Which two major tributary vessels are often mistaken for the GSV above the knee?

The anterior accessory saphenous vein and posterior accessory saphenous vein are commonly confused with the great saphenous vein (GSV) due to their anatomical proximity and similar appearance. These accessory veins run parallel to the GSV and often drain into it, which can lead to misinterpretation during venous ultrasound examinations.

The anterior accessory saphenous vein is located anterior to the GSV, while the posterior accessory saphenous vein is located behind it. Their close relationship in the thigh, along with their variable branching patterns, can make differentiation challenging, especially when visualizing the veins above the knee. Correctly identifying these veins is crucial for accurate assessments in phlebology, as misplaced diagnoses can influence treatment decisions.

In contrast, the other listed vein pairs do not share the same anatomical relationship with the GSV above the knee, making them less likely to be mistaken for it during evaluations.