Gross Anatomy

Question:

A 12-year-old boy is brought to the physician by his father because of redness and swelling of his left foot for 24 hours. Three days ago, the boy scraped his foot while wading in a drainage ditch. Examination of the left foot shows a purulent abrasion with edema, erythema, and tenderness on the lateral side. Infection is most likely to next spread from the lateral side of the foot to the regional lymph nodes in which of the following areas?

Correct Answer: C.  Popliteal fossa

The boy’s wound appears to be superficial – he “scraped” his foot which is now infected (likely by a Gram positive organism such as Strep A or Staph). The superficial lymphatic drainage of the lower extremity roughly follows the superficial vessels. In this case of the lateral foot, the lymphatics drain along the path of the small saphenous vein to the popliteal fossa.