Thrombotic Thrombocytopenic Purpura: Revisiting a Miss and an Inevitable Consequence.

Thrombotic thrombocytopenic purpura (TTP) is typically characterized by the symptomatic pentad of fever, thrombocytopenia, microangiopathic hemolytic anemia, neurologic abnormalities, and renal failure. Atypical TTP is the diagnosis used to describe the subset of patients with TTP who present with symptoms that deviate from the classic pentad. We report a case an 86-year-old woman who presented to the emergency department complaining of chest pain for one day. She was reportedly on antibiotics for sinus infection. Physical examination revealed multiple bilateral superficial hematomas, predominantly on her extremities. On admission, her lab values were as follows: platelet count of 6,000/cubic millimeter, hemoglobin of 10.4 grams/deciliter, leukocyte count of 5100 cells/cubic millimeter, total bilirubin of 2.3 milligrams/deciliter, and troponin-I of 5.190 nanograms/milliliter. Peripheral blood smear was normal and did not reveal any schistocytes. The patient was admitted to the intensive care unit with a diagnosis of a non-ST-elevation myocardial infarction and a presumed diagnosis of immune thrombocytopenic purpura from antibiotic use. She was treated with intravenous solumedrol and a high-intensity statin. On the third day of her admission, the patient's mental functioning deteriorated and was intubated to protect her airway. A second peripheral smear revealed schistocytes, and subsequent laboratory studies supported the diagnosis of TTP. Plasma exchange therapy was planned. However, the patient succumbed to cardiac arrest before it could be initiated. The diagnosis was later confirmed with an ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) assay.  This case serves as an example of one of the many ways in which TTP can present, and emphasizes the importance of considering TTP as a differential diagnosis.