A 34-year-old woman presents to her physician with complaints of fatigue for the past 3 weeks. She reports heavy menstrual periods over the past several months, requiring her to change pads every hour during the first two days of her cycle. Her past medical history is significant for hypothyroidism, for which she takes levothyroxine. Her vital signs are as follows: temperature 98.6°F (37°C), heart rate 102 beats/minute, blood pressure 110/70 mmHg, and respirations 16/minute. Physical examination reveals pale conjunctivae and mild tachycardia but no hepatosplenomegaly or lymphadenopathy. Laboratory tests reveal the following results: hemoglobin 9.5 g/dL, mean corpuscular volume (MCV) 72 fL, serum iron 25 µg/dL, ferritin 10 ng/mL, total iron-binding capacity (TIBC) 450 µg/dL, and transferrin saturation 5%.
B) Iron deficiency anemia
Iron deficiency anemia is a microcytic anemia characterized by low iron and low ferritin levels, elevated total iron-binding capacity (TIBC), and low TIBC saturation (also known as transferrin saturation). This patient's laboratory findings are consistent with iron deficiency anemia, likely due to chronic blood loss from heavy menstrual periods. The presence of pale conjunctivae and mild tachycardia further supports the diagnosis of anemia.
Answer choice A: Anemia of chronic disease, is incorrect. Anemia of chronic disease typically presents with normal or elevated ferritin levels and low TIBC, which are not seen in this patient.
Answer choice C: Sideroblastic anemia, is incorrect. Sideroblastic anemia is characterized by ringed sideroblasts in the bone marrow and does not typically present with low ferritin and elevated TIBC.
Answer choice D: Thalassemia minor, is incorrect. Thalassemia minor is a microcytic anemia but typically presents with normal iron studies and is often associated with a family history of thalassemia.
Answer choice E: Vitamin B12 deficiency, is incorrect. Vitamin B12 deficiency typically causes macrocytic anemia, not microcytic anemia.
Key Learning Point
Iron deficiency anemia is a microcytic anemia characterized by low iron and low ferritin levels, elevated total iron-binding capacity (TIBC), and low TIBC saturation (transferrin saturation).
