A Case Report of Cold Agglutinin Disease, Severe B12 Deficiency, and Pernicious Anemia: A Deadly Coincidence.

Anemia is the most common hematological disorder. It is commonly a manifestation of an underlying disease. Its causes are multifactorial, including but not limited to nutritional deficiencies, chronic conditions, inflammatory processes, medications, malignancy, renal dysfunction, hereditary diseases, and bone marrow disorders. We present a case of a patient exhibiting anemia related to cold agglutin disease and severe B12 deficiency secondary to pernicious anemia.