Case series of three adult patients with exceptional clinical presentations of haemophagocytic lymphohistiocytosis.

Macrophage activation syndrome (MAS) is a secondary form of haemophagocytic lymphohistiocytosis (HLH). MAS-HLH is an underrecognised and life-threatening condition associated with a heterogeneous group of diseases including connective tissue disease and inflammatory disorders. Here, we report three cases of adult patients with MAS-HLH triggered by different entities, including systemic lupus erythematosus, Griscelli syndrome type 2, and Adult onset Still's disease.