A case series of atypical presentations of thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is a heterogeneous disease primarily characterized by thrombocytopenia and microangiopathic hemolytic anemia. Therapeutic plasma exchange has dramatically improved mortality, allowing for emergence of refractory, relapsing, and atypical presentations. In this article, we describe four cases of TTP presenting with minimal schistocytes, mild elevation of lactate dehydrogenase, and symptoms suggestive of macrovascular arterial involvement. With increasing reports of less common presentations of TTP, clinicians should consider this diagnosis in cases of unexplained arterial thrombosis, thrombocytopenia, or hemolytic anemia. Testing for a disintegrin and metalloprotease with thrombospondin Type 1 motif, Member 13 ADAMTS13 activity was extremely useful to help confirm the diagnosis in our series of patients.