Dorsalis pedis tendon sheath cysts often occur lateral to the dorsalis pedis artery, next to the extensor digitorum longus tendon sheath. Common differential diagnoses of superficial tumors are dermatomal cysts, giant cell tumors of the tendon sheath, lipomas, fibromas, etc. The easiest and quickest differential is color ultrasound, which can often diagnose tendon sheath cysts more definitively. In patients with dermatomal cysts, there is usually a clear history of trauma, and giant cell tumors of the tendon sheath are harder in texture than tendon sheath cysts. Lipomas are more extensive to the touch than tendon sheath cysts, are not as well defined, and have a softer texture than tendon sheath cysts. Fibromas tend not to be as large and have a harder texture. Rheumatoid nodular hyperplasia can be initially differentially diagnosed by taking a radiograph.