Abstract
INTRODUCTION: Vitamin B12 (cobalamin) is a crucial vitamin for blood precursor production, particularly erythrocytes. Its deficiency can lead to complications like severe anemia (Hb < 6 mg/dL) in 2.5% of patients and intramedullary hemolysis in 1.5%.
AIM: This case report aims to describe a rare presentation of pseudo microangiopathic hemolytic B12 deficiency anaemia in a 55-year-old male.
CASE DESCRIPTION: A 55-year-old diabetic male presented with long-standing abdominal pain, nausea, decreased appetite, malaise, fatigue, and tongue pain worsening over two weeks. Examination revealed scleral icterus, reddish-brown urine, decreased sensation on bilateral soles, abnormal gait, and no focal neurological deficits. On admission, the blood workup showed Hemoglobin 5.6 mg/dl, MCV 119fL, RDW 79fL, Platelets 82000/uL, WBC 7100/uL, LDH 3611 U/L, Haptoglobin <30mg/dL. Peripheral smear showed decreased RBCs, and macrocytic normochromic anisopoikilocytosis, including schistocytes, tear drop cells, hypersegmented neutrophils, and elliptocytes. Further blood workup revealed total bilirubin 6.2mg/dL, Direct bilirubin 0.8mg/dL, Serum creatinine 0.4mg/dL, Serum methylmalonic acid 42294nmol/L, Serum homocysteine 71nmol/L, Serum B12 <100pg/dL, Intrinsic factor antibody >96. This suggests intramedullary hemolysis due to B12 deficiency against TTP. The patient received 3 units of packed RBCs, improving Hgb to 9 g/dL. Intramuscular B12 daily for 4 days significantly improved the symptoms. She was discharged with weekly intramuscular B12 for 4 weeks, MCV was 98fL, and Total Bilirubin was 1.5mg/dL.
DISCUSSION: This case highlights the importance of considering B12 deficiency in patients with atypical manifestations, such as concurrent hemolytic and megaloblastic anemia. It can be a significant differential for microangiopathic hemolytic anemias like HUS/TTP. Timely intervention including intramuscular B12 supplementation improved the clinical symptoms and hemoglobin levels. Severe B12 deficiency should be considered a cause of hemolytic anemia to optimize patient outcomes.