Rosh Internal Medicine Boost Practice Exam

In a patient with a history of DVT presenting with lower extremity swelling, what is the most likely underlying condition if they have a low platelet count?

1. Antiphospholipid antibody syndrome

2. Atrial myxoma

3. Heterozygous factor V Leiden

4. Malignancy associated thrombosis

The correct answer is: Antiphospholipid antibody syndrome

In a patient with a history of deep vein thrombosis (DVT) presenting with lower extremity swelling and a low platelet count, the most likely underlying condition is antiphospholipid antibody syndrome. This syndrome is characterized by the presence of antiphospholipid antibodies, which can lead to hypercoagulability and an increased risk of venous and arterial thromboembolism. The association between antiphospholipid syndrome and low platelet counts can occur due to the presence of thrombocytopenia, which is often seen in patients who have an immune-mediated process affecting the platelets. In internal medicine, it is important to consider that individuals with antiphospholipid syndrome may have recurrent thrombotic events, and some may also develop thrombocytopenia. Other conditions mentioned may also be related to thrombosis but have different underlying mechanisms or are less likely to present with both a history of DVT and low platelet counts. For instance, atrial myxomas can lead to systemic embolization but do not typically cause thrombocytopenia. Heterozygous factor V Leiden primarily predisposes individuals to clotting but does not directly cause low platelet counts. Malignancy-associated thrombosis is a possibility and can lead to