A 32-year-old woman comes to the office due to worsening fatigue and exercise intolerance. She has no history of blood disorders. Physical examination shows mild mucosal pallor. Hemoglobin is 7.8 g/dL. Peripheral blood smear is shown in the image below. Which of the following is the most likely cause of this patient's anemia?

Question

A 32-year-old woman comes to the office due to worsening fatigue and exercise intolerance.  She has no history of blood disorders.  Physical examination shows mild mucosal pallor.  Hemoglobin is 7.8 g/dL.  Peripheral blood smear is shown in the image below.  Which of the following is the most likely cause of this patient's anemia?

Quizplus · Accepted Answer

11ec160b_3af2_4574_9249_370e34525228_MD0001_00 This patient with symptomatic anemia (eg, fatigue, exercise intolerance) has peripheral blood smear findings that indicate hemolytic anemia, including the following: Increased reticulocytes: Reticulocytes are larger than mature red blood cells (RBCs), lack central pallor, and have a bluish coloration (polychromatic RBCs) due to the presence of ribosomes, which are not found in mature RBCs. Increased reticulocytes in the peripheral blood is a nonspecific finding that indicates the bone marrow is responding appropriately to anemia by increasing production of new erythrocytes. Spherocytes: Spherocytes are erythrocytes with reduced cell membrane, which makes the cell spherical rather than biconcave. In otherwise healthy individuals, spherocytes generally arise in the setting of immune-mediated hemolytic anemia; in this condition, IgG-coated erythrocytes are partially phagocytized by splenic macrophages, which reduces the surface area of the erythrocyte cell membrane, thereby causing the erythrocyte to assume a spherical shape. Nucleated erythrocytes: Nucleated erythrocytes are very immature RBCs. The presence of nucleated RBCs in the peripheral blood indicates a strong bone marrow response to compensate for the anemia. (Choice A) Anemia due to erythropoietin deficiency is often seen in patients with end-stage renal disease because erythropoietin production by the kidneys is impaired. Individuals with erythropoietin deficiency are not able to sufficiently increase erythrocytosis in response to anemia; therefore, peripheral blood smear does not typically show increased reticulocytes or nucleated RBCs. (Choice C) Iron deficiency anemia can be seen in young women with heavy menstruation or gastrointestinal bleeding. However, peripheral blood smear typically shows hypochromatic RBCs and microcytosis. (Choice D) Thrombotic microangiopathy is associated with microvascular clot formation, which causes anemia via RBC shearing. In this condition, peripheral blood smear typically shows schistocytes, not spherocytes. (Choice E) Vitamin B₁₂ deficiency is common in patients with atrophic gastritis and alcohol use disorder. It commonly causes macrocytic anemia with hypersegmented neutrophils on peripheral blood smear. Educational objective: In patients with hemolytic anemia, peripheral blood smear usually reveals evidence of reticulocytosis, spherocytes, and nucleated red blood cells.

A 32-Year-Old Woman Comes to the Office Due to Worsening