Vitamin B12 malabsorption and pseudo- thrombotic microangiopathy in an adolescent

Thrombotic microangiopathies (TMAs) are a group of rare disorders that can be considered life threatening. The hallmark of this disease is a microangiopathic hemolytic anemia associated with thrombocytopenia which could be congenital or acquired. Acquired vitamin B12 deficiency is overlooked in developed countries but if severe, can mimic a TMA. We report the case of 17-year-old male with celiac disease who presented with a week of fatigue and jaundice. Initial evaluation revealed pancytopenia and hemolysis with a preliminary differential concerning for a myelodysplastic process or a thrombotic microangiopathy. There was no evidence of renal failure, or neurological changes and his hemoglobin stabilized with transfusion therapy. Subsequent bone marrow testing confirmed absence of malignancy or infiltrative processes. B12 levels were found to be undetectable and once replaced his signs and symptoms resolved. Replacement supported the diagnosis of a Vitamin B12 deficiency induced pseudo-thrombotic microangiopathy. When faced with a clinical presentation of a TMA in a child or an adolescent patient, physicians must be aware of the possibility of vitamin B12 deficiency especially in patients at risk for malabsorption.