A 65-year-old man with metastatic pancreatic carcinoma shows elevated PT and aPTT, platelets 15x10^3/µL, and elevated D-dimer. A blood smear would show:

A 65-year-old man with metastatic pancreatic carcinoma shows elevated PT and aPTT, platelets 15x10^3/µL, and elevated D-dimer. A blood smear would show:

• A. Howell-Jolly bodies
• B. Macro-ovalocytes
• C. Schistocytes
• D. Target cells

Answer: (C)

In this scenario, the underlying issue is disseminated intravascular coagulation (DIC) triggered by advanced cancer. DIC causes widespread microthrombi formation in small vessels, which mechanically shear red blood cells as they pass through these narrowed, clot-filled microcirculations. That destruction produces fragmented RBCs called schistocytes on a blood smear. The lab pattern supports DIC: prolonged PT and aPTT from consumption of clotting factors, thrombocytopenia from platelet use, and elevated D-dimer from increased fibrin degradation. So the smear would show schistocytes. Other smear findings point to different conditions: Howell-Jolly bodies suggest splenic dysfunction; macro-ovalocytes indicate megaloblastic anemia; target cells are seen in liver disease, hemoglobinopathies, or post-splenectomy states.

In this scenario, the underlying issue is disseminated intravascular coagulation (DIC) triggered by advanced cancer. DIC causes widespread microthrombi formation in small vessels, which mechanically shear red blood cells as they pass through these narrowed, clot-filled microcirculations. That destruction produces fragmented RBCs called schistocytes on a blood smear. The lab pattern supports DIC: prolonged PT and aPTT from consumption of clotting factors, thrombocytopenia from platelet use, and elevated D-dimer from increased fibrin degradation. So the smear would show schistocytes.

Other smear findings point to different conditions: Howell-Jolly bodies suggest splenic dysfunction; macro-ovalocytes indicate megaloblastic anemia; target cells are seen in liver disease, hemoglobinopathies, or post-splenectomy states.