Atypical giant cell arteritis predominantly involving intramural coronary arteries: a case showing refractory dialysis-related hypotension.

Giant cell arteritis involving intramural coronary artery branches is rare, and its clinical features remain poorly understood. We report a 56-year-old hemodialysed patient with a history of mitral valve replacement, who presented with "fever of unknown origin" and intractable hypotension. The antemortem diagnosis was very difficult and the autopsy revealed giant-cell-rich vasculitis in arteries in multiple organs. The heart was most severely involved, in which almost all of the intramural coronary artery branches were infiltrated by many multinucleated giant cells, macrophages, and lymphocytes with luminal narrowing, but the epicardial segments of the coronary arteries were spared. Superimposed on the preexisting valvular heart disease, the vasculitic lesions were thought to play a central role in severe cardiac dysfunction resulting in dialysis-related hypotension, which led to fatal non-occlusive mesenteric ischemia. This case highlights the possibility that giant cell arteritis of intramural coronary arteries could be an uncommon underlying cause of refractory dialysis-related hypotension.