A 67-year-old man shows signs of redness and a firm cord along the cephalic vein. What is the most likely diagnosis?

The presentation of redness and a firm cord along the cephalic vein in this 67-year-old man is characteristic of thrombophlebitis. Thrombophlebitis involves inflammation of a vein due to a thrombus (blood clot) that has formed within it, leading to symptoms such as redness, swelling, warmth, and tenderness along the affected vein.

In this case, the appearance of a firm cord suggests a palpable thrombus in the superficial venous system (the cephalic vein). Thrombophlebitis is most commonly seen in the superficial veins of the limbs, particularly after trauma, surgery, or prolonged immobility. The redness indicates inflammation associated with the thrombus, which differentiates it from other conditions like deep vein thrombosis that typically occurs in deeper veins and may not present with visible signs like a firm cord.

The other options do not fit the clinical scenario as closely. Deep vein thrombosis primarily occurs in deeper veins and is often associated with other symptoms such as leg swelling and pain, which are not mentioned here. Septic embolism is characterized by the presence of infected emboli leading to systemic infection and would present with more systemic signs. Superficial thrombophlebitis, while similar