A 43-year-old woman of Scandinavian descent complains of constant tiredness, light-headedness, and occasional palpitations and shortness of breath while ascending the stairs. Physical examination shows pallor of the oral mucosa and a raspberry-red tongue (glossitis). Neurologic examination reveals paresthesias, numbness, decreased vibration sensation, and loss of deep tendon reflexes. The results of laboratory studies include hemoglobin of 7.2 g/dL, WBC of 4,500/mL, platelets of 140,000/mL, erythrocyte folate of 220 ng/mL, serum vitamin B12 of 40 pg/mL (normal >200 pg/mL), serum anti-intrinsic factor of 1 :128, and serum anti-parietal cell antibody of 1 :64. Examination of peripheral blood shows macrocytic anemia, with poikilocytosis of RBCs and hyper segmented neutrophils. Atrophic gastritis is diagnosed by gastric biopsy. Bone marrow examination in this patient will reveal which of the following pathologic findings?
High-Yield Explanation
Pernicious anemia is an autoimmune disorder in which patients develop antibodies directed against gastric parietal cells and intrinsic factor. Parietal cell antibodies lead to atrophic gastritis with achlorhydria. Deficiency of vitamin B12 or folic acid results in megaloblastic anemia. The peripheral blood smear shows macrocytosis and hyper segmentation of neutrophils. Megaloblastic maturation, characterized by cellular enlargement with asynchronous maturation between the nucleus and cytoplasm, is noted in bone marrow precursors from all lineages. Although the bone marrow tends to be hypercellular, the blood demonstrates pancytopenia because of ineffective hematopoiesis. Neurologic symptoms develop in vitamin B12 deficiency, secondary to degeneration of the posterior and lateral columns of the spinal cord. The other choices are not seen in pernicious anemia.Diagnosis: Megaloblastic anemia, pernicious anemia