fever, skin eruptions, systemic organ involvement, and arthralgias. AOSD is difficult to diagnose because of its heterogeneous clinical manifestations and prevalence (although more prevalent in the young, onset of AOSD after the age of 60 has also been described), and absence of pathognomonic clinical features. The disease also lacks a specific diagnostic test. To date, association studies between AOSD and HLA loci have failed to indentify a genetic predisposition. The recent publication of entirely different PET-CT manifestations found in three patients who were supposed to have the same disease (AOSD), as well as the surprisingly different PET-CT images of our AOSD patient (accumulation in the carotids and large vessels of the legs), raises our suspicion that AOSD is actually not one entity but a constellation of disorders whose varying underlying pathologies are now being revealed by new imaging techniques.