RESUMO
Although thrombotic thrombocytopenic purpura (TTP) is rare, early diagnosis and treatment are important for decreasing the mortality rate. Acquired vitamin B12 deficiency is frequently overlooked because of its rarity in developed countries, particularly in children and adolescents. The hematological changes in vitamin B12 deficiency present as megaloblastic anemia, increased lactate dehydrogenase, vasoconstriction, increased platelet aggregation, and abnormal activation of the coagulation followed by microangiopathy as well as neutropenia and thrombocytopenia. We report herein the case of a 15-year-old girl who had been neglected, which might have caused pseudo-TTP through malnutrition, particularly vitamin B12 deficiency. When we encounter cases of TTP in children, clinicians must be aware of the possibility of malnutrition, particularly with vitamin B12 deficiency, even in developed countries, and investigate the cause of malnutrition including neglect.