Microangiopathic haemolytic anaemia and thrombocytopenia due to combined vitamin B12 and folate deficiency masquerading as thrombotic thrombocytopenic purpura.

Vitamin B12 deficiency and folate deficiency are common causes of macrocytic anaemia and both are important for many cellular processes. These deficiencies could be due to inadequate dietary intake, impaired absorption or drug ingestion. We present a case of a 47-year-old male with a history of diffuse large B-cell lymphoma (DLBCL) who was admitted for fatigue, persistent frontal headache and left upper-quadrant abdominal pain. Further investigation showed that he had pancytopenia with microangiopathic haemolytic anaemia (MAHA) and intracranial bleeding (ICB). Serum vitamin B12 and folate were later found to be low and a diagnosis of combined vitamin B12 and folate deficiency mimicking thrombotic thrombocytopenic purpura (TTP) was made. The patient responded well to vitamin B12 and folate replacement.