Returning to the swollen leg

Recall that the patient initially presented with a swollen right leg. The macrocytic anemia was an incidental finding. What does the differential diagnosis for a swollen leg include?

The patient had an doppler ultrasound of the right leg. The following is the result:

Are you familiar with a connection between vitamin B12 deficiency and increased risk for venous thromboembolism?

What is the connection?

Click for Answer

Increased homocysteine levels, which occur in vitamin B12 deficiency, have been linked to increased risk of thrombosis

Although it is a contested area, some believe that homocysteine is a modifiable risk factor of myocardial infarction, peripheral arterial thrombosis, as well as deep vein thrombosis and pulmonary embolism.

Hyperhomocysteinemia may result from:

• Genetic defects in the enzymes involved in homocysteine metabolism:
  • MTHFR
  • Methionine synthase 
• Deficiencies of enzymes cofactors:
  • Vitamin B6
  • Vitamin B12

See recent case series of patients with pernicious anemia presenting with venous thrombosis.

Our patient did not have homocysteine levels measured. He was treated for his deep venous thrombosis with 3 months of anticoagulation (DOAC).