Atypical presentations of thrombotic thrombocytopenic purpura: a review.

Thrombotic thrombocytopenic purpura (TTP) is diagnosed by the presence of microangiopathic hemolytic anemia and thrombocytopenia in a patient who frequently presents with central nervous system involvement and, to a lesser extent, renal dysfunction. Recent understanding of the pathophysiology of TTP due to severe deficiency of von Willebrand factor cleaving protease, known as ADAMTS13, has improved diagnosis of TTP. Once the diagnosis is suspected, life-saving therapeutic plasma exchange therapy is initiated. Occasionally, an unusual clinical presentation makes TTP diagnosis difficult, thus resulting in a delay in the management of TTP. This review highlights a variety of atypical TTP presentations described in the literature. It is intended to bring unusual scenarios to the clinician's awareness, so that timely treatment can be delivered. (c) 2008 Wiley-Liss, Inc.