Recurrent Strokes in a Woman with a History of Thrombotic Thrombocytopenic Purpura.

Thrombotic thrombocytopenic purpura (TTP) is a microangiopathy characterized by mechanical hemolytic anemia, resulting in end-organ damage. We describe a case of TTP which presented as an ischemic stroke. The patient presented with stroke as the primary manifestation of TTP despite a normal platelet count and mildly elevated lactate dehydrogenase level (LDH). The patient underwent two transfusions of fresh frozen plasma (FFP), and ADAMTS13 levels confirmed the diagnosis of TTP after discharge. This case demonstrates the importance of maintaining a high index of suspicion for TTP in the setting of normal laboratory values and reveals the many atypical manifestations of TTP.

Thrombotic Thrombocytopenic Purpura Triggered by Acute Myeloid Leukemia: A Case Report.

BACKGROUND Acute myeloid leukemia (AML) is a myeloid progenitor malignancy characterized by clonal expansion of immature blasts. Complications of AML can result from disease-related or treatment-related complications and commonly include bleeding and disseminated intravascular coagulation. Thrombotic thrombocytopenic purpura (TTP) is a microangiopathy syndrome characterized by a mechanical hemolytic anemia and a consumptive thrombocytopenia resulting in end-organ damage from thrombotic occlusion of small vessels. CASE REPORT We describe a case of TTP at our institution that developed after diagnosis of AML, an exceedingly rare phenomenon with only one such documented case in the current literature. We were advised to see this patient after development of renal failure and encephalopathy. Suspicion for TTP was initially low, as our patient had a low pre-test probability of TTP by the PLASMIC score. Our patient was treated for disseminated intravascular coagulopathy, without response. Plasma exchange pheresis (PLEX) was eventually begun 3 days after presentation upon result of ADAMTS13 activity at 10%, with presence of inhibitor. ADAMTS13 activity levels were used to guide continuation of PLEX, given our patient's persistent pancytopenia. CONCLUSIONS Our case demonstrates the challenges of identifying and managing TTP in patients with concomitant hematologic malignancies. ADAMTS13 activity levels should be collected in patients presenting with evidence of hemolytic anemia, even if the pre-test probability of TTP is low.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN): A promising future in the era of targeted therapeutics.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy arising from precursor dendritic cells. BPDCN cells characteristically express several markers on their cell surfaces including CD123, CD4, and CD56. Because of its rarity and challenging clinical presentation, there was no standard of care in managing BPDCN for decades and its prognosis overall was poor. However, as understanding of this rare neoplasm has increased, so have treatment options. The conventional cytotoxic chemotherapy regimens once used in the treatment of BPDCN were modest in their impact on disease relapse until paired with hematopoietic stem cell transplant. Although recent data suggest that there still remains a role for chemotherapeutic agents, targeted modalities have expanded the overall BPDCN treatment landscape. The CD123-targeted agent, tagraxofusp, was the first Food and Drug Administration-approved monotherapy in the treatment of BPDCN. Since its inception, several CD123-targeted and other cell-surface agents have been investigated, with many agents still in the preclinical stages. Although relapsed/refractory disease and central nervous system disease both remain formidable areas of research, there are several promising therapeutic approaches that could have a significant impact on the trajectory of treatment. This review will provide detailed insight on the novel drugs currently in use and those being explored in the management of BPDCN.