A 29-year-old woman presents with fever, petechial hemorrhages, and confusion. Hemoglobin is 8 g/dL with a reticulocytosis, platelet count is 15,000/mm3, and creatinine is 1.8 mg/dL. The direct antiglobulin test is negative. Which abnormality on her peripheral blood smear best explains the anemia?

• A Spherocytes lacking central pallor
• B Fragmented red cells (schistocytes) ✓
• C Teardrop cells with nucleated red cells
• D Echinocytes with spiculated membranes

Explanation

The picture is thrombotic thrombocytopenic purpura, a microangiopathic hemolytic anemia in which red cells are mechanically sheared as they traverse platelet-rich microthrombi, producing helmet cells and schistocytes. The negative Coombs test distinguishes this from autoimmune hemolysis, where spherocytes predominate. Teardrop cells and nucleated red cells indicate marrow fibrosis or infiltration, not intravascular shearing, and echinocytes arise from uremia or membrane ATP depletion rather than mechanical fragmentation.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.