Thrombotic thrombocytopenic purpura: a Trojan horse of acute leukemia?: a case report.

BACKGROUND

Thrombotic thrombocytopenic purpura is a rare and life-threatening hematologic disorder. We present the case of a 66-year-old man who developed acquired thrombotic thrombocytopenic purpura as the first manifestation of acute myeloblastic leukemia. This case emphasizes the importance of considering underlying malignancy in atypical thrombotic thrombocytopenic purpura presentations.

CASE PRESENTATION: We report the case of a 66-year-old Lebanese male patient, a heavy smoker, who presented with drowsiness and confusion; 1 month before his presentation, he presented with pruritic ecchymosis skin lesions, which were 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 and hepatosplenomegaly, leading to a diagnosis of thrombotic thrombocytopenic purpura. Urgent treatment with plasmapheresis was initiated, and bone marrow aspirate demonstrated 27% myeloblasts consistent with acute myeloblastic leukemia with maturation (M2 subtype, according to the French-American-British classification). ADAMTS13 levels were severely reduced, confirming the presence of thrombotic thrombocytopenic purpura. Despite transient neurological improvement, the patient showed no significant biological response and passed away 5 weeks after diagnosis, highlighting the complexity and severity of his condition.

CONCLUSION

This case presents a rare instance of thrombotic thrombocytopenic purpura as an initial presentation of acute myeloblastic leukemia, highlighting the need to maintain a high degree of clinical suspicion for neoplastic causes in atypical thrombotic thrombocytopenic purpura. Although the association between acute myeloblastic leukemia and thrombotic thrombocytopenic purpura is anecdotal, the unusual clinical features, including atypical skin lesions in a 65-year-old patient with constitutional symptoms, led to the acute myeloblastic leukemia diagnosis. The pathophysiology may involve anti-ADAMTS13 antibodies or ADAMTS13 deficiency. Treatment is based on standard thrombotic thrombocytopenic purpura therapy (corticosteroids, plasmapheresis, and rituximab) while treating the underlying acute myeloblastic leukemia. A neoplasm, particularly a hematologic neoplasm, should be suspected in any elderly patient presenting with atypical thrombotic thrombocytopenic purpura. Given the poor prognosis of both entities separately, their association remains fatal.