Differential Diagnosis for Left Calf Swelling

The patient presents with left calf swelling following an 11-hour flight from Argentina, which is a significant risk factor for certain conditions. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Deep Vein Thrombosis (DVT): The patient's recent long-haul flight increases the risk of DVT due to prolonged immobilization, which can lead to blood clot formation. The symptoms of calf swelling, pain, and tenderness are consistent with DVT.

• Other Likely Diagnoses

  • Muscle Strain: Although the patient denies any injury, muscle strain could still be a possibility, especially if the patient engaged in unusual physical activity during or after the flight.
  • Superficial Thrombophlebitis: Inflammation of superficial veins can cause pain, swelling, and tenderness, similar to DVT but typically less severe and not as deep.
  • Cellulitis: A bacterial infection of the skin and subcutaneous tissues could cause swelling, pain, and tenderness, but it usually presents with additional signs like redness and warmth.

• Do Not Miss Diagnoses

  • Pulmonary Embolism (PE) with DVT: Although the patient denies shortness of breath, it's crucial to consider PE, especially if DVT is confirmed, as PE can be asymptomatic until it becomes life-threatening.
  • Ruptured Baker's Cyst: A ruptured Baker's cyst can cause calf swelling and pain, mimicking DVT, and is a significant differential to consider due to its potential to cause severe symptoms.

• Rare Diagnoses

  • Popliteal Artery Aneurysm or Thrombosis: These conditions can cause acute limb ischemia, presenting with pain, swelling, and potentially pallor and pulselessness of the affected limb.
  • Lymphedema: Although less likely given the acute onset, lymphedema could cause swelling, but it typically doesn't present with pain and tenderness.
  • Compartment Syndrome: This is a serious condition that could cause severe pain, swelling, and potentially neurovascular compromise, but it's less common in the context provided and usually follows significant trauma or reperfusion injury.