Thrombotic Thrombocytopenic Purpura: A Trojan Horse of Acute Leukemia?

Backgroud Thrombotic thrombocytopenic purpura (TTP) is a rare hematological disorder. The severity of TTP is associated with high mortality in the absence of treatment. Acquired TTP can be indicative of various underlying conditions, including neoplasia. Its identification is crucial because prompt management is essential. Case presentation We report the case of a 66-year-old male, a heavy smoker, who presented with drowsiness and confusion. One month before his presentation he presented a pruritic ecchymosis skin lesions, initially misdiagnosed as superinfected fungal lesions. Laboratory tests at the emergency department revealed bicytopenia (hemoglobin at 5.2 g/dL, platelets at 16,000) renal failure, and liver dysfunction disturbances. Further investigations confirmed microangiopathic hemolytic anemia, with a peripheral blood smear showing 3% schistocytes, hepatosplenomegaly, leading to a diagnosis of TTP. Urgent treatment with plasmapheresis was initiated. A bone marrow revealed acute myeloblastic leukemia (AML) type 2. ADAMTS13 levels were severely reduced, confirming TTP. Despite transient neurological improvement, the patient showed no significant biological response and passed away five weeks after diagnosis, highlighting the complexity and severity of his condition. Conclusion This case presents a rare instance of TTP as an initial presentation of AML, highlights the need to maintain a high clinical suspicion for neoplastic causes in atypical TTP. Although the association between AML and TTP is anecdotal, the unusual clinical features, including atypical skin lesions in a 65-year-old with constitutional symptoms, led to the AML diagnosis. The pathophysiology may involve anti-ADAMTS13 antibodies or ADAMTS13 deficiency. Treatment is based on standard TTP therapy (corticosteroids, plasmapheresis, Rituximab) while treating the underlying AML. A neoplasm, particularly a hematologic one, should be suspected in any elderly patient presenting with atypical TTP. Given the poor prognosis of both entities separately, their association remains fatal.