A 34-year-old woman is evaluated because of progressive fatigue and recurrent attacks of abdominal pain. She weighs 61.2 kg (135 Ib). Her pulse rate is 110/min and her blood pressure is 110/70 mm Hg. She is pale, and her spleen is palpable 4 cm below the costal margin. Laboratory studies: Hemoglobin 6 g/dLHematocrit 20% Leukocyte count 2500/?L Platelet count 80,000/?L Reticulocyte count 10%Blood smear Anisocytosis and polychromatophilia Haptoglobin 0 mg/dLSerum lactate dehydrogenase 645 U/LThere is high level of hemosiderin in the urine.What is the most likely cause of this patients pancytopenia?
A)Autoimmune hemolytic anemia
B)Aplastic anemia
C)Myelodysplastic syndrome
D)Paroxysmal nocturnal hemoglobinuria
E)Acute myeloid leukemia

Question

Quizplus · Accepted Answer

Paroxysmal nocturnal hemoglobinuria (PNH) is the most likely cause of this patient's pancytopenia, given the combination of symptoms (fatigue, abdominal pain), findings (pale appearance, splenomegaly), and laboratory results (low hemoglobin, low leukocyte and platelet counts, high reticulocyte count, low haptoglobin, high lactate dehydrogenase, and high levels of hemosiderin in the urine). These findings suggest hemolysis, which is a hallmark of PNH.

A 34-Year-Old Woman Is Evaluated Because of Progressive Fatigue and Recurrent