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Difficulty: MediumHematology and Oncology

Match each clinical presentation and coagulation profile with the most likely underlying hematologic diagnosis.

  • A 22-year-old woman with a history of heavy menses presents with recurrent epistaxis. Labs show normal PT, prolonged aPTT, normal platelet count, and prolonged bleeding time.von Willebrand disease
  • A 14-year-old boy develops severe knee hemarthrosis after a minor fall. Labs show normal PT, prolonged aPTT that corrects with a mixing study, and normal platelet count.Hemophilia A
  • A 68-year-old man in the intensive care unit with gram-negative sepsis begins oozing blood from his intravenous catheter sites. Labs show prolonged PT, prolonged aPTT, thrombocytopenia, and elevated D-dimer.Disseminated intravascular coagulation (DIC)
  • A 75-year-old man on chronic oral therapy for atrial fibrillation presents with hematuria. Labs show a significantly prolonged PT, normal aPTT, and normal platelet count.Vitamin K antagonist effect
  • A 28-year-old woman with a history of recurrent spontaneous abortions presents with a deep vein thrombosis. Labs show normal PT and a prolonged aPTT that fails to correct with a mixing study.Antiphospholipid syndrome (Lupus anticoagulant)

Answer

Presentation 1 matches von Willebrand disease, 2 matches Hemophilia A, 3 matches DIC, 4 matches Vitamin K antagonist effect, and 5 matches Antiphospholipid syndrome.
Correctly identifying hematologic disorders requires integrating clinical signs (mucosal vs. joint bleeding, thrombosis vs. hemorrhage) with specific laboratory patterns. von Willebrand disease alters bleeding time and mucosal hemostasis. Hemophilia A causes isolated intrinsic pathway defects (prolonged aPTT) with deep joint bleeding. DIC globally consumes both platelets and factors. Vitamin K antagonists primarily affect the extrinsic pathway (isolated prolonged PT initially). Antiphospholipid syndrome presents with paradoxical thrombosis and an artifactual, non-correcting prolonged aPTT.

Step-by-Step Solution

1
Analyze presentation 1 focusing on mucosal bleeding and prolonged bleeding time.
Identify von Willebrand disease.
Prolonged bleeding time with normal platelets indicates a platelet function defect, typical of vWD which also sometimes prolongs aPTT.
2
Analyze presentation 2 focusing on joint bleeding and prolonged aPTT that corrects.
Identify Hemophilia A.
Correction on a mixing study confirms a factor deficiency (Factor VIII or IX) rather than an inhibitor. Hemarthrosis is classic for hemophilia.
3
Analyze presentation 3 focusing on sepsis and consumptive coagulopathy.
Identify Disseminated intravascular coagulation (DIC).
Simultaneous depletion of platelets and coagulation factors (prolonging both PT and aPTT) with elevated D-dimer is the hallmark of DIC.
4
Analyze presentation 4 focusing on isolated prolonged PT in an anticoagulated patient.
Identify Vitamin K antagonist effect.
Warfarin inhibits vitamin K-dependent factors. Factor VII has the shortest half-life, so PT prolongs before aPTT.
5
Analyze presentation 5 focusing on thrombosis, recurrent miscarriages, and non-correcting aPTT.
Identify Antiphospholipid syndrome.
A prolonged aPTT that fails to correct with normal plasma indicates the presence of an inhibitor (lupus anticoagulant), which is paradoxically prothrombotic.

Key Concept

Differentiation of bleeding and thrombotic disorders using clinical presentation, platelet count, PT, aPTT, and mixing studies.
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Topics

Hematology and Oncology

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